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Sample records for management scheme based

  1. Key Updating Methods for Combinatorial Design Based Key Management Schemes

    Directory of Open Access Journals (Sweden)

    Chonghuan Xu

    2014-01-01

    Full Text Available Wireless sensor network (WSN has become one of the most promising network technologies for many useful applications. However, for the lack of resources, it is different but important to ensure the security of the WSNs. Key management is a corner stone on which to build secure WSNs for it has a fundamental role in confidentiality, authentication, and so on. Combinatorial design theory has been used to generate good-designed key rings for each sensor node in WSNs. A large number of combinatorial design based key management schemes have been proposed but none of them have taken key updating into consideration. In this paper, we point out the essence of key updating for the unital design based key management scheme and propose two key updating methods; then, we conduct performance analysis on the two methods from three aspects; at last, we generalize the two methods to other combinatorial design based key management schemes and enhance the second method.

  2. A State-Based Dynamic Location Management Scheme

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    We consider a state-based dynamic location management scheme, in which, the user is partitioned into different mobility state set. And its location area size is changed dynamically corresponding to the state set that it belongs to. Comparing with the fixed LA scheme, numerical experiment result shows it's performance can be improved by 30% while the current location and paging procedure can still be applied. Besides, as this scheme need not process complicated user information, the requirement of computing power decreases significantly than the user-based schemes. Our scheme can be used in current 2G mobile systems (such as GSM, CDMA) and the third generation (3G) mobile systems with slightly modifying of the equipment software.

  3. C60-based clustering scheme for sensor management in STSS

    Institute of Scientific and Technical Information of China (English)

    Yiyu Zhou

    2015-01-01

    Clustering-based sensor-management schemes have been widely used for various wireless sensor networks (WSNs), as they are wel suited to the distributive and col aborative nature of WSN. In this paper, a C60-based clustering algorithm is proposed for the specific planned network of space tracking and surveil ance system (STSS), where al the sensors are partitioned into 12 clus-ters according to the C60 (or footbal surface) architecture, and then a hierarchical sensor-management scheme is wel designed. Final y, the algorithm is applied to a typical STSS constel ation, and the simulation results show that the proposed method has bet-ter target-tracking performance than the nonclustering scheduling method.

  4. Triangle-based key management scheme for wireless sensor networks

    Institute of Scientific and Technical Information of China (English)

    Hangyang DAI; Hongbing XU

    2009-01-01

    For security services in wireless sensor net-works, key management is a fundamental building block.In this article, we propose a triangle-based key predis-tribution approach and show that it can improve the effectiveness of key management in wireless sensor networks. This is achieved by using the bivariate polynomial in a triangle deployment system based on deployment information about expected locations of the sensor nodes. The analysis indicates that this scheme can achieve higher probability of both direct key establishment and indirect key establishment. On the other hand, the security analysis shows that its security against node capture would increase with a decrease of the sensor node deployment density and size of the deployment model and an increase of the polynomial degree.

  5. An Extended Energy Consumption Analysis of Reputation-based Trust Management Schemes of Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Riaz Ahmed Shaikh

    2010-03-01

    Full Text Available Energy consumption is one of the most important parameters for evaluation of a scheme proposed for wireless sensor networks (WSNs because of their resource constraint nature. Comprehensive comparative analysis of proposed reputation-based trust management schemes of WSNs from this perspective is currently not available in the literature. In this paper, we have presented a theoretical and simulation based energy consumption analysis and evaluation of three state-of-the-art reputation-based trust management schemes of WSNs. Results show that the GTMS scheme consume less energy as compared with the RFSN and PLUS schemes.

  6. A Council-based Distributed Key Management Scheme for MANETs

    Directory of Open Access Journals (Sweden)

    Mohammed ELKOUTBI

    2010-09-01

    Full Text Available Abstract—Mobile ad hoc networks (MAETs have beenproposed as an extremely flexible technology for establishingwireless communications. In comparison with fixed networks,some new security issues have arisen with the introduction ofMAETs. Secure routing, in particular, is an important andcomplicated issue. Clustering is commonly used in order to limitthe amount of secure routing information. In this work, wepropose an enhanced solution for ad hoc key management basedon a cauterized architecture. This solution uses clusters as aframework to manage cryptographic keys in a distributed way.This paper sheds light on the key management algorithm for theOLSR protocol standard. Our algorithm takes into account thenode mobility and engenders major improvements regarding thenumber of elected cluster heads to create a PKI council. Ourobjective is to distribute the certification authority functions for areduced and less mobile cluster heads that will serve for keysexchange.

  7. A Dynamic Key Management Scheme Based on Secret Sharing for Hierarchical Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Enjian Bai

    2013-01-01

    Full Text Available Since wireless sensor networks (WSN for short are often deployed in hostile environments in many applications, security becomes one of the critical issues in WSN. Moreover, due to the limitation of the sensor nodes, traditional key management schemes are not suitable for it. Thereby,a feasible and efficient key management scheme is an important guarantee for WSN to communicate securely. For the moment, many protocols have been proposed and each has its own advantages. However, these protocols cannot provide sufficient security in many cases, such as node capture attack, which makes WSN more vulnerable than traditional wireless networks. Key protection and revocation issues must be considered with special attention in WSN. To address these two issues, we propose a dynamically clustering key management scheme based on secret sharing for WSN. The scheme combined the hierarchical structure of wireless sensor networks with dynamic key management scheme. The analysis results show that the scheme has strong security and resistance of captured attack, as well as low communicational overhead, and it well meets the requirement of scalability.

  8. Key Management Scheme Based on Route Planning of Mobile Sink in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Ying Zhang

    2016-01-01

    Full Text Available In many wireless sensor network application scenarios the key management scheme with a Mobile Sink (MS should be fully investigated. This paper proposes a key management scheme based on dynamic clustering and optimal-routing choice of MS. The concept of Traveling Salesman Problem with Neighbor areas (TSPN in dynamic clustering for data exchange is proposed, and the selection probability is used in MS route planning. The proposed scheme extends static key management to dynamic key management by considering the dynamic clustering and mobility of MSs, which can effectively balance the total energy consumption during the activities. Considering the different resources available to the member nodes and sink node, the session key between cluster head and MS is established by modified an ECC encryption with Diffie-Hellman key exchange (ECDH algorithm and the session key between member node and cluster head is built with a binary symmetric polynomial. By analyzing the security of data storage, data transfer and the mechanism of dynamic key management, the proposed scheme has more advantages to help improve the resilience of the key management system of the network on the premise of satisfying higher connectivity and storage efficiency.

  9. A MULTICAST KEY MANAGEMENT SCHEME BASED ON CHARACTERISTIC VALUES OF MEMBERS

    Institute of Scientific and Technical Information of China (English)

    Du Xiaoqiang; Bao Wansu; Fu Xiangqun

    2012-01-01

    A new collusion attack on Pour-like schemes is proposed in this paper.Then,we present a collusion-free centralized multicast key management scheme based on characteristic values of members.The re-keying method that other group members calculate new keys when a member is joining or leaving is also designed.It achieves forward secrecy and backward secrecy.Compared with typical existing centralized schemes,the storage of Group Key Controller (GKC) in our scheme halves the storage overhead of others,and communication overhead of GKC is 2 in case of joining re-keying.Especially,the leaving re-keying overhead is log2 n,and the overall performance is excellent.

  10. A Hybrid Key Management Scheme for WSNs Based on PPBR and a Tree-Based Path Key Establishment Method.

    Science.gov (United States)

    Zhang, Ying; Liang, Jixing; Zheng, Bingxin; Chen, Wei

    2016-04-09

    With the development of wireless sensor networks (WSNs), in most application scenarios traditional WSNs with static sink nodes will be gradually replaced by Mobile Sinks (MSs), and the corresponding application requires a secure communication environment. Current key management researches pay less attention to the security of sensor networks with MS. This paper proposes a hybrid key management schemes based on a Polynomial Pool-based key pre-distribution and Basic Random key pre-distribution (PPBR) to be used in WSNs with MS. The scheme takes full advantages of these two kinds of methods to improve the cracking difficulty of the key system. The storage effectiveness and the network resilience can be significantly enhanced as well. The tree-based path key establishment method is introduced to effectively solve the problem of communication link connectivity. Simulation clearly shows that the proposed scheme performs better in terms of network resilience, connectivity and storage effectiveness compared to other widely used schemes.

  11. A new Hierarchical Group Key Management based on Clustering Scheme for Mobile Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Ayman EL-SAYED

    2014-05-01

    Full Text Available The migration from wired network to wireless network has been a global trend in the past few decades because they provide anytime-anywhere networking services. The wireless networks are rapidly deployed in the future, secure wireless environment will be mandatory. As well, The mobility and scalability brought by wireless network made it possible in many applications. Among all the contemporary wireless networks,Mobile Ad hoc Networks (MANET is one of the most important and unique applications. MANET is a collection of autonomous nodes or terminals which communicate with each other by forming a multihop radio network and maintaining connectivity in a decentralized manner. Due to the nature of unreliable wireless medium data transfer is a major problem in MANET and it lacks security and reliability of data. The most suitable solution to provide the expected level of security to these services is the provision of a key management protocol. A Key management is vital part of security. This issue is even bigger in wireless network compared to wired network. The distribution of keys in an authenticated manner is a difficult task in MANET. When a member leaves or joins the group, it needs to generate a new key to maintain forward and backward secrecy. In this paper, we propose a new group key management schemes namely a Hierarchical, Simple, Efficient and Scalable Group Key (HSESGK based on clustering management scheme for MANETs and different other schemes are classified. Group members deduce the group key in a distributed manner.

  12. A security-awareness virtual machine management scheme based on Chinese wall policy in cloud computing.

    Science.gov (United States)

    Yu, Si; Gui, Xiaolin; Lin, Jiancai; Tian, Feng; Zhao, Jianqiang; Dai, Min

    2014-01-01

    Cloud computing gets increasing attention for its capacity to leverage developers from infrastructure management tasks. However, recent works reveal that side channel attacks can lead to privacy leakage in the cloud. Enhancing isolation between users is an effective solution to eliminate the attack. In this paper, to eliminate side channel attacks, we investigate the isolation enhancement scheme from the aspect of virtual machine (VM) management. The security-awareness VMs management scheme (SVMS), a VMs isolation enhancement scheme to defend against side channel attacks, is proposed. First, we use the aggressive conflict of interest relation (ACIR) and aggressive in ally with relation (AIAR) to describe user constraint relations. Second, based on the Chinese wall policy, we put forward four isolation rules. Third, the VMs placement and migration algorithms are designed to enforce VMs isolation between the conflict users. Finally, based on the normal distribution, we conduct a series of experiments to evaluate SVMS. The experimental results show that SVMS is efficient in guaranteeing isolation between VMs owned by conflict users, while the resource utilization rate decreases but not by much.

  13. A Security-Awareness Virtual Machine Management Scheme Based on Chinese Wall Policy in Cloud Computing

    Directory of Open Access Journals (Sweden)

    Si Yu

    2014-01-01

    Full Text Available Cloud computing gets increasing attention for its capacity to leverage developers from infrastructure management tasks. However, recent works reveal that side channel attacks can lead to privacy leakage in the cloud. Enhancing isolation between users is an effective solution to eliminate the attack. In this paper, to eliminate side channel attacks, we investigate the isolation enhancement scheme from the aspect of virtual machine (VM management. The security-awareness VMs management scheme (SVMS, a VMs isolation enhancement scheme to defend against side channel attacks, is proposed. First, we use the aggressive conflict of interest relation (ACIR and aggressive in ally with relation (AIAR to describe user constraint relations. Second, based on the Chinese wall policy, we put forward four isolation rules. Third, the VMs placement and migration algorithms are designed to enforce VMs isolation between the conflict users. Finally, based on the normal distribution, we conduct a series of experiments to evaluate SVMS. The experimental results show that SVMS is efficient in guaranteeing isolation between VMs owned by conflict users, while the resource utilization rate decreases but not by much.

  14. Trust-based hexagonal clustering for efficient certificate management scheme in mobile ad hoc networks

    Indian Academy of Sciences (India)

    V S JANANI; M S K MANIKANDAN

    2016-10-01

    The wireless and dynamic nature of mobile ad hoc networks (MANET) render them more vulnerable to security attacks. However, providing a security mechanism implicitly has been a major challenge in such an ad-hoc environment. Certificate management plays an important role in securing an ad-hoc network.Certificate assignment, verification, and revocation complexity associated with the Public Key Infrastructure (PKI) framework is significantly large. Smaller the size of the network lesser will be the certificate management complexity. However, smaller the size, large will be the overall infrastructural cost, and also larger will be the overall redundant certificates due to multiple certificate assignment at the boundary regions, that in turn affects the prompt and accurate certificate revocation. By taking these conflicting requirements into consideration, we propose the trust-based hexagonal clustering for an efficient certificate management (THCM) scheme, to bear an absolutely protected MANET Disparate to the existing clustering techniques, we present a hexagonal geographicclustering model with Voronoi technique where trust is accomplished. In particular, to compete against attackers, we initiate a certificate management strategy in which certificate assignment, verification, and revocation are carried out efficiently. The performance of THCM is evaluated by both simulation and empirical analysis in terms of effectiveness of revocation scheme (with respect to revocation rate and time), security, and communication cost. Besides, we conduct a mathematical analysis of measuring the parameters obtained from the two platforms in multiple times. Relevant results demonstrate that our design is efficient to guarantee a secured mobile ad hoc network.

  15. A Location-aware and Secret-share Based Dynamic Key Management Scheme for Heterogeneous Sensor Networks

    Directory of Open Access Journals (Sweden)

    Chunguang Ma

    2010-04-01

    Full Text Available Recently, Numerous dynamic key management schemes have been proposed for WSN, and it has long-lived networks, more sustained security and survivability, such as SHELL and LCOK. But most of these schemes are greatly depend on some central nodes (gateways, if these nodes were compromised, there will be great threat to the whole networks security and survivability. In this paper, we proposed a Location-aware and secret share based dynamic key management scheme to effectively replace the compromised central node and enhance the security level of the network.

  16. A Cooperative QoS Management Scheme Based on DiffServ Network for Real-Time Service

    Institute of Scientific and Technical Information of China (English)

    ZHAO Dong-ping; ZHANG De-yun; ZHANG Jun; AN Zhi-ping

    2004-01-01

    In this paper, an improved scheme based on DiffServ network is proposed to provide a decentralized cooperative QoS management for real-time services' admission control and resources' monitoring. The proposed scheme consists of a QoS Control Server (QoSCS), a Service Management Server (SMS), a Network Management Server (NMS) and routers in the concerned management domain. When an application asks for a service with specific QoS requirements, a series of cooperation are initiated among these components by means of a suit of signaling protocol. Once a service is admitted, it can provide required QoS services more effectively than original Di ffServ network. Monitoring per-flow states are moved from edge routers to the QoSCS server. The prototype implementation and experimental results show that this scheme can provide enhanced manageability and scalability for providing per-flow management in such a distributed way.

  17. A reliable p ower management scheme for consistent hashing based distributed key value storage systems#

    Institute of Scientific and Technical Information of China (English)

    Nan-nan ZHAO; Ji-guang WAN; Jun WANG; Chang-sheng XIE

    2016-01-01

    Distributed key value storage systems are among the most important types of distributed storage systems currently deployed in data centers. Nowadays, enterprise data centers are facing growing pressure in reducing their power consumption. In this paper, we propose GreenCHT, a reliable power management scheme for consistent hashing based distributed key value storage systems. It consists of a multi-tier replication scheme, a reliable distributed log store, and a predictive power mode scheduler (PMS). Instead of randomly placing replicas of each object on a number of nodes in the consistent hash ring, we arrange the replicas of objects on nonoverlapping tiers of nodes in the ring. This allows the system to fall in various power modes by powering down subsets of servers while not violating data availability. The predictive PMS predicts workloads and adapts to load fluctuation. It cooperates with the multi-tier replication strategy to provide power proportionality for the system. To ensure that the reliability of the system is maintained when replicas are powered down, we distribute the writes to standby replicas to active servers, which ensures failure tolerance of the system. GreenCHT is implemented based on Sheepdog, a distributed key value storage system that uses consistent hashing as an underlying distributed hash table. By replaying 12 typical real workload traces collected from Microsoft, the evaluation results show that GreenCHT can provide significant power savings while maintaining a desired performance. We observe that GreenCHT can reduce power consumption by up to 35%–61%.

  18. WQM: An Aggregation-aware Queue Management Scheme for IEEE 802.11n based Networks

    KAUST Repository

    Showail, Ahmad

    2014-08-17

    Choosing the right buffer size in Wi-Fi networks is challenging due to the dynamic nature of the wireless environment. Over buffering or \\'bufferbloat\\' may produce unacceptable end-to-end delays, while static small buffers may limit the performance gains that can be achieved with various 802.11n enhancements, such as frame aggregation. We propose WQM, a queue management scheme customized for wireless networks. WQM adapts the buffer size based on measured link characteristics and network load. Furthermore, it accounts for aggregate length when deciding about the optimal buffer size. We implement WQM on Linux and evaluate it on a wireless testbed. WQM reduces the end-to-end delay by up to 8x compared to Linux default buffer size, and 2x compared to CoDel, the state-of-the-art bufferbloat solution, while achieving comparable network goodput. Further, WQM improves fairness as it limits the ability of a single flow to saturate the buffer.

  19. A novel key management scheme using biometrics

    Science.gov (United States)

    Sui, Yan; Yang, Kai; Du, Yingzi; Orr, Scott; Zou, Xukai

    2010-04-01

    Key management is one of the most important issues in cryptographic systems. Several important challenges in such a context are represented by secure and efficient key generation, key distribution, as well as key revocation. Addressing such challenges requires a comprehensive solution which is robust, secure and efficient. Compared to traditional key management schemes, key management using biometrics requires the presence of the user, which can reduce fraud and protect the key better. In this paper, we propose a novel key management scheme using iris based biometrics. Our newly proposed scheme outperforms traditional key management schemes as well as some existing key-binding biometric schemes in terms of security, diversity and/or efficiency.

  20. SMR-Based Adaptive Mobility Management Scheme in Hierarchical SIP Networks

    Directory of Open Access Journals (Sweden)

    KwangHee Choi

    2014-10-01

    Full Text Available In hierarchical SIP networks, paging is performed to reduce location update signaling cost for mobility management. However, the cost efficiency largely depends on each mobile node’s session-to-mobility-ratio (SMR, which is defined as a ratio of the session arrival rate to the movement rate. In this paper, we propose the adaptive mobility management scheme that can determine the policy regarding to each mobile node’s SMR. Each mobile node determines whether the paging is applied or not after comparing its SMR with the threshold. In other words, the paging is applied to a mobile node when a mobile node’s SMR is less than the threshold. Therefore, the proposed scheme provides a way to minimize signaling costs according to each mobile node’s SMR. We find out the optimal threshold through performance analysis, and show that the proposed scheme can reduce signaling cost than the existing SIP and paging schemes in hierarchical SIP networks.

  1. Dynamic Buffer Management Scheme Based on Rate Estimation in Packet-Switched Networks

    OpenAIRE

    Cho, Jeong-woo; Cho, Dong-Ho

    2002-01-01

     While traffic volume of real-time applications is rapidly increasing, current routers do not guarantee minimum QoS values of fairness and drop packets in random fashion. If routers provide a minimum QoS, resulting less delays, more fairness, and smoother sending rates, TCP-friendly rate control (TFRC) can be adopted for real-time applications. We propose a dynamic buffer management scheme that meets the requirements described above, and can be applied to TCP flow and to data flow for transfe...

  2. The performance evaluation of a new neural network based traffic management scheme for a satellite communication network

    Science.gov (United States)

    Ansari, Nirwan; Liu, Dequan

    1991-01-01

    A neural-network-based traffic management scheme for a satellite communication network is described. The scheme consists of two levels of management. The front end of the scheme is a derivation of Kohonen's self-organization model to configure maps for the satellite communication network dynamically. The model consists of three stages. The first stage is the pattern recognition task, in which an exemplar map that best meets the current network requirements is selected. The second stage is the analysis of the discrepancy between the chosen exemplar map and the state of the network, and the adaptive modification of the chosen exemplar map to conform closely to the network requirement (input data pattern) by means of Kohonen's self-organization. On the basis of certain performance criteria, whether a new map is generated to replace the original chosen map is decided in the third stage. A state-dependent routing algorithm, which arranges the incoming call to some proper path, is used to make the network more efficient and to lower the call block rate. Simulation results demonstrate that the scheme, which combines self-organization and the state-dependent routing mechanism, provides better performance in terms of call block rate than schemes that only have either the self-organization mechanism or the routing mechanism.

  3. An ANN Based Call Handoff Management Scheme for Mobile Cellular Network

    Directory of Open Access Journals (Sweden)

    P. P. Bhattacharya

    2013-12-01

    Full Text Available Handoff decisions are usually signal strength based because of simplicity and effectiveness. Apart fro m the conventional techniques, such as threshold and hyst eresis based schemes, recently many artificial intelligent techniques such as Fuzzy Logic, Artific ial Neural Network (ANN etc. are also used for tak ing handoff decision. In this paper, an Artificial Neur al Network based handoff algorithm is proposed and it’s performance is studied. We have used ANNhere for ta king fast and accurate handoff decision. In our proposed handoff algorithm, Backpropagation Neural Network model is used.The advantages of Backpropagation method are its simplicity and reaso nable speed. The algorithm is designed, tested and found to give optimum results.

  4. A distributed scheme to manage the dynamic coexistence of IEEE 802.15.4-based health-monitoring WBANs.

    Science.gov (United States)

    Deylami, Mohammad N; Jovanov, Emil

    2014-01-01

    The overlap of transmission ranges between wireless networks as a result of mobility is referred to as dynamic coexistence. The interference caused by coexistence may significantly affect the performance of wireless body area networks (WBANs) where reliability is particularly critical for health monitoring applications. In this paper, we analytically study the effects of dynamic coexistence on the operation of IEEE 802.15.4-based health monitoring WBANs. The current IEEE 802.15.4 standard lacks mechanisms for effectively managing the coexistence of mobile WBANs. Considering the specific characteristics and requirements of health monitoring WBANs, we propose the dynamic coexistence management (DCM) mechanism to make IEEE 802.15.4-based WBANs able to detect and mitigate the harmful effects of coexistence. We assess the effectiveness of this scheme using extensive OPNET simulations. Our results indicate that DCM improves the successful transmission rates of dynamically coexisting WBANs by 20%-25% for typical medical monitoring applications.

  5. COST-EFFICIENT RESIDENTIAL ENERGY MANAGEMENT SCHEME FOR INFORMATION-CENTRIC NETWORKING BASED HOME NETWORK IN SMART GRID

    Directory of Open Access Journals (Sweden)

    Keping Yu

    2016-03-01

    Full Text Available Home network (HOMENET performs multiple important functions such as energy management, multimedia sharing, lighting and climate control in smart grid (SG. In HOMENET there are numerous challenges among which mobility and security are the basic requirements that need to be addressed with priority. The information-centric networking (ICN is regarded as the future Internet that subscribes data in a content-centric manner irrespective of its location. Furthermore, it has pecial merit in mobility and security since ICN supports in-network caching and self-contained security, these make ICN a potential solution for home communication fabric. This paper aims to apply the ICN approach on HOMENET system, which we called ICN-HOMENET. Then, a proof-of-concept evaluation is employed to evaluate the effectiveness of the proposed ICN-HOMENET approach in data security, device mobility and efficient content distribution for developing HOMENET system in SG. In addition, we proposed a cost-efficient residential energy management (REM scheme called ICN-REM scheme for ICN-HOMENET system which encourages consumers to shift the start time of appliances from peak hours to off-peak hours to reduce the energy bills. To the best of our knowledge, this is the first attempt to propose an ICN-based REM scheme for HOMENET system. In this proposal, we not only consider the conflicting requests from appliances and domestic power generation, but also think the energy management unit (EMU should cooperate with measurement sensors to control some specific appliances in some specific conditions. Moreover, the corresponding performance evaluation validates its correctness and effectiveness.

  6. A Cluster based Key Management Scheme for Underwater Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Seema Verma

    2015-08-01

    Full Text Available Underwater Wireless Sensor Networks (UWSNs explore aquatic environment to facilitate various underwater surveillance applications. However, UWSN unique features also impose new challenges such as limited bandwidth, huge propagation delay, mobile nature of nodes and high error rates. UWSNs deployment in unattended environment further exacerbates their vulnerabilities to the attacks. These challenges make security solutions proposed for Wireless Sensor Network (WSN impractical to be applicable for UWSN. This paper analyzes the problem of security and mobility in UWSN and proposes Cluster based Key management Protocol (CKP, a new key management protocol for hierarchical networks where sensor nodes form cluster around more capable nodes. CKP also proposes a new communication architecture that handles mobility efficiently and minimizes the impact of a node compromisation to itself. CKP provides confidentiality, authentication, integrity and freshness. The performance evaluation demonstrates that the CKP is energy and storage-efficient. Further, we investigate the survivability and the security of the CKP against various security threats in order to evaluate its effectiveness.

  7. Enhancing Access to Knowledge Management Literature — A Proposal for Domain-Based Classification Scheme and Thesaurus

    OpenAIRE

    Denise A. D. Bedford

    2015-01-01

    Knowledge organisation systems (KOS) include a variety of tools and methods for organising information and knowledge 'things'. When we refer to KOS we generally mean classification schemes, thesauri, semantic networks, and authority control systems. Most academic disciplines are supported by professionally developed and maintained KOS. This is not the case for knowledge management. Knowledge management is insufficiently treated in existing KOS. The research is exploratory in its approach to d...

  8. Developing a risk-based trading scheme for cattle in England: farmer perspectives on managing trading risk for bovine tuberculosis.

    Science.gov (United States)

    Little, R; Wheeler, K; Edge, S

    2017-02-11

    This paper examines farmer attitudes towards the development of a voluntary risk-based trading scheme for cattle in England as a risk mitigation measure for bovine tuberculosis (bTB). The research reported here was commissioned to gather evidence on the type of scheme that would have a good chance of success in improving the information farmers receive about the bTB risk of cattle they buy. Telephone interviews were conducted with a stratified random sample of 203 cattle farmers in England, splitting the interviews equally between respondents in the high-risk area and low-risk area for bTB. Supplementary interviews and focus groups with farmers were also carried out across the risk areas. Results suggest a greater enthusiasm for a risk-based trading scheme in low-risk areas compared with high-risk areas and among members of breed societies and cattle health schemes. Third-party certification of herds by private vets or the Animal and Plant Health Agency were regarded as the most credible source, with farmer self-certification being favoured by sellers, but being regarded as least credible by buyers. Understanding farmers' attitudes towards voluntary risk-based trading is important to gauge likely uptake, understand preferences for information provision and to assist in monitoring, evaluating and refining the scheme once established.

  9. Provable Secure Identity Based Generalized Signcryption Scheme

    CERN Document Server

    Yu, Gang; Shen, Yong; Han, Wenbao

    2010-01-01

    According to actual needs, generalized signcryption scheme can flexibly work as an encryption scheme, a signature scheme or a signcryption scheme. In this paper, firstly, we give a security model for identity based generalized signcryption which is more complete than existing model. Secondly, we propose an identity based generalized signcryption scheme. Thirdly, we give the security proof of the new scheme in this complete model. Comparing with existing identity based generalized signcryption, the new scheme has less implementation complexity. Moreover, the new scheme has comparable computation complexity with the existing normal signcryption schemes.

  10. A Distributed and Adaptive Location Management Scheme for Hierarchical Mobility Management

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Hierarchical mobility management is sensitive to the failure of gateway mobility agents and prone to degrade performance on heavy loads. This paper proposes a distributed and adaptive location management scheme based on Hierarchical Mobile IPv6. This scheme can balance the loads of mobility anchor points and increase the robustness of the hierarchical structure to certain extents. In this scheme, the optimized IP paging scheme is adopted to reduce the paging signaling cost and improve the scalability of the hierarchical mobility management. We implement the distributed and adaptive location management scheme in a simulation platform and compare its performance with that of two other location management schemes. Our simulation results show that our scheme is capable of balancing the signaling and traffic loads of mobility ancher points, decreasing the average handover latency, and increasing the throughout of the visited networks.

  11. Provable Secure Identity Based Generalized Signcryption Scheme

    OpenAIRE

    Yu, Gang; Ma, Xiaoxiao; Shen, Yong; Han, Wenbao

    2010-01-01

    According to actual needs, generalized signcryption scheme can flexibly work as an encryption scheme, a signature scheme or a signcryption scheme. In this paper, firstly, we give a security model for identity based generalized signcryption which is more complete than existing model. Secondly, we propose an identity based generalized signcryption scheme. Thirdly, we give the security proof of the new scheme in this complete model. Comparing with existing identity based generalized signcryption...

  12. Alternative Environmental Flow Management Schemes

    Science.gov (United States)

    2013-08-01

    may be of interest depending upon the objectives of a particular hydrologic analysis. For instance, a flood risk management project is likely ...consider many components of an aquatic ecosystem including geomorphology, hydraulic habitat, water quality, invertebrates, vertebrates (e.g., fish, mammals ...amphibians, birds, and reptiles ), adjacent riparian or floodplain vegetation communities, downstream estuarine communities in coastal rivers, and

  13. Adaptive mobility management scheme in hierarchical mobile IPv6

    Science.gov (United States)

    Fang, Bo; Song, Junde

    2004-04-01

    Hierarchical mobile IPv6 makes the mobility management localized. Registration with HA is only needed while MN moving between MAP domains. This paper proposed an adaptive mobility management scheme based on the hierarchical mobile IPv6. The scheme focuses on the MN operation as well as MAP operation during the handoff. Adaptive MAP selection algorithm can be used to select a suitable MAP to register with once MN moves into a new subnet while MAP can thus adaptively changing his management domain. Furthermore, MAP can also adaptively changes its level in the hierarchical referring on the service load or other related information. Detailed handoff algorithm is also discussed in this paper.

  14. Fair Electronic Payment Scheme Based on DSA

    Institute of Scientific and Technical Information of China (English)

    WANG Shao-bin; HONG Fan; ZHU Xian

    2005-01-01

    We present a multi-signature scheme based on DSA and describes a fair electronic payment scheme based on improved DSA signatures. The scheme makes both sides in equal positions during the course of electronic transaction. A Trusted Third Party (TTP) is involved in the scheme to guarantee the fairness of the scheme for both sides. However, only during the course of registration and dispute resolution will TTP be needed. TTP is not needed during the normal payment stage.

  15. Key Pre-Distribution Management Scheme for Wireless Sensor Based on Hash%基于Hash的无线传感器密钥预分配方案

    Institute of Scientific and Technical Information of China (English)

    余嘉; 许可; 彭文兵

    2011-01-01

    提出了一种基于查找表映射Hash的无线传感器网络密钥预分配管理方案.该方案利用查找表加密算法同时具有加密和生成Hash值的特性,动态地生成节点间通信的公共密钥.引入分簇节点方式来提高网络的连通性和存活率,并节省了存储空间.仿真结果及实验分析表明,本方案具有良好的安全性、连通性和抗捕获能力,并可有效地利用存储空间.%Key pre-distribution and management scheme of wireless sensor network based on Hash constructed by look-up table is proposed in this paper. The scheme dynamically generates the public keys for nodes communication through the look-up table encryption algorithm, which can encrypt and hash the text at the same time. To improve the connectivity and livability of the network and also to save the memory, the clustered sensor network style is introduced. Theoretical analysis and computer simulation indicate that the presented scheme can improve the performance of security, connectivity, anti-captured ability and can effectively utilize the memory as well.

  16. Certificateless Efficient Group Key Management Scheme in Mobile Adhoc Networks

    Directory of Open Access Journals (Sweden)

    Sanjeev Kumar Rana

    2011-03-01

    Full Text Available Securing mobile ad hoc networks (MANETs is a crucial task for their good deployments. One fundamental aspect of providing confidentiality and authentication is key management. While Public Key Infrastructure (PKI based solutions has provided these properties historically, MANETs are resource constrained and benefit from symmetric key encryption. In this paper, we proposed a certificateless efficient group key management scheme (CE-GKMS in MANETs for group confidentiality which uses identity based cryptography for secure multicast group communication. The scheme does not need PKI in which mobile nodes needs large storage to carry certificates and to perform public key cryptography based large computation. The scheme introduced a new idea of hiding the public keys and making them visible only to the trusted nodes which not only make it difficult for cryptanalyst to crack the private information but also permit to keep small value of encryption and decryption component causes asymmetric cryptography operation faster. For scalability and dynamic reconfigurability, we divide the network into groups. Leaders in these groups securely communicate with each other to agree on group key in response to membership change and member mobility-induced events. The performance results prove the effectiveness of our proposed key management scheme CE-GKMS.

  17. Design and Analysis of a Dynamic Mobility Management Scheme for Wireless Mesh Network

    Directory of Open Access Journals (Sweden)

    Abhishek Majumder

    2013-01-01

    Full Text Available Seamless mobility management of the mesh clients (MCs in wireless mesh network (WMN has drawn a lot of attention from the research community. A number of mobility management schemes such as mesh network with mobility management (MEMO, mesh mobility management (M3, and wireless mesh mobility management (WMM have been proposed. The common problem with these schemes is that they impose uniform criteria on all the MCs for sending route update message irrespective of their distinct characteristics. This paper proposes a session-to-mobility ratio (SMR based dynamic mobility management scheme for handling both internet and intranet traffic. To reduce the total communication cost, this scheme considers each MC’s session and mobility characteristics by dynamically determining optimal threshold SMR value for each MC. A numerical analysis of the proposed scheme has been carried out. Comparison with other schemes shows that the proposed scheme outperforms MEMO, M3, and WMM with respect to total cost.

  18. Design and analysis of a dynamic mobility management scheme for wireless mesh network.

    Science.gov (United States)

    Majumder, Abhishek; Roy, Sudipta

    2013-01-01

    Seamless mobility management of the mesh clients (MCs) in wireless mesh network (WMN) has drawn a lot of attention from the research community. A number of mobility management schemes such as mesh network with mobility management (MEMO), mesh mobility management (M(3)), and wireless mesh mobility management (WMM) have been proposed. The common problem with these schemes is that they impose uniform criteria on all the MCs for sending route update message irrespective of their distinct characteristics. This paper proposes a session-to-mobility ratio (SMR) based dynamic mobility management scheme for handling both internet and intranet traffic. To reduce the total communication cost, this scheme considers each MC's session and mobility characteristics by dynamically determining optimal threshold SMR value for each MC. A numerical analysis of the proposed scheme has been carried out. Comparison with other schemes shows that the proposed scheme outperforms MEMO, M(3), and WMM with respect to total cost.

  19. 一种分层分簇的组密钥管理方案%A HIERARCHICAL CLUSTERING-BASED GROUP KEY MANAGEMENT SCHEME

    Institute of Scientific and Technical Information of China (English)

    李珍格; 游林

    2014-01-01

    为了满足无线传感器网络组通信的安全,提出一种分层分簇的组密钥管理方案。该方案采用分层的体系结构,将组中节点分为管理层和普通层。BS通过构造特殊的组密钥多项式更新普通层组密钥,而管理层则采用二元单向函数进行组密钥的协商。分析表明,该方案很好满足了无线传感器网络中组密钥管理的前向安全性,后向安全性,并且减小了存储开销、计算开销和通信开销。%In this paper,a hierarchical clustering-based group key management scheme is proposed in order to satisfy the secure group communication in wireless sensor network.The proposed scheme adopts the hierarchical architecture and divides the nodes in the group into master-node layer and terminal layer.The group key of terminal layer is updated by constructing a special group key polynomial in BS,and the binary one-way function is used by the master-node layer for group key negotiation.Analysis demonstrates that the scheme well satisfies the forward security and backward security of the group key management in WSN,and reduces the storage overhead,computation overhead and communication overhead as well.

  20. An efficient scalable key management scheme for secure group communication

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jun; GU Da-wu; MA Fan-yuan; BAI Ying-cai

    2006-01-01

    Several multicast key management schemes such as those proposed by Wallner et al and Wong et al are based on a multilevel, logical hierarchy (or tree) of key-encrypting keys. When used in conjunction with a reliable multicast infrastructure, this approach results in a highly efficient key update mechanism in which the number of multicast messages transmitted upon a membership update is proportional to the depth of the tree,which is logarithmic to the size of the secure multicast group. But this is based on the hypothesis that the tree is maintained in a balanced manner. This paper proposes a scalable rekeying scheme-link-tree structure for implementing secure group communication. Theoretical calculation and experimentation show that this scheme has better performance than the tree structure and the star structure, and at the same time still keep the link-tree structure balanced.

  1. Signcryption scheme based on schnorr digital signature

    CERN Document Server

    Savu, Laura

    2012-01-01

    This article presents a new signcryption scheme which is based on the Schnorr digital signature algorithm. The new scheme represents my personal contribution to signcryption area. I have been implemented the algorithm in a program and here are provided the steps of the algorithm, the results and some examples. The paper also contains the presentation of the original Signcryption scheme, based on ElGamal digital signature and discusses the practical applications of Signcryption in real life.

  2. An Identity-Based Encryption Scheme with Compact Ciphertexts

    Institute of Scientific and Technical Information of China (English)

    LIU Sheng-li; GUO Bao-an; ZHANG Qing-sheng

    2009-01-01

    This paper proposes an identity-based encryption scheme with the help of bilinear pairings, where the identity information of a user functions as the user's public key. The advantage of an identity-based public key system is that it can avoid public key certificates and certificate management. Our identity-based encryption scheme enjoys short ciphertexts and provable security against chosen-ciphertext attack (CCA).

  3. 基于身份的Ad Hoc网密钥管理方案%Identity-based key management scheme for Ad Hoc network

    Institute of Scientific and Technical Information of China (English)

    孙梅; 赵兵

    2012-01-01

    According to the characteristics of Ad Hoc networks, such as mobility and self-organization, an identity-based key management scheme for Ad Hoc networks was proposed. In the paper, by the method of secure distributed key generation based on threshold cryptography, the interior members of Ad Hoc networks collaborated to conduct the system private key. Compared with the existent protocol, the proposed scheme, does not require the fixed structure of service nodes, and service nodes can dynamically join and leave network. At the same time, the system key is updatable among service nodes. The analytical results show the proposed scheme is flexible and secure, and it is suitable for Mobile Ad Hoc Network ( MANET).%鉴于Ad Hoc网络的可移动、自组织性等优点,提出了一种适用于Ad Hoc网络的基于身份的密钥管理方案,所提方案在门限密码学的基础上以完全分布化方式建立系统密钥.与已有的Ad Hoc网络密钥管理方案相比,它不需要固定的密钥服务节点组,密钥服务节点可以动态加入和撤离,而且系统密钥在密钥服务节点组内还可以动态更新.分析结果表明所提方案具有灵活、安全的特点,较好地适应了移动自组网(MANET).

  4. Design and Analysis of a Multiscale Active Queue Management Scheme

    Institute of Scientific and Technical Information of China (English)

    Qi-Jin Ji; Yong-Qiang Dong

    2006-01-01

    Since Internet is dominated by TCP-based applications, active queue management (AQM) is considered as an effective way for congestion control. However, most AQM schemes suffer obvious performance degradation with dynamic traffic. Extensive measurements found that Internet traffic is extremely bursty and possibly self-similar. We propose in this paper a new AQM scheme called multiscale controller (MSC) based on the understanding of traffic burstiness in multiple time scale. Different from most of other AQM schemes, MSC combines rate-based and queue-based control in two time scales. While the rate-based dropping on burst level (large time scales) determines the packet drop aggressiveness and is responsible for low and stable queuing delay, good robustness and responsiveness, the queue-based modulation of the packet drop probability on packet level (small time scales) will bring low loss and high throughput. Stability analysis is performed based on a fluid-flow model of the TCP/MSC congestion control system and simulation results show that MSC outperforms many of the current AQM schemes.

  5. Architecture Aware Key Management Scheme for Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Mohammed FEHAM

    2012-11-01

    Full Text Available The emergence of wireless networking as well as the development in embedded systems and technologies have given birth to application specific networks called wireless sensor networks WSNs, their flexibility, facility of use and deployment as well as their low cost give them an increasing field of applications. Usually sensors are limited in capacities deployed in a hostile and unpredictable environment, making the security of these networks a challenging task. In this paper we are going to present a key management scheme in which the base station play the role of the secure third party responsible of distributing key and managing security in the network, two versions of this scheme are presented the first one for flat networks and the second one for hierarchical networks in which the cluster head play the key role in all key agreement with the base station.

  6. SIGNCRYPTION BASED ON DIFFERENT DIGITAL SIGNATURE SCHEMES

    OpenAIRE

    Adrian Atanasiu; Laura Savu

    2012-01-01

    This article presents two new signcryption schemes. The first one is based on Schnorr digital signature algorithm and the second one is using Proxy Signature scheme introduced by Mambo. Schnorr Signcryption has been implemented in a program and here are provided the steps of the algorithm, the results and some examples. The Mambo’s Proxy Signature is adapted for Shortened Digital Signature Standard, being part of a new Proxy Signcryption scheme.

  7. Efficient Identity Based Public Verifiable Signcryption Scheme

    CERN Document Server

    Kushwah, Prashant

    2011-01-01

    Signcryption is a cryptographic primitive which performs encryption and signature in a single logical step. In conventional signcryption only receiver of the signcrypted text can verify the authenticity of the origin i.e. signature of the sender on the message after decrypting the cipher text. In public verifiable signcryption scheme anyone can verify the authenticity of the origin who can access the signcrypted text i.e. signature of the sender on the cipher text. Public verifiable signcryption scheme in which the receiver can convince a third party, by providing additional information other than his private key along with the signcryption is called third party verifiable signcryption schemes. In this paper we proposed an efficient identity based public verifiable signcryption scheme with third party verification and proved its security in the random oracle model.

  8. Asymmetric Watermarking Scheme Based on Correlation Testing

    Directory of Open Access Journals (Sweden)

    Rinaldi Munir

    2007-06-01

    Full Text Available Abstract Asymmetric watermarking is the second generation of watermarking scheme which uses different keys for embedding and detecting watermark. Key for embedding is private or secret, but key for detecting can be available publicly and everyone who has the key can detect watermark Watermark detection does not need to be original multimedia data. Detection of watermark is realized using correlation test between public key and multimedia data received. In most of schemes, private key is the watermark itself; public key is public watermark which correlates to the private watermark This paper presents concept of asymmetric watermarking scheme that based on correlation test and reviews some schemes of asymmetric watermarking that have been proposed by researchers. Keywords: asymmetric watermarking, private key, public key, watermark., multimeelia,:correlation.

  9. An ECC-Based Blind Signature Scheme

    Directory of Open Access Journals (Sweden)

    Fuh-Gwo Jeng

    2010-08-01

    Full Text Available Cryptography is increasingly applied to the E-commerce world, especially to the untraceable payment system and the electronic voting system. Protocols for these systems strongly require the anonymous digital signature property, and thus a blind signature strategy is the answer to it. Chaum stated that every blind signature protocol should hold two fundamental properties, blindness and intractableness. All blind signature schemes proposed previously almost are based on the integer factorization problems, discrete logarithm problems, or the quadratic residues, which are shown by Lee et al. that none of the schemes is able to meet the two fundamental properties above. Therefore, an ECC-based blind signature scheme that possesses both the above properties is proposed in this paper.

  10. Identity-based signature scheme based on quadratic residues

    Institute of Scientific and Technical Information of China (English)

    CHAI ZhenChuan; CAO ZhenFu; DONG XiaoLei

    2007-01-01

    Identity-based (ID-based) cryptography has drawn great concerns in recent years, and most of ID-based schemes are constructed from bilinear parings. Therefore, ID-based scheme without pairing is of great interest in the field of cryptography. Up to now,there still remains a challenge to construct ID-based signature scheme from quadratic residues. Thus, we aim to meet this challenge by proposing a concrete scheme. In this paper, we first introduce the technique of how to calculate a 2lth root of a quadratic residue, and then give a concrete ID-based signature scheme using such technique.We also prove that our scheme is chosen message and ID secure in the random oracle model, assuming the hardness of factoring.

  11. Feasibility analysis of two identity- based proxy ring signature schemes

    Institute of Scientific and Technical Information of China (English)

    Wang Huaqun; Zhang Lijun; Zhao Junxi

    2007-01-01

    Recently , proxy ring signature schemes have been shown to be useful in various applications , such as electronic polling, electronic payment, etc. Although many proxy ring signature schemes have been proposed, there are only two identity- based proxy ring signature schemes have been proposed until now, I.e., Cheng's scheme and Lang's scheme. It's unlucky that the two identity- based proxy ring signature schemes are unfeasible . This paper points out the reasons why the two identity- based proxy ring signature schemes are unfeasible. In order to design feasible and efficient identity-based proxy ring signature schemes from bilinear pairings , we have to search for other methods .

  12. Secure SCADA communication by using a modified key management scheme.

    Science.gov (United States)

    Rezai, Abdalhossein; Keshavarzi, Parviz; Moravej, Zahra

    2013-07-01

    This paper presents and evaluates a new cryptographic key management scheme which increases the efficiency and security of the Supervisory Control And Data Acquisition (SCADA) communication. In the proposed key management scheme, two key update phases are used: session key update and master key update. In the session key update phase, session keys are generated in the master station. In the master key update phase, the Elliptic Curve Diffie-Hellman (ECDH) protocol is used. The Poisson process is also used to model the Security Index (SI) and Quality of Service (QoS). Our analysis shows that the proposed key management not only supports the required speed in the MODBUS implementation but also has several advantages compared to other key management schemes for secure communication in SCADA networks.

  13. A Distributed Network Mobility Management Scheme for Hierarchical Mobile IPv6 Networks

    Science.gov (United States)

    Kawano, Keita; Kinoshita, Kazuhiko; Yamai, Nariyoshi

    Route optimization for network mobility is a key technique for providing a node in a mobile network (Mobile Network Node or MNN) with high quality broadband communications. Many schemes adding route optimization function to Network Mobility (NEMO) Basic Support protocol, the standardized network mobility management protocol from the IETF nemo working group, have already been proposed in recent years. One such scheme, a scheme using Hierarchical Mobile IPv6 (HMIPv6) aims to overcome micromobility management issues as well by applying a mechanism based on HMIPv6. The traditional scheme, however, suffers from a significant number of signaling messages as the number of MNNs and/or the number of their Correspondent Nodes (CNs) increase, because many messages notifying the MNNs' Home Agents (HAMNNs) and the CNs of the mobile network's movement are generated simultaneously each time the mobile network moves to the domain of another micromobility management router (Mobility Anchor Point or MAP). This paper proposes a scheme to overcome this problem. Our scheme reduces the number of signaling messages generated at the same time by managing the mobility of MNNs using multiple MAPs distributed within a network for load sharing. The results of simulation experiments show that our scheme works efficiently compared to the traditional scheme when a mobile network has many MNNs and/or these MNNs communicate with many CNs.

  14. Management Specialists' Training Social Schemes: World Experience and Russian Specificity

    Directory of Open Access Journals (Sweden)

    М А Ignatskaya

    2010-06-01

    Full Text Available The article offers the analysis of the issues related to the social administration of professional management personnel training which have become particularly complicated over the past two decades. Social schemes, conditions and factors of management are shown to be closely interconnected with the characteristics of human capital as the basis for social, economic and cultural development of the contemporary society. World experience and Russian specificity in the sphere of human resource management specialists' training are analyzed.

  15. A Key Management Scheme for ZigBee in AMI of Smart Grid

    Institute of Scientific and Technical Information of China (English)

    Jianquan Liang; Xianji Jin; Shuidong Dai; Weiming Tong; Zhongwei Li

    2016-01-01

    Advanced metering infrastructure ( AMI) is a critical part of the smart grid, and ZigBee is playing an increasingly important role in AMI. The cyber security is the prerequisite to ensure the reliable operation of AMI. To guarantee the ZigBee communication security in AMI, a key management scheme based on the elliptic curve cryptosystem ( ECC) is proposed. According to the ways of information transformation in AMI, the scheme is categorized as unicast communication key management process and multicast communication key management process. And in the scheme, the selection of elliptic curve, the calculation of ZigBee node’ s ECC public key and private key, the establishment and distribution of the link key in unicast communication, and the establishment and distribution of the network key in multicast communication are elaborated. The analysis results show that the proposed key management scheme is secure, and consumes less memory and energy, thus, can meet the demands of communication security of AMI.

  16. Identity-based ring signature scheme based on quadratic residues

    Institute of Scientific and Technical Information of China (English)

    Xiong Hu; Qin Zhiguang; Li Fagen

    2009-01-01

    Identity-based (ID-based) ring signature has drawn great concerns in recent years and many ID-based ring signature schemes have been proposed until now. Unfortunately, all of these ID-based ring signatures are constructed from bilinear pairings, a powerful but computationally expensive primitive. Hence, ID-based ring signature without pairing is of great interest in the field of cryptography. In this paper, the authors firstly propose an ID-based ring signature scheme based on quadratic residues. The proposed scheme is proved to be existentially unforgeable against adaptive chosen message-and-identity attack under the random oracle model, assuming the hardness of factoring. The proposed scheme is more efficient than those which are constructed from bilinear pairings.

  17. DIFFERENCE SCHEMES BASING ON COEFFICIENT APPROXIMATION

    Institute of Scientific and Technical Information of China (English)

    MOU Zong-ze; LONG Yong-xing; QU Wen-xiao

    2005-01-01

    In respect of variable coefficient differential equations, the equations of coefficient function approximation were more accurate than the coefficient to be frozen as a constant in every discrete subinterval. Usually, the difference schemes constructed based on Taylor expansion approximation of the solution do not suit the solution with sharp function.Introducing into local bases to be combined with coefficient function approximation, the difference can well depict more complex physical phenomena, for example, boundary layer as well as high oscillatory, with sharp behavior. The numerical test shows the method is more effective than the traditional one.

  18. Scalable Fault-Tolerant Location Management Scheme for Mobile IP

    Directory of Open Access Journals (Sweden)

    JinHo Ahn

    2001-11-01

    Full Text Available As the number of mobile nodes registering with a network rapidly increases in Mobile IP, multiple mobility (home of foreign agents can be allocated to a network in order to improve performance and availability. Previous fault tolerant schemes (denoted by PRT schemes to mask failures of the mobility agents use passive replication techniques. However, they result in high failure-free latency during registration process if the number of mobility agents in the same network increases, and force each mobility agent to manage bindings of all the mobile nodes registering with its network. In this paper, we present a new fault-tolerant scheme (denoted by CML scheme using checkpointing and message logging techniques. The CML scheme achieves low failure-free latency even if the number of mobility agents in a network increases, and improves scalability to a large number of mobile nodes registering with each network compared with the PRT schemes. Additionally, the CML scheme allows each failed mobility agent to recover bindings of the mobile nodes registering with the mobility agent when it is repaired even if all the other mobility agents in the same network concurrently fail.

  19. Decentralising Zimbabwe’s water management: The case of Guyu-Chelesa irrigation scheme

    Science.gov (United States)

    Tambudzai, Rashirayi; Everisto, Mapedza; Gideon, Zhou

    Smallholder irrigation schemes are largely supply driven such that they exclude the beneficiaries on the management decisions and the choice of the irrigation schemes that would best suit their local needs. It is against this background that the decentralisation framework and the Dublin Principles on Integrated Water Resource Management (IWRM) emphasise the need for a participatory approach to water management. The Zimbabwean government has gone a step further in decentralising the management of irrigation schemes, that is promoting farmer managed irrigation schemes so as to ensure effective management of scarce community based land and water resources. The study set to investigate the way in which the Guyu-Chelesa irrigation scheme is managed with specific emphasis on the role of the Irrigation Management Committee (IMC), the level of accountability and the powers devolved to the IMC. Merrey’s 2008 critique of IWRM also informs this study which views irrigation as going beyond infrastructure by looking at how institutions and decision making processes play out at various levels including at the irrigation scheme level. The study was positioned on the hypothesis that ‘decentralised or autonomous irrigation management enhances the sustainability and effectiveness of irrigation schemes’. To validate or falsify the stated hypothesis, data was gathered using desk research in the form of reviewing articles, documents from within the scheme and field research in the form of questionnaire surveys, key informant interviews and field observation. The Statistical Package for Social Sciences was used to analyse data quantitatively, whilst content analysis was utilised to analyse qualitative data whereby data was analysed thematically. Comparative analysis was carried out as Guyu-Chelesa irrigation scheme was compared with other smallholder irrigation scheme’s experiences within Zimbabwe and the Sub Saharan African region at large. The findings were that whilst the

  20. Quality of service management efficient scheme for the universal mobile telecommunications system

    Directory of Open Access Journals (Sweden)

    E. Zaleta–Alejandre

    2008-04-01

    Full Text Available This research work proposes a new Radio Resource Management (RRM scheme in order to accomplish the Quality of Service (QoS management for the Universal Mobile Telecommunications System (UMTS. The solution is based on UMTS standardization and a performance evaluation is presented to demonstrate its efficiency.

  1. Optimum Efficient Mobility Management Scheme for IPv6

    Directory of Open Access Journals (Sweden)

    Virender Kumar

    2012-10-01

    Full Text Available Mobile IPv6 (MIPv6 and Hierarchical Mobile IPv6 (HMIPv6 both are the mobility management solutionsproposed by the Internet Engineering Task Force (IETF to support IP Mobility. It’s been an importantissue, that upon certain condition, out of MIPv6 and HMIPv6 which one is better. In this paper anOptimum Efficient Mobility Management (OEMM scheme is described on the basis of analytical modelwhich shows that OEMM Scheme is better in terms of performance and applicability of MIPv6 andHMIPv6. It shows that which one is better alternative between MIPv6 and HMIPv6 and if HMIPv6 isadopted it chooses the best Mobility Anchor Point (MAP. Finally it is illustrated that OEMM scheme isbetter than that of MIPv6 and HMIPv6.

  2. AN EFFICIENT BIT COMMITMENT SCHEME BASED ON FACTORING ASSUMPTION

    Institute of Scientific and Technical Information of China (English)

    Zhong Ming; Yang Yixian

    2001-01-01

    Recently, many bit commitment schemes have been presented. This paper presents a new practical bit commitment scheme based on Schnorr's one-time knowledge proof scheme,where the use of cut-and-choose method and many random exam candidates in the protocols are replaced by a single challenge number. Therefore the proposed bit commitment scheme is more efficient and practical than the previous schemes In addition, the security of the proposed scheme under factoring assumption is proved, thus the cryptographic basis of the proposed scheme is clarified.

  3. Hash function based secret sharing scheme designs

    CERN Document Server

    Chum, Chi Sing

    2011-01-01

    Secret sharing schemes create an effective method to safeguard a secret by dividing it among several participants. By using hash functions and the herding hashes technique, we first set up a (t+1, n) threshold scheme which is perfect and ideal, and then extend it to schemes for any general access structure. The schemes can be further set up as proactive or verifiable if necessary. The setup and recovery of the secret is efficient due to the fast calculation of the hash function. The proposed scheme is flexible because of the use of existing hash functions.

  4. Password Authentication Based on Fractal Coding Scheme

    Directory of Open Access Journals (Sweden)

    Nadia M. G. Al-Saidi

    2012-01-01

    Full Text Available Password authentication is a mechanism used to authenticate user identity over insecure communication channel. In this paper, a new method to improve the security of password authentication is proposed. It is based on the compression capability of the fractal image coding to provide an authorized user a secure access to registration and login process. In the proposed scheme, a hashed password string is generated and encrypted to be captured together with the user identity using text to image mechanisms. The advantage of fractal image coding is to be used to securely send the compressed image data through a nonsecured communication channel to the server. The verification of client information with the database system is achieved in the server to authenticate the legal user. The encrypted hashed password in the decoded fractal image is recognized using optical character recognition. The authentication process is performed after a successful verification of the client identity by comparing the decrypted hashed password with those which was stored in the database system. The system is analyzed and discussed from the attacker’s viewpoint. A security comparison is performed to show that the proposed scheme provides an essential security requirement, while their efficiency makes it easier to be applied alone or in hybrid with other security methods. Computer simulation and statistical analysis are presented.

  5. Secure Order-Specified Multisignature Scheme Based on DSA

    Institute of Scientific and Technical Information of China (English)

    YANG Muxiang; SU Li; LI Jun; HONG Fan

    2006-01-01

    In multisignature schemes signers can sign either in a linear order or not in any specified order, but neither of them is adequate in some scenarios where require mixture using of orderless and ordered multisignature. Most order-specified multisignatures specified the orders as linear ones. In this paper, we proposed an order-specified multisignature scheme based on DSA secure against active insider attack. To our knowledge, it is the first order-specified multisignature scheme based on DSA signature scheme, in which signers can sign in flexible order represented by series-parallel graphs. In the multisignature scheme verification to both signers and signing order are available. The security of the scheme is proved by reduce to an identification scheme that is proved have some concrete security. The running time of verifying a signature is comparable to previous schemes while the running time of multisignature generation and the space needed is less than those schemes.

  6. A Loss-Tolerant Group Key Management Scheme with Revocation Capability for Wireless Sensor Network

    Institute of Scientific and Technical Information of China (English)

    LI Lin-chun; LI Jian-hua; YI Ping; PAN Jun

    2009-01-01

    A new group key management scheme against the unreliable wireless communication channel and unsafe environment was proposed for wireless sensor network (WSN). In the proposed scheme, broadcast polynomial, generated over finite field Fq based on the secret sharing, was employed to revoke compromised sensor nodes. In order to tolerate key-update message loss, group session keys were generated as one-way hash chain sequence and distributed in advance. The analysis showes that the scheme has better performance in terms of the computation and communication overhead.

  7. Short-term incentive schemes for hospital managers

    Directory of Open Access Journals (Sweden)

    Lucas Malambe

    2013-01-01

    Full Text Available Orientation: Short-term incentives, considered to be an extrinsic motivation, are commonly used to motivate performance. This study explored hospital managers’ perceptions of short term incentives in maximising performance and retention.Research purpose: The study explored the experiences, views and perceptions of private hospital managers in South Africa regarding the use of short-term incentives to maximise performance and retention, as well as the applicability of the findings to public hospitals.Motivation for the study: Whilst there is an established link between performance reward schemes and organisational performance, there is little understanding of the effects of short term incentives on the performance and retention of hospital managers within the South African context.Research design, approach, and method: The study used a qualitative research design: interviews were conducted with a purposive sample of 19 hospital managers, and a thematic content analysis was performed.Main findings: Short-term incentives may not be the primary motivator for hospital managers, but they do play a critical role in sustaining motivation. Participants indicated that these schemes could also be applicable to public hospitals.Practical/managerial implications: Hospital managers are inclined to be more motivated by intrinsic than extrinsic factors. However, hospital managers (as middle managers also seem to be motivated by short-term incentives. A combination of intrinsic and extrinsic motivators should thus be used to maximise performance and retention.Contribution/value-add: Whilst the study sought to explore hospital managers’ perceptions of short-term incentives, it also found that an adequate balance between internal and external motivators is key to implementing an effective short-term incentive scheme.

  8. Blind Signature Scheme Based on Chebyshev Polynomials

    Directory of Open Access Journals (Sweden)

    Maheswara Rao Valluri

    2011-12-01

    Full Text Available A blind signature scheme is a cryptographic protocol to obtain a valid signature for a message from a signer such that signer’s view of the protocol can’t be linked to the resulting message signature pair. This paper presents blind signature scheme using Chebyshev polynomials. The security of the given scheme depends upon the intractability of the integer factorization problem and discrete logarithms ofChebyshev polynomials.

  9. Blind Signature Scheme Based on Chebyshev Polynomials

    OpenAIRE

    Maheswara Rao Valluri

    2011-01-01

    A blind signature scheme is a cryptographic protocol to obtain a valid signature for a message from a signer such that signer’s view of the protocol can’t be linked to the resulting message signature pair. This paper presents blind signature scheme using Chebyshev polynomials. The security of the given scheme depends upon the intractability of the integer factorization problem and discrete logarithms ofChebyshev polynomials.

  10. A weak blind signature scheme based on quantum cryptography

    Science.gov (United States)

    Wen, Xiaojun; Niu, Xiamu; Ji, Liping; Tian, Yuan

    2009-02-01

    In this paper, we present a weak blind signature scheme based on the correlation of EPR (Einstein-Padolsky-Rosen) pairs. Different from classical blind signature schemes and current quantum signature schemes, our quantum blind signature scheme could guarantee not only the unconditionally security but also the anonymity of the message owner. To achieve that, quantum key distribution and one-time pad are adopted in our scheme. Experimental analysis proved that our scheme have the characteristics of non-counterfeit, non-disavowal, blindness and traceability. It has a wide application to E-payment system, E-government, E-business, and etc.

  11. A NEW SCHEME BASED ON THE MI SCHEME AND ITS ANALYSIS

    Institute of Scientific and Technical Information of China (English)

    Jiao Luyao; Li Yifa; Qiao Shuaiting

    2013-01-01

    This article aims at designing a new Multivariate Quadratic (MQ) public-key scheme to avoid the linearization attack and differential attack against the Matsumoto-Imai (MI) scheme.Based on the original scheme,our new scheme,named the Multi-layer MI (MMI) scheme,has a structure of multi-layer central map.Firstly,this article introduces the MI scheme and describes linearization attack and differential attack; then prescribes the designation of MMI in detail,and proves that MMI can resist both linearization attack and differential attack.Besides,this article also proves that MMI can resist recent eXtended Linearization (XL)-like methods.In the end,this article concludes that MMI also maintains the efficiency of MI.

  12. Complex scheme of company image management on the stages of its life cycle

    OpenAIRE

    A.V. Kolodka

    2014-01-01

    The aim of the article. The aim of the article is to create a common integrated circuit image management during a life-cycle of enterprise based on internal and external economic conditions. The results of the analysis. In the article the general scheme of image management during a life-cycle of enterprise based on internal and external economic conditions is formed. There is no single view on the question of forming general concepts and approaches to image building. That threatens making ...

  13. A new threshold signature scheme based on fuzzy biometric identity

    Institute of Scientific and Technical Information of China (English)

    Yongquan Cai; Ke Zhang

    2009-01-01

    The focus of this paper is to present the first threshold signature scheme based on biometric identity, which is acquired from a recently proposed fuzzy identities-based encryption scheme. An important feature of this scheme, which is different from other previous ID-based threshold signature schemes, is that it can be applied to situations using not only average personal attributes in social contact but also people's noisy biometric inputs as identities. The security of our scheme in the selective-lD model reduces the limit in the hardness of the Decisional BDH Assumption.

  14. A NEW EFFICIENT ID-BASED PROXY BLIND SIGNATURE SCHEME

    Institute of Scientific and Technical Information of China (English)

    Ming Yang; Wang Yumin

    2008-01-01

    In a proxy blind signature scheme, the proxy signer is allowed to generate a blind signature on behalf of the original signer. The proxy blind signature scheme is useful in several applications such as e-voting, e-payment, etc. Recently, Zheng, et al. presented an IDentity (ID)-based proxy blind signature. In this paper, a new efficient ID-based proxy blind signature scheme from bilinear pairings is proposed, which can satisfy the security properties of both the proxy signatures and the blind signature schemes. Analysis of the scheme efficiency shows that the new scheme is more efficient than Zheng, et al.'s scheme. The proposed scheme is more practical in the real world.

  15. A Secure Key Management Scheme for Heterogeneous Secure Vehicular Communication Systems

    Institute of Scientific and Technical Information of China (English)

    SUN Zhili

    2016-01-01

    Intelligent transportation system (ITS) is proposed as the most effective way to improve road safety and traffic efficiency. However, the future of ITS for large scale transportation infrastructures deployment highly depends on the security level of vehicular commu⁃nication systems (VCS). Security applications in VCS are fulfilled through secured group broadcast. Therefore, secure key manage⁃ment schemes are considered as a critical research topic for network security. In this paper, we propose a framework for providing secure key management within heterogeneous network. The security managers (SMs) play a key role in the framework by retrieving the vehicle departure information, encapsulating block to transport keys and then executing rekeying to vehicles within the same security domain. The first part of this framework is a novel Group Key Management (GKM) scheme basing on leaving probability (LP) of vehicles to depart current VCS region. Vehicle's LP factor is introduced into GKM scheme to achieve a more efficient rekeying scheme and less rekeying costs. The second component of the framework using the blockchain concept to simplify the distributed key management in heterogeneous VCS domains. Extensive simulations and analysis are provided to show the effective⁃ness and efficiency of the proposed framework: Our GKM results demonstrate that probability⁃based BR reduces rekeying cost compared to the benchmark scheme, while the blockchain decreases the time cost of key transmission over heterogeneous net⁃works.

  16. A quantum identification scheme based on polarization modulation

    Institute of Scientific and Technical Information of China (English)

    He Guang-Qiang; Zeng Gui-Hua

    2005-01-01

    Aquantum idetification scheme including registration and identification phases is proposed.The user' passwords are transmitted by qubit string and recorded as set of quantum operators.The security of the proposed scheme is guarateed by the no-coloning theorem.Based on photon polarization modulation,an experimental approach is also designed to implement our proposed scheme.

  17. An Identity-Based Strong Designated Verifier Proxy Signature Scheme

    Institute of Scientific and Technical Information of China (English)

    WANG Qin; CAO Zhenfu

    2006-01-01

    In a strong designated verifier proxy signature scheme, a proxy signer can generate proxy signature on behalf of an original signer, but only the designated verifier can verify the validity of the proxy signature. In this paper, we first define the security requirements for strong designated verifier proxy signature schemes. And then we construct an identity-based strong designated verifier proxy signature scheme. We argue that the proposed scheme satisfies all of the security requirements.

  18. Verifiable (t, n) Threshold Signature Scheme Based on Elliptic Curve

    Institute of Scientific and Technical Information of China (English)

    WANG Hua-qun; ZHAO Jun-xi; ZHANG Li-jun

    2005-01-01

    Based on the difficulty of solving the ECDLP (elliptic curve discrete logarithm problem) on the finite field,we present a (t, n) threshold signature scheme and a verifiable key agreement scheme without trusted party. Applying a modified elliptic curve signature equation, we get a more efficient signature scheme than the existing ECDSA (elliptic curve digital signature algorithm) from the computability and security view. Our scheme has a shorter key, faster computation, and better security.

  19. A Scheme for Evaluating Feral Horse Management Strategies

    Directory of Open Access Journals (Sweden)

    L. L. Eberhardt

    2012-01-01

    Full Text Available Context. Feral horses are an increasing problem in many countries and are popular with the public, making management difficult. Aims. To develop a scheme useful in planning management strategies. Methods. A model is developed and applied to four different feral horse herds, three of which have been quite accurately counted over the years. Key Results. The selected model has been tested on a variety of data sets, with emphasis on the four sets of feral horse data. An alternative, nonparametric model is used to check the selected parametric approach. Conclusions. A density-dependent response was observed in all 4 herds, even though only 8 observations were available in each case. Consistency in the model fits suggests that small starting herds can be used to test various management techniques. Implications. Management methods can be tested on actual, confined populations.

  20. A New Efficient Certificate-Based Signature Scheme

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yichen; LI Jiguo; WANG Zhiwei; YAO Wei

    2015-01-01

    Certificate-based cryptography is a new kind of public key algorithm, which combines the merits of traditional Public key infrastructure (PKI) and identity-based cryptography. It removes the inherent key escrow problem in the identity-based cryptography and eliminates the certificate revocation problem and third-party queries in the traditional PKI. In this paper, we propose an effi-cient certificate-based signature scheme based on bilinear pairings. Under the strong security model of certificate-based signature scheme, we prove that our scheme is exis-tentially unforgeable against adaptive chosen message and identity attacks in the random oracle. In our scheme, only two pairing operations are needed in the signing and ver-ification processes. Compared with some certificate-based signature schemes from bilinear pairings, our scheme en-joys more advantage in computational cost and communi-cational cost.

  1. Threshold Signature Scheme Based on Discrete Logarithm and Quadratic Residue

    Institute of Scientific and Technical Information of China (English)

    FEI Ru-chun; WANG Li-na

    2004-01-01

    Digital signature scheme is a very important research field in computer security and modern cryptography.A(k,n) threshold digital signature scheme is proposed by integrating digital signature scheme with Shamir secret sharing scheme.It can realize group-oriented digital signature, and its security is based on the difficulty in computing discrete logarithm and quadratic residue on some special conditions.In this scheme, effective digital signature can not be generated by any k-1 or fewer legal users, or only by signature executive.In addition, this scheme can identify any legal user who presents incorrect partial digital signature to disrupt correct signature, or any illegal user who forges digital signature.A method of extending this scheme to an Abelian group such as elliptical curve group is also discussed.The extended scheme can provide rapider computing speed and stronger security in the case of using shorter key.

  2. An improved identity-based proxy ring signature scheme

    Institute of Scientific and Technical Information of China (English)

    Lang Weimin; Yang Zongkai; Cheng Wenqing; Tan Yunmeng

    2005-01-01

    Proxy ring signature schemes have been shown to be useful in various applications, such as electronic polling, electronic payment, etc. In this paper, we point out that Lang's scheme is unreasonable and propose an improved Identity-based proxy ring scheme from bilinear pairings which is reasonable and overcomes the deficiencies of Lang's scheme. Our scheme can prevent the original signer from generating the proxy ring signature, thus the profits of the proxy signer are guaranteed. In addition, our scheme satisfies all the security requirements of proxy ring signature, I.e. Signer-ambiguity, non-forgeability, verification, non-deniability and distinguishability. As compared with Zhang's scheme, our scheme is a computational efficiency improvement for signature verification because the computational cost of bilinear pairings required is reduced from O(n) to O(1).

  3. Broadcast encryption schemes based on RSA

    Institute of Scientific and Technical Information of China (English)

    MU Ning-bo; HU Yu-pu; OU Hai-wen

    2009-01-01

    Three broadcast schemes for small receiver set using the property of RSA modulus are presented. They can solve the problem of data redundancy when the size of receiver set is small. In the proposed schemes, the center uses one key to encrypt the message and can revoke authorization conveniently. Every authorized user only needs to store one decryption key of a constant size. Among these three schemes, the first one has indistinguishability against adaptive chosen ciphertext attack (IND-CCA2) secure, and any collusion of authorized users cannot produce a new decryption key but the sizes of encryption modulus and ciphertext are linear in the number of receivers. In the second scheme, the size of ciphertext is half of the first one and any two authorized users can produce a new decryption key, but the center can identify them using the traitor tracing algorithm. The third one is the most efficient but the center cannot identify the traitors exactly.

  4. The Performance-based Funding Scheme of Universities

    Directory of Open Access Journals (Sweden)

    Juha KETTUNEN

    2016-05-01

    Full Text Available The purpose of this study is to analyse the effectiveness of the performance-based funding scheme of the Finnish universities that was adopted at the beginning of 2013. The political decision-makers expect that the funding scheme will create incentives for the universities to improve performance, but these funding schemes have largely failed in many other countries, primarily because public funding is only a small share of the total funding of universities. This study is interesting because Finnish universities have no tuition fees, unlike in many other countries, and the state allocates funding based on the objectives achieved. The empirical evidence of the graduation rates indicates that graduation rates increased when a new scheme was adopted, especially among male students, who have more room for improvement than female students. The new performance-based funding scheme allocates the funding according to the output-based indicators and limits the scope of strategic planning and the autonomy of the university. The performance-based funding scheme is transformed to the strategy map of the balanced scorecard. The new funding scheme steers universities in many respects but leaves the research and teaching skills to the discretion of the universities. The new scheme has also diminished the importance of the performance agreements between the university and the Ministry. The scheme increases the incentives for universities to improve the processes and structures in order to attain as much public funding as possible. It is optimal for the central administration of the university to allocate resources to faculties and other organisational units following the criteria of the performance-based funding scheme. The new funding scheme has made the universities compete with each other, because the total funding to the universities is allocated to each university according to the funding scheme. There is a tendency that the funding schemes are occasionally

  5. Hybrid FPMS: A New Fairness Protocol Management Scheme for Community Wireless Mesh Networks

    CERN Document Server

    Widanapathirana, Chathuranga; Goi, Bok-Min

    2012-01-01

    Node cooperation during packet forwarding operations is critically important for fair resource utilization in Community Wireless Mesh Networks (CoWMNs). In a CoWMN, node cooperation is achieved by using fairness protocols specifically designed to detect and isolate malicious nodes, discourage unfair behavior, and encourage node participation in forwarding packets. In general, these protocols can be split into two groups: Incentive-based ones, which are managed centrally, and use credit allocation schemes. In contrast, reputation-based protocols that are decentralized, and rely on information exchange among neighboring nodes. Centrally managed protocols inevitably suffer from scalability problems. The decentralized, reputation-based protocols lacks in detection capability, suffer from false detections and error propagation compared to the centralized, incentive-based protocols. In this study, we present a new fairness protocol management scheme, called Hybrid FPMS that captures the superior detection capabilit...

  6. A Cross-Layer Key Management Scheme for MIPv6 Fast Handover over IEEE 802.11 Wireless LAN

    Directory of Open Access Journals (Sweden)

    Chang-Seop Park

    2015-01-01

    Full Text Available A new key management and security scheme is proposed to integrate Layer Two (L2 and Layer Three (L3 keys for secure and fast Mobile IPv6 handover over IEEE 802.11 Wireless Local Area Network (WLAN. Unlike the original IEEE 802.11-based Mobile IPv6 Fast Handover (FMIPv6 that requires time-consuming IEEE 802.1x-based Extensible Authentication Protocol (EAP authentication on each L3 handover, the newly proposed key management and security scheme requires only one 802.1x-EAP regardless of how many L3 handovers occur. Therefore, the proposed scheme reduces the handover latency that results from a lengthy 802.1x-based EAP. The proposed key management and security scheme is extensively analyzed in terms of security and performance, and the proposed security scheme is shown to be more secure than those that were previously proposed.

  7. Adaptive Image Transmission Scheme over Wavelet-Based OFDM System

    Institute of Scientific and Technical Information of China (English)

    GAOXinying; YUANDongfeng; ZHANGHaixia

    2005-01-01

    In this paper an adaptive image transmission scheme is proposed over Wavelet-based OFDM (WOFDM) system with Unequal error protection (UEP) by the design of non-uniform signal constellation in MLC. Two different data division schemes: byte-based and bitbased, are analyzed and compared. Different bits are protected unequally according to their different contribution to the image quality in bit-based data division scheme, which causes UEP combined with this scheme more powerful than that with byte-based scheme. Simulation results demonstrate that image transmission by UEP with bit-based data division scheme presents much higher PSNR values and surprisingly better image quality. Furthermore, by considering the tradeoff of complexity and BER performance, Haar wavelet with the shortest compactly supported filter length is the most suitable one among orthogonal Daubechies wavelet series in our proposed system.

  8. Third-order modified coefficient scheme based on essentially non-oscillatory scheme

    Institute of Scientific and Technical Information of China (English)

    LI Ming-jun; YANG Yu-yue; SHU Shi

    2008-01-01

    A third-order numerical scheme is presented to give approximate solutions to multi-dimensional hyperbolic conservation laws only using modified coefficients of an essentially non-oscillatory (MCENO) scheme without increasing the base points during construction of the scheme.The construction process shows that the modified coefficient approach preserves favourable properties inherent in the original essentially non oscillatory (ENO) scheme for its essential non-oscillation,total variation bounded (TVB),etc.The new scheme improves accuracy by one order compared to the original one.The proposed MCENO scheme is applied to simulate two-dimensional Rayleigh-Taylor (RT) instability with densities 1:3 and 1:100,and solve the Lax shock-wave tube numerically.The ratio of CPU time used to implement MCENO,the third-order ENO and fifth-order weighed ENO (WENO) schemes is 0.62:1:2.19.This indicates that MCENO improves accuracy in smooth regions and has higher accuracy and better efficiency compared to the original ENO scheme.

  9. An Improved Scalar Costa Scheme Based on Watson Perceptual Model

    Institute of Scientific and Technical Information of China (English)

    QI Kai-yue; CHEN Jian-bo; ZHOU Yi

    2008-01-01

    An improved scalar Costa scheme (SCS) was proposed by using improved Watson perceptual model to adaptively decide quantization step size and scaling factor. The improved scheme equals to embed hiding data based on an actual image. In order to withstand amplitude scaling attack, the Watson perceptual model was redefined, and the improved scheme using the new definition can insure quantization step size in decoder that is proportional to amplitude scaling attack factor. The performance of the improved scheme outperforms that of SCS with fixed quantization step size. The improved scheme combines information theory and visual model.

  10. A Proxy Blind Signature Scheme Based on ECDLP

    Institute of Scientific and Technical Information of China (English)

    WANGHaiyan; WANGRuchuan

    2005-01-01

    While proxy signature scheme enables an original signer to fully authorize a proxy to sign a message on his or her behalf legally and undeniably, blind signature scheme keeps the message blind from the signer so that the signer cannot make a linkage between the signature and the identity of requester (receiver). Both schemes have been widely applied in the electronic business. A new ECDLP (Elliptic curve discrete problem)-based proxy blind signature scheme is to be proposed in this paper by integrating the security properties of both schemes.

  11. Quantum election scheme based on anonymous quantum key distribution

    Institute of Scientific and Technical Information of China (English)

    Zhou Rui-Rui; Yang Li

    2012-01-01

    An unconditionally secure authority-certified anonymous quantum key distribution scheme using conjugate coding is presented,based on which we construct a quantum election scheme without the help of an entanglement state.We show that this election scheme ensures the completeness,soundness,privacy,eligibility,unreusability,fairness,and verifiability of a large-scale election in which the administrator and counter are semi-honest.This election scheme can work even if there exist loss and errors in quantum channels.In addition,any irregularity in this scheme is sensible.

  12. Design Scheme of Remote Monitoring System Based on Qt

    Directory of Open Access Journals (Sweden)

    Xu Dawei

    2015-01-01

    Full Text Available This paper introduces a design scheme of remote monitoring system based on Qt, the scheme of remote monitoring system based on S3C2410 and Qt, with the aid of cross platform development tools Qt and powerful ARM platform design and implementation. The development of remote video surveillance system based on embedded terminal has practical significance and value.

  13. An Encoder/Decoder Scheme of OCDMA Based on Waveguide

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A new encoder/decoder scheme of OCDMA based on waveguide isproposed in this paper. The principle as well as the structure of waveguide encoder/decoder is given. It can be seen that all-optical OCDMA encoder/decoder can be realized by the proposed scheme of the waveguide encoder/decoder. It can also make the OCDMA encoder/decoder integrated easily and the access controlled easily. The system based on this scheme can work under the entirely asynchronous condition.

  14. Cost-based droop scheme with lower generation costs for microgrids

    DEFF Research Database (Denmark)

    Nutkani, I. U.; Loh, Poh Chiang; Blaabjerg, Frede

    2013-01-01

    In an autonomous microgrid where centralized management and communication links are not viable, droop control has been the preferred scheme for power sharing among distributed generators (DGs). At present, although many droop variations have been proposed to achieve proportional power sharing based...... on the DG kVA ratings. Other operating characteristics like generation costs, efficiencies and emission penalties at different loadings have not been considered. This makes existing droop schemes not too well-suited for standalone microgrids without central management system, where different types of DGs...... usually exist. As an alternative, this paper proposes a cost-based droop scheme, whose objective is to reduce a generation cost realized with various DG operating characteristics taken into consideration. The proposed droop scheme therefore retains all advantages of the traditional droop schemes, while...

  15. Evaluation of Rehabilitation Strategies and Management Schemes for the Improvement of Mangrove Management Programs in Lingayen Gulf

    Directory of Open Access Journals (Sweden)

    Severino Salmo III

    2007-06-01

    Full Text Available We evaluated the mangrove rehabilitation strategies and management schemes in five municipalities in Lingayen Gulf (Bolinao, Anda, Bani, Alaminos and San Fernando. Mangrove planting appears to be the first and only option used in the area, ignoring other recommended management strategies, e.g. conservation, landscaping, and sustainable production. All planting sites were located in coastal fringes and are mostly monospeficic stands of the species Rhizophora mucronata. The planted mangroves were constrained by low seedling survival and stunted growth as probably caused by poor species-substrate matching, mono-species planting and pest infestations. Three management schemes were noted: community-managed (Bolinao and Anda, local government unit (LGU-managed (Alaminos and San Fernando, and co-managed between the LGU and the community (Bani. The community-managed mangrove areas have the benefits of voluntary efforts from community-based organizations in conducting daily management activities but were constrained with budgetary and logistical concerns. In contrast, both LGU-managed and co-managed areas received institutional and logistical supports from their respective municipal governments, but lacking community participation made mangrove management difficult. Almost two decades of mangrove management indeed helped improved the mangrove forest condition, at least in terms of forest structure. These projects demonstrated some level of success but also encountered several setbacks. Several lessons can be derived from these areas that can help improve the mangrove rehabilitation and management approaches in Lingayen Gulf. Among the recommendations are: (1 provide ordinance enacting the remaining natural secondary growth mangroves as marine protected areas, (2 promote planting in former mangrove areas by reverting abandoned, idled and unproductive aquaculture ponds to mangroves; (3 improve management schemes by formulating resource management plan

  16. An effective and secure key-management scheme for hierarchical access control in E-medicine system.

    Science.gov (United States)

    Odelu, Vanga; Das, Ashok Kumar; Goswami, Adrijit

    2013-04-01

    Recently several hierarchical access control schemes are proposed in the literature to provide security of e-medicine systems. However, most of them are either insecure against 'man-in-the-middle attack' or they require high storage and computational overheads. Wu and Chen proposed a key management method to solve dynamic access control problems in a user hierarchy based on hybrid cryptosystem. Though their scheme improves computational efficiency over Nikooghadam et al.'s approach, it suffers from large storage space for public parameters in public domain and computational inefficiency due to costly elliptic curve point multiplication. Recently, Nikooghadam and Zakerolhosseini showed that Wu-Chen's scheme is vulnerable to man-in-the-middle attack. In order to remedy this security weakness in Wu-Chen's scheme, they proposed a secure scheme which is again based on ECC (elliptic curve cryptography) and efficient one-way hash function. However, their scheme incurs huge computational cost for providing verification of public information in the public domain as their scheme uses ECC digital signature which is costly when compared to symmetric-key cryptosystem. In this paper, we propose an effective access control scheme in user hierarchy which is only based on symmetric-key cryptosystem and efficient one-way hash function. We show that our scheme reduces significantly the storage space for both public and private domains, and computational complexity when compared to Wu-Chen's scheme, Nikooghadam-Zakerolhosseini's scheme, and other related schemes. Through the informal and formal security analysis, we further show that our scheme is secure against different attacks and also man-in-the-middle attack. Moreover, dynamic access control problems in our scheme are also solved efficiently compared to other related schemes, making our scheme is much suitable for practical applications of e-medicine systems.

  17. A Dynamic ID-based Remote User Authentication Scheme

    CERN Document Server

    Das, Manik Lal; Gulati, Ved P

    2004-01-01

    Password-based authentication schemes are the most widely used techniques for remote user authentication. Many static ID-based remote user authentication schemes both with and without smart cards have been proposed. Most of the schemes do not allow the users to choose and change their passwords, and maintain a verifier table to verify the validity of the user login. In this paper we present a dynamic ID-based remote user authentication scheme using smart cards. Our scheme allows the users to choose and change their passwords freely, and do not maintain any verifier table. The scheme is secure against ID-theft, and can resist the reply attacks, forgery attacks, guessing attacks, insider attacks and stolen verifier attacks.

  18. Crab biodiversity under different management schemes of mangrove ecosystems

    Directory of Open Access Journals (Sweden)

    M. Bandibas

    2016-01-01

    Full Text Available Reforestation is one of the Philippines’ government efforts to restore and rehabilitate degraded mangrove ecosystems. Although there is recovery of the ecosystem in terms of vegetation, the recovery of closely-linked faunal species in terms of community structure is still understudied. This research investigates the community structure of mangrove crabs under two different management schemes: protected mangroves and reforested mangroves. The transect-plot method was employed in each management scheme to quantify the vegetation, crab assemblages and environmental variables. Community composition of crabs and mangrove trees were compared between protected and reforested mangroves using non-metric multi-dimensional scaling and analysis of similarity in PRIMER 6. Chi-squared was used to test the variance of sex ration of the crabs. Canonical Correspondence Analysis was used to determine the relationship between crabs and environmental parameters. A total of twelve species of crabs belonging to six families were identified in protected mangroves while only four species were documented in reforested mangroves. Perisesarma indiarum and Baptozius vinosus were the most dominant species in protected and reforested mangrove, respectively.  Univariate analysis of variance of crab assemblage data revealed significant differences in crab composition and abundance between protected mangroves and from reforested mangroves (P

  19. A Digital Signature Scheme Based on MST3 Cryptosystems

    Directory of Open Access Journals (Sweden)

    Haibo Hong

    2014-01-01

    Full Text Available As special types of factorization of finite groups, logarithmic signature and cover have been used as the main components of cryptographic keys for secret key cryptosystems such as PGM and public key cryptosystems like MST1, MST2, and MST3. Recently, Svaba et. al proposed a revised MST3 encryption scheme with greater security. Meanwhile, they put forward an idea of constructing signature schemes on the basis of logarithmic signatures and random covers. In this paper, we firstly design a secure digital signature scheme based on logarithmic signatures and random covers. In order to complete the task, we devise a new encryption scheme based on MST3 cryptosystems.

  20. Improved ID-Based Signature Scheme Solving Key Escrow

    Institute of Scientific and Technical Information of China (English)

    LIAO Jian; QI Ying-hao; HUANG Pei-wei; RONG Men-tian; LI Sheng-hong

    2006-01-01

    Key escrow is an inherent disadvantage for traditional ID-based cryptosystem, i.e. , the dishonest private key generator (PKG) can forge the signature of any user, meanwhile, the user can deny the signature actually signed by him/herself. To avoid the keyescrow problem, an ID-based signature scheme was presented without trusted PKG. The exact proof of security was presented to demonstrate that our scheme is secure against existential forgery on adaptively chosen message and ID attacks assuming the complexity of computational Diffie-Hellman(CDH) problem. Compared with other signature schemes, the proposed scheme is more efficient.

  1. Cost-based droop scheme for DC microgrid

    DEFF Research Database (Denmark)

    Nutkani, Inam Ullah; Wang, Peng; Loh, Poh Chiang

    2014-01-01

    voltage level, less on optimized operation and control of generation sources. The latter theme is perused in this paper, where cost-based droop scheme is proposed for distributed generators (DGs) in DC microgrids. Unlike traditional proportional power sharing based droop scheme, the proposed scheme...... considers the generation costs of DGs and dynamically tunes their droop gradients to produce more power from less costly DGs and vice versa. The proposed scheme is fully autonomous, simple to implement in dispatchable and non-dispatchable sources coupled with storage, support islanded and grid......-connected operation. Most importantly, the proposed scheme can reduce overall total generation cost in DC microgrids without centralized controller and communication links. The performance of the proposed scheme has been verified under different load conditions....

  2. A general risk-based adaptive management scheme incorporating the Bayesian Network Relative Risk Model with the South River, Virginia, as case study.

    Science.gov (United States)

    Landis, Wayne G; Markiewicz, April J; Ayre, Kim K; Johns, Annie F; Harris, Meagan J; Stinson, Jonah M; Summers, Heather M

    2017-01-01

    Adaptive management has been presented as a method for the remediation, restoration, and protection of ecological systems. Recent reviews have found that the implementation of adaptive management has been unsuccessful in many instances. We present a modification of the model first formulated by Wyant and colleagues that puts ecological risk assessment into a central role in the adaptive management process. This construction has 3 overarching segments. Public engagement and governance determine the goals of society by identifying endpoints and specifying constraints such as costs. The research, engineering, risk assessment, and management section contains the decision loop estimating risk, evaluating options, specifying the monitoring program, and incorporating the data to re-evaluate risk. The 3rd component is the recognition that risk and public engagement can be altered by various externalities such as climate change, economics, technological developments, and population growth. We use the South River, Virginia, USA, study area and our previous research to illustrate each of these components. In our example, we use the Bayesian Network Relative Risk Model to estimate risks, evaluate remediation options, and provide lists of monitoring priorities. The research, engineering, risk assessment, and management loop also provides a structure in which data and the records of what worked and what did not, the learning process, can be stored. The learning process is a central part of adaptive management. We conclude that risk assessment can and should become an integral part of the adaptive management process. Integr Environ Assess Manag 2017;13:115-126. © 2016 SETAC.

  3. CONTROL SCHEMES FOR CMAC NEURAL NETWORK-BASED VISUAL SERVOING

    Institute of Scientific and Technical Information of China (English)

    Wang Huaming; Xi Wenming; Zhu Jianying

    2003-01-01

    In IBVS (image based visual servoing), the error signal in image space should be transformed into the control signal in the input space quickly. To avoid the iterative adjustment and complicated inverse solution of image Jacobian, CMAC (cerebellar model articulation controller) neural network is inserted into visual servo control loop to implement the nonlinear mapping. Two control schemes are used. Simulation results on two schemes are provided, which show a better tracking precision and stability can be achieved using scheme 2.

  4. Efficient Identity Based Public Verifiable Signcryption Scheme

    OpenAIRE

    Kushwah, Prashant; Lal, Sunder

    2011-01-01

    Signcryption is a cryptographic primitive which performs encryption and signature in a single logical step. In conventional signcryption only receiver of the signcrypted text can verify the authenticity of the origin i.e. signature of the sender on the message after decrypting the cipher text. In public verifiable signcryption scheme anyone can verify the authenticity of the origin who can access the signcrypted text i.e. signature of the sender on the cipher text. Public verifiable signcrypt...

  5. Cost Based Droop Schemes for Economic Dispatch in Islanded Microgrids

    DEFF Research Database (Denmark)

    Chen, Feixiong; Chen, Minyou; Li, Qiang

    2017-01-01

    In this paper, cost based droop schemes are proposed, to minimize the total active power generation cost in an islanded microgrid (MG), while the simplicity and decentralized nature of the droop control are retained. In cost based droop schemes, the incremental costs of distributed generators (DGs......) are embedded into the droop schemes, where the incremental cost is a derivative of the DG cost function with respect to output power. In the steady state, DGs share a single common frequency, and cost based droop schemes equate incremental costs of DGs, thus minimizing the total active power generation cost......, in terms of the equal incremental cost principle. Finally, simulation results in an islanded MG with high penetration of intermittent renewable energy sources are presented, to demonstrate the eectiveness, as well as plug and play capability of the cost based droop schemes....

  6. MIXED SCHEME FOR IMAGE EDGE DETECTION BASED ON WAVELET TRANSFORM

    Institute of Scientific and Technical Information of China (English)

    Xie Hongmei; Yu Bianzhang; Zhao Jian

    2004-01-01

    A mixed scheme based on Wavelet Transformation (WT) is proposed for image edge detection. The scheme combines the wavelet transform and traditional Sobel and LoG (Laplacian of Gaussian) operator edge-detection algorithms. The precise theory analysis is given to show that the wavelet transformation has an advantage for signal processing. Simulation results show that the new scheme is better than only using the Sobel or LoG methods. Complexity analysis is also given and the conclusion is acceptable, therefore the proposed scheme is effective for edge detection.

  7. A novel chaotic encryption scheme based on pseudorandom bit padding

    CERN Document Server

    Sadra, Yaser; Fard, Zahra Arasteh

    2012-01-01

    Cryptography is always very important in data origin authentications, entity authentication, data integrity and confidentiality. In recent years, a variety of chaotic cryptographic schemes have been proposed. These schemes has typical structure which performed the permutation and the diffusion stages, alternatively. The random number generators are intransitive in cryptographic schemes and be used in the diffusion functions of the image encryption for diffused pixels of plain image. In this paper, we propose a chaotic encryption scheme based on pseudorandom bit padding that the bits be generated by a novel logistic pseudorandom image algorithm. To evaluate the security of the cipher image of this scheme, the key space analysis, the correlation of two adjacent pixels and differential attack were performed. This scheme tries to improve the problem of failure of encryption such as small key space and level of security.

  8. A scalable admission control scheme based on time label

    Institute of Scientific and Technical Information of China (English)

    杨松岸; 杨华; 杨宇航

    2004-01-01

    Resource reservation protocols allow communicating hosts to reserve resources such as bandwidth to offer guaranteed service. However, current resource reservation architectures do not scale well for a large number of flows. In this paper, we present a simple reservation protocol and a scalable admission control algorithm, which can provide QoS guarantees to individual flows without per-flow management in the network core. By mapping each flow to a definite time, this scheme addresses the problems that limit the effectiveness of current endpoint admission control schemes. The overall admission control process is described. Analysis is used to explain the reasonability of our scheme and simulation validates its performance.

  9. Comparison of two SVD-based color image compression schemes.

    Science.gov (United States)

    Li, Ying; Wei, Musheng; Zhang, Fengxia; Zhao, Jianli

    2017-01-01

    Color image compression is a commonly used process to represent image data as few bits as possible, which removes redundancy in the data while maintaining an appropriate level of quality for the user. Color image compression algorithms based on quaternion are very common in recent years. In this paper, we propose a color image compression scheme, based on the real SVD, named real compression scheme. First, we form a new real rectangular matrix C according to the red, green and blue components of the original color image and perform the real SVD for C. Then we select several largest singular values and the corresponding vectors in the left and right unitary matrices to compress the color image. We compare the real compression scheme with quaternion compression scheme by performing quaternion SVD using the real structure-preserving algorithm. We compare the two schemes in terms of operation amount, assignment number, operation speed, PSNR and CR. The experimental results show that with the same numbers of selected singular values, the real compression scheme offers higher CR, much less operation time, but a little bit smaller PSNR than the quaternion compression scheme. When these two schemes have the same CR, the real compression scheme shows more prominent advantages both on the operation time and PSNR.

  10. Ciphertext-Policy Attribute-Based Broadcast Encryption Scheme

    NARCIS (Netherlands)

    Asim, Muhammad; Ibraimi, Luan; Petkovic, Milan

    2011-01-01

    In this work, we design a new attribute-based encryption scheme with the revocation capability. In the proposed schemes, the user (broadcaster) encrypts the data according to an access policy over the set of attributes, and a list of the identities of revoked users. Only recipients who have attribut

  11. A FRACTAL-BASED STOCHASTIC INTERPOLATION SCHEME IN SUBSURFACE HYDROLOGY

    Science.gov (United States)

    The need for a realistic and rational method for interpolating sparse data sets is widespread. Real porosity and hydraulic conductivity data do not vary smoothly over space, so an interpolation scheme that preserves irregularity is desirable. Such a scheme based on the properties...

  12. PILOT-BASED FREQUENCY OFFSET DETECTION SCHEME IN OFDM SYSTEM

    Institute of Scientific and Technical Information of China (English)

    Du Zheng; Zhu Jinkang

    2003-01-01

    The frequency offset information is extracted from local pilot amplitude characteristics, which suffer much less distortion in frequency-selective fading channels than those utilizing frequency domain correlation techniques. Simulation shows that the performance of this scheme has better performance than the existing frequency domain pilot-based frequency offset detection scheme.

  13. Two-level information management scheme based on visual cryptography and QR code%基于视觉密码和QR码的两级信息管理方案

    Institute of Scientific and Technical Information of China (English)

    刘莺迎; 付正欣; 王益伟

    2016-01-01

    设计了一种新的扩展多秘密视觉密码,能够分享n个公开信息和n-1个隐私信息,其像素扩展度为4且相对差为1/4。在此基础上,结合QR码提出了一种两级信息管理方案,其中一般参与者的共享份可以呈现参与者公开信息的QR码,而且管理者的共享份与一般共享份叠加后,可以呈现参与者隐私信息的QR码。实验结果表明,公开信息和隐私信息的QR码尽管存在失真,仍可以被正确识别。%This paper designed a new extended multi-secret visual cryptography scheme (EMVCS),which could share n pub-lic information and n-1 private information.The pixel expansion of EMVCS was 4,and the relative difference was 1/4.Fur-thermore,it proposed a new two-level information management scheme based on EMVCS and QR code,in which the common participants’shares could display public information QR code.Meanwhile,the private information QR code of common partici-pants would be shown by stacking the share of manager and common participant.The experimental results demonstrate that the distorted QR codes of public and private information can be recognized correctly.

  14. Distributed Mobility Management Scheme for Mobile IPv6

    Science.gov (United States)

    Wakikawa, Ryuji; Valadon, Guillaume; Shigechika, Noriyuki; Murai, Jun

    Mobile IPv6 and Network Mobility (NEMO) have been standardized as IP extensions. While these technologies are planned to be adopted by several communities, such as the vehicle, aviation, and cellular industries, Mobile IPv6 has serious deployment issues such as scalability, protocol resilience, and redundancy. In these technologies, a special router called a home agent is introduced to support the movement of mobile nodes. This home agent introduces overlapping, inefficient routes, and becomes a single point of failure and a performance bottleneck. In this paper, a new concept for scalable and dependable mobility management scheme is proposed. Multiple home agents serve the same set of mobile nodes. The Home Agent Reliability protocol and Home Agent migration are introduced to achieve this concept. We also propose an overlay network named a Global Mobile eXchange (GMX) that efficiently handles data traffic from and to mobile nodes, and operates home agents as would an Internet eXchange Point (IXP).

  15. Study on livestock management scheme considering national environmental capacity

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jee Yong; Shin, Eun Seong [Korea Environment Institute, Seoul (Korea)

    1999-12-01

    In 'Our Common Future' reported in WCED (World Commission on Environment and Development) in 1983, a sustainable development is defined as 'development that meets the needs of the present without compromising the ability of future generations to meet their own needs'. The environmental problem since the 1992 Rio Summit has focused on sustainability. Furthermore agriculture industry also promotes a sustainable agriculture in worldwide. The most focused one among sustainable agriculture is an environmental friendly agriculture including organic agriculture since soil has been acidified due to the abuse of chemical fertilizer for mass production. In this study, it represents an appropriate management scheme for livestock suitable to Korean land by assessing admitted capacity and water quality pollution. 32 refs., 11 figs., 77 tabs.

  16. Risk management assessment of Health Maintenance Organisations participating in the National Health Insurance Scheme

    Science.gov (United States)

    Campbell, Princess Christina; Korie, Patrick Chukwuemeka; Nnaji, Feziechukwu Collins

    2014-01-01

    Background: The National Health Insurance Scheme (NHIS), operated majorly in Nigeria by health maintenance organisations (HMOs), took off formally in June 2005. In view of the inherent risks in the operation of any social health insurance, it is necessary to efficiently manage these risks for sustainability of the scheme. Consequently the risk-management strategies deployed by HMOs need regular assessment. This study assessed the risk management in the Nigeria social health insurance scheme among HMOs. Materials and Methods: Cross-sectional survey of 33 HMOs participating in the NHIS. Results: Utilisation of standard risk-management strategies by the HMOs was 11 (52.6%). The other risk-management strategies not utilised in the NHIS 10 (47.4%) were risk equalisation and reinsurance. As high as 11 (52.4%) of participating HMOs had a weak enrollee base (less than 30,000 and poor monthly premium and these impacted negatively on the HMOs such that a large percentage 12 (54.1%) were unable to meet up with their financial obligations. Most of the HMOs 15 (71.4%) participated in the Millennium development goal (MDG) maternal and child health insurance programme. Conclusions: Weak enrollee base and poor monthly premium predisposed the HMOs to financial risk which impacted negatively on the overall performance in service delivery in the NHIS, further worsened by the non-utilisation of risk equalisation and reinsurance as risk-management strategies in the NHIS. There is need to make the scheme compulsory and introduce risk equalisation and reinsurance. PMID:25298605

  17. Risk management assessment of Health Maintenance Organisations participating in the National Health Insurance Scheme

    Directory of Open Access Journals (Sweden)

    Princess Christina Campbell

    2014-01-01

    Full Text Available Background: The National Health Insurance Scheme (NHIS, operated majorly in Nigeria by health maintenance organisations (HMOs, took off formally in June 2005. In view of the inherent risks in the operation of any social health insurance, it is necessary to efficiently manage these risks for sustainability of the scheme. Consequently the risk-management strategies deployed by HMOs need regular assessment. This study assessed the risk management in the Nigeria social health insurance scheme among HMOs. Materials and Methods: Cross-sectional survey of 33 HMOs participating in the NHIS. Results: Utilisation of standard risk-management strategies by the HMOs was 11 (52.6%. The other risk-management strategies not utilised in the NHIS 10 (47.4% were risk equalisation and reinsurance. As high as 11 (52.4% of participating HMOs had a weak enrollee base (less than 30,000 and poor monthly premium and these impacted negatively on the HMOs such that a large percentage 12 (54.1% were unable to meet up with their financial obligations. Most of the HMOs 15 (71.4% participated in the Millennium development goal (MDG maternal and child health insurance programme. Conclusions: Weak enrollee base and poor monthly premium predisposed the HMOs to financial risk which impacted negatively on the overall performance in service delivery in the NHIS, further worsened by the non-utilisation of risk equalisation and reinsurance as risk-management strategies in the NHIS. There is need to make the scheme compulsory and introduce risk equalisation and reinsurance.

  18. Identity-based threshold signature and mediated proxy signature schemes

    Institute of Scientific and Technical Information of China (English)

    YU Yong; YANG Bo; SUN Ying

    2007-01-01

    Proxy signature schemes allow an original signer to delegate his signing rights to a proxy signer. However, many proxy signature schemes have the defect which is the inability to solve the proxy revocation problem. In this article, we firstly propose an identity-based threshold signature scheme and show that it has the properties of unforgeability and robustness. In our threshold signature scheme, we adopt such a method that the private key associated with an identity rather than the master key is shared. Then, based on the threshold signature scheme, an identity-based mediated proxy signature scheme is proposed where a security mediator (SEM) is introduced to help a proxy signer to generate valid proxy signatures, examine whether a proxy signer signs according to the warrant, and check the revocation of a proxy signer. It is shown that the proposed scheme satisfies all the security requirements of a secure proxy signature. Moreover, a proxy signer must cooperate with the SEM to generate a valid proxy signature, which makes the new scheme have an effective and fast proxy revocation.

  19. Improved RB-HARQ scheme based on structured LDPC codes

    Institute of Scientific and Technical Information of China (English)

    WANG Wen-jun; LIN Yue-wei; YAN Yuan

    2007-01-01

    Reliability-based hybrid automatic repeat request (ARQ) (RB-HARQ) is a recently introduced approach to incremental-redundancy ARQ. In RB-HARQ scheme, the bits that are to be retransmitted are adaptively selected at the receiver based on the estimated bit reliability. It could result in significant performance gain but requires huge overhead in the feedback channel. In this study, an improved RB-HARQ scheme (IRB-HARQ) for structured low-density parity-check codes is proposed, which simplifies the comparison operations needed to search the bits to be retransmitted and outperforms the RB-HARQ scheme in consideration of the bit transmission power for the requesting messages on the feedback link. Simulation results show that the IRB-HARQ scheme is more efficient and practical than the RB-HARQ scheme.

  20. Key-management Scheme Based on IBC for Clustering Wireless Sensor Network%基于 IBC的无线传感器网络层簇式密钥管理方案*

    Institute of Scientific and Technical Information of China (English)

    李政; 魏国珩

    2014-01-01

    密钥管理是无线传感器网络中关键安全技术之一。无线传感器网络的密钥管理由于布置位置、计算量有限、存储能力有限,使得设计面临许多挑战。在分析无线传感器网络安全需求的基础上,针对无线传感器网络密钥管理问题,运用层簇式网络结构,通过身份加密方式,进行节点合法性认证,完成基站与簇头,簇头与节点之间的密钥,保证无线传感器网络安全通信。通过安全性分析和效能分析,该密钥管理方案较好的满足无线传感器网络的安全需求,降低通信开销,有效地解决密钥管理的问题。%Key management is one of the key security technology in wireless sensor networks .The key management of wireless sensor network because the arrangement widely ,calculation ,storage capacity is limited ,which makes the design fa‐cing a lot of challenges .Based on the analysis of the security requirements of wireless sensor networks ,aiming at the key management problem in wireless sensor networks ,application layer cluster network structure ,the identity based encryption method ,node legitimacy authentication ,the paper complete key management of the base station and cluster head and between the cluster head and the node key ,to ensure the safety of communication in wireless sensor network .Through the analysis of security and performance ,the key management scheme satisfies the security requirements of wireless sensor network ,reduce the communication cost ,solve the effective key management problems .

  1. 基于中国剩余定理的传感器网络密钥管理协议%A Novel Key Management Scheme Based on the Chinese Remainder Theorem for Wireless Sensor Networks

    Institute of Scientific and Technical Information of China (English)

    陈琳

    2014-01-01

    无线传感器网络的安全性是目前研究的热点。传统基于临时初始密钥和基于密钥池预分配的方案难以在网络连通性和节点存储计算消耗之间有效平衡,网络生命期内使用固定不变的初始密钥/密钥池难以抵抗节点捕获攻击。本文基于中国剩余定理提出了传感器网络密钥管理协议,每个节点携带较少的密钥素材,能够实现网络最大连通,并具有较少的存储空间和计算与通信能耗;基于时间概念分多个阶段部署传感器节点时,发布的密钥素材在不同的节点部署阶段相应变化,使得网络具有自愈合功能,从而具有较强的抗节点捕获攻击。%Research of security problem in wireless sensor networks( WSNs) is a challenging hotspot over the last ten years. Traditional schemes those based on temporary initial key and key pre-distribution using key pools are difficult to be tradeoff between the network connectivity and node storage space,and the same initial key or the key pool in these approaches is also vulnerable to against node capture attacks,this leaves key management as a fundamental research topic in the field of WSNs security. In this paper,a novel time-based key management scheme for WSNs using the Chinese Remainder Theorem is proposed, in our strategy each sensor node with fewer key material is deployed over different time stage,and the important parameter in key materials change correspondingly over time. We introduce the process of pair-wise key create, node addition and revocation, and show that the proposed key management solution can achieve maximum network connectivity with less energy consumption about communication and calculation,and also make the network has self-healing function and strong resistance to node capture attack.

  2. Quantum Authentication Based on the Lengthened String Scheme

    Institute of Scientific and Technical Information of China (English)

    GUO Fen-zhuo; WEN Qiao-yan; ZHU Fu-chen

    2004-01-01

    Assuming there is a shared string between the users, we present a novel scheme, the lengthened string scheme (LSS), where the shared string is lengthened firstly by a specially designed algorithm, then some special treatments are applied on the lengthened one before it is used to authenticate. Based on the lengthened string scheme (LSS) we propose a quantum authentication protocol using entanglements. And the robustness of our protocol is discussed. In fact all the quantum key distribution protocols can do identification simultaneously based on the LSS.

  3. A SECURE PROXY SIGNATURE SCHEME BASED ON ELLIPTIC CURVE CRYPTOSYSTEM

    Institute of Scientific and Technical Information of China (English)

    Hu Bin; Jin Chenhui

    2006-01-01

    Proxy signature is a special digital signature which enables a proxy signer to sign messages on behalf of the original signer. This paper proposes a strongly secure proxy signature scheme and a secure multi-proxy signature scheme based on elliptic curve cryptosystem. Contrast with universal proxy signature schemes, they are secure against key substitute attack even if there is not a certificate authority in the system,and also secure against the original signer's forgery attack. Furthermore, based on the elliptic curve crypto system, they are more efficient and have smaller key size than other system. They can be used in electronics transaction and mobile agent environment.

  4. Cocoa farmers'perception of Community Based Nursery Scheme: A ...

    African Journals Online (AJOL)

    Cocoa farmers'perception of Community Based Nursery Scheme: A case study ... Sustainable Tree Crop Programme (STCP)| -Nigeria established Community ... for self improvement of participating farmers (8.3%) and group efforts/ formation ...

  5. A threshold key escrow scheme based on public key cryptosystem

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In key escrow field it is important to solve the problem thatuser's secret key completely depends on the trusted escrow agency. In 1995, some methods of solving the problem were presented. But these methods are no better than that of directly using threshold cryptography. In this paper, we present a common pattern of threshold key escrow scheme based on public key cryptosystem, and a detailed design based on the improved RSA algorithm is given. The above problem is solved by this scheme.

  6. An expert system based intelligent control scheme for space bioreactors

    Science.gov (United States)

    San, Ka-Yiu

    1988-01-01

    An expert system based intelligent control scheme is being developed for the effective control and full automation of bioreactor systems in space. The scheme developed will have the capability to capture information from various resources including heuristic information from process researchers and operators. The knowledge base of the expert system should contain enough expertise to perform on-line system identification and thus be able to adapt the controllers accordingly with minimal human supervision.

  7. DISTRIBUTED CERTIFICATE AUTHORITY IN CLUSTER-BASED MANET USING MULTI SECRET SHARING SCHEME

    Directory of Open Access Journals (Sweden)

    Mohammed Azza

    2015-11-01

    Full Text Available Providing secure communications in mobile ad hoc networks (MANET is an important and difficult problem, due to a lack of a key management infrastructure. The authentication is an important security service in (MANETs. To provide a node authentication service we use a fully distributed certificate authorities (FDCA based on the threshold cryptography. In this paper we propose an efficient and verifiable multi secret sharing scheme in cluster-based MANET with a low computation system. Our scheme is based on the overdetermined linear system equation in Galois fields GF(2r. We have analyzed our scheme based on security and performance criteria, and compared with existing approaches. The efficiency of our proposed schemes was verified and evaluated by simulation. Simulation results show that this approach is scalable.

  8. A Secure Code-Based Authentication Scheme for RFID Systems

    Directory of Open Access Journals (Sweden)

    Noureddine Chikouche

    2015-08-01

    Full Text Available Two essential problems are still posed in terms of Radio Frequency Identification (RFID systems, including: security and limitation of resources. Recently, Li et al.'s proposed a mutual authentication scheme for RFID systems in 2014, it is based on Quasi Cyclic-Moderate Density Parity Check (QC-MDPC McEliece cryptosystem. This cryptosystem is designed to reducing the key sizes. In this paper, we found that this scheme does not provide untraceability and forward secrecy properties. Furthermore, we propose an improved version of this scheme to eliminate existing vulnerabilities of studied scheme. It is based on the QC-MDPC McEliece cryptosystem with padding the plaintext by a random bit-string. Our work also includes a security comparison between our improved scheme and different code-based RFID authentication schemes. We prove secrecy and mutual authentication properties by AVISPA (Automated Validation of Internet Security Protocols and Applications tools. Concerning the performance, our scheme is suitable for low-cost tags with resource limitation.

  9. Anomaly Detection for Internet of Vehicles: A Trust Management Scheme with Affinity Propagation

    Directory of Open Access Journals (Sweden)

    Shu Yang

    2016-01-01

    Full Text Available Anomaly detection is critical for intelligent vehicle (IV collaboration. Forming clusters/platoons, IVs can work together to accomplish complex jobs that they are unable to perform individually. To improve security and efficiency of Internet of Vehicles, IVs’ anomaly detection has been extensively studied and a number of trust-based approaches have been proposed. However, most of these proposals either pay little attention to leader-based detection algorithm or ignore the utility of networked Roadside-Units (RSUs. In this paper, we introduce a trust-based anomaly detection scheme for IVs, where some malicious or incapable vehicles are existing on roads. The proposed scheme works by allowing IVs to detect abnormal vehicles, communicate with each other, and finally converge to some trustworthy cluster heads (CHs. Periodically, the CHs take responsibility for intracluster trust management. Moreover, the scheme is enhanced with a distributed supervising mechanism and a central reputation arbitrator to assure robustness and fairness in detecting process. The simulation results show that our scheme can achieve a low detection failure rate below 1%, demonstrating its ability to detect and filter the abnormal vehicles.

  10. A New ID-Based Proxy Blind Signature Scheme

    Institute of Scientific and Technical Information of China (English)

    LANG Wei-min; YANG Zong-kai; CHENG Wen-qing; TAN Yun-meng

    2005-01-01

    An identity-based proxy blind signature scheme from bilinear pairings is introduced, which combines the advantages of proxy signature and blind signature. Furthermore, our scheme can prevent the original signer from generating the proxy blind signature, thus the profits of the proxy signer are guaranteed. We introduce bilinear pairings to minimize computational overhead and to improve the related performance of our scheme. In addition, the proxy blind signature presented is non-repudiable and it fulfills perfectly the security requirements of a proxy blind signature.

  11. Regulation control and energy management scheme for wireless power transfer

    Energy Technology Data Exchange (ETDEWEB)

    Miller, John M.

    2015-12-29

    Power transfer rate at a charging facility can be maximized by employing a feedback scheme. The state of charge (SOC) and temperature of the regenerative energy storage system (RESS) pack of a vehicle is monitored to determine the load due to the RESS pack. An optimal frequency that cancels the imaginary component of the input impedance for the output signal from a grid converter is calculated from the load of the RESS pack, and a frequency offset f* is made to the nominal frequency f.sub.0 of the grid converter output based on the resonance frequency of a magnetically coupled circuit. The optimal frequency can maximize the efficiency of the power transfer. Further, an optimal grid converter duty ratio d* can be derived from the charge rate of the RESS pack. The grid converter duty ratio d* regulates wireless power transfer (WPT) power level.

  12. Assessing Risk Management Capability of Public Sector Organizations Related to PPP Scheme Development for Water Supply in Indonesia

    Directory of Open Access Journals (Sweden)

    Pangeran M.H.

    2012-01-01

    Full Text Available The success of Public Private Partnership (PPP for water supply investment is inseparable from the capability of risk management of the parties within the project. This study investigates the risk management capability of Indonesian local public sector organizations that are potentially involved in PPP schemes for water supply. A risk management maturity model based assessment tool probing the culture, process, experience, application and partnership aspects is used in the survey. The model describes risk management capability in four levels (ad-hoc, initial, competent, excellent. The survey shows that their risk management capability is still in-average at the initial stage (level 2, meaning that the adopted risk management postures are mostly supported only by unstructured, ad-hoc and non-formal processes. The result of this study can help decision makers in choosing appropriate risk management methods and tools to be used by the local public authorities for managing risks in PPP schemes.

  13. An Identity-Based Scheme of Fair Exchange of Digital Signatures

    Institute of Scientific and Technical Information of China (English)

    YU Yong; YANG Bo; YANG Guoqing

    2006-01-01

    Fair exchange of digital signatures is an important tool for signing digital contracts, e-payment and other electronic commerce actions. An ID-based scheme of fair exchange of digital signature is proposed in this paper. The protocol relies on a trusted third party, but is "optimistic", in that the third party is only needed in cases where one player attempts to cheat or simply crashes. The proposed scheme has properties of short signature, low computation and verification cost. It can realize exchange of digital signatures fairly and efficiently. A key feature of our scheme is that it is identity-based, which needs no certificates and has a simple key management. To our best knowledge, this is the first identity-based scheme of fair exchange of digital signatures.

  14. Generic-Model-Based Description Scheme for MPEG-7

    Institute of Scientific and Technical Information of China (English)

    Deng Juan; Tan Hut; Chen Xin-meng

    2004-01-01

    We propose a new description scheme for MPEG7-: Generic-model-based Description Scheme to describe contents of audio, video, text and other sorts of multimedia.It uses a generic model as the description frame, which provides a simple but useful object-based structure. The main components of the description scheme are generic model, objects and object fcatures. The proposed description scheme is illustrated and exemplified by Extensible Markup Language.It aims at clarity and flexibility to support MPEG-7 applications such as query and edit. We demonstrate its feasibility and efficiency by presenting applications: Digital Broadcasting and Edit System (DEBS) and Non-linear Edit System (NLES) that already used the generic structure or will greatly benefit from it.

  15. A Directly Public Verifiable Signcryption Scheme based on Elliptic Curves

    CERN Document Server

    Toorani, Mohsen; 10.1109/ISCC.2009.5202242

    2010-01-01

    A directly public verifiable signcryption scheme is introduced in this paper that provides the security attributes of message confidentiality, authentication, integrity, non-repudiation, unforgeability, and forward secrecy of message confidentiality. It provides the attribute of direct public verifiability so anyone can verify the signcryption without any need for any secret information from the corresponding participants. The proposed scheme is based on elliptic curve cryptography and is so suitable for environments with resource constraints.

  16. Markov chaotic sequences for correlation based watermarking schemes

    Energy Technology Data Exchange (ETDEWEB)

    Tefas, A.; Nikolaidis, A.; Nikolaidis, N.; Solachidis, V.; Tsekeridou, S.; Pitas, I. E-mail: pitas@zeus.csd.auth.gr

    2003-07-01

    In this paper, statistical analysis of watermarking schemes based on correlation detection is presented. Statistical properties of watermark sequences generated by piecewise-linear Markov maps are exploited, resulting in superior watermark detection reliability. Correlation/spectral properties of such sequences are easily controllable, a fact that affects the watermarking system performance. A family of chaotic maps, namely the skew tent map family, is proposed for use in watermarking schemes.

  17. An Efficient Attack on a Code-Based Signature Scheme

    OpenAIRE

    Phesso, Aurélie; Tillich, Jean-Pierre

    2016-01-01

    International audience; Baldi et al. have introduced in [BBC + 13] a very novel code based signature scheme. However we will prove here that some of the bits of the signatures are correlated in this scheme and this allows an attack that recovers enough of the underlying secret structure to forge new signatures. This cryptanalysis was performed on the parameters which were devised for 80 bits of security and broke them with 100, 000 signatures originating from the same secret key.

  18. Modeling Prioritized Hard Handoff Management Scheme for Wireless Mobile Networks

    Directory of Open Access Journals (Sweden)

    BISWAJIT BHOWMIK

    2012-08-01

    Full Text Available The channel associated with the current connection serviced by a base station is changed while a call is in progress. Usually, continuous service is achieved by supporting handoff from one cell to another. It is often initiated either by crossing a cell boundary or by deterioration in quality of the signal in the current channel. The existing call is then changed to a new base station. For the traffics which are non stationary at and are away from the servicing base station, the chances of a call to be handed off are increasing. In this paper we propose a scheme MH_2S to modeling and implementing a traffic model with handoff behavior for wireless mobile networks . The simulation model MH_2S with priority is developed to investigate the performance behavior of hard handoff strategy. Novelty of the proposed model MH_2S results that it can improve call blocking rate of handoff calls. In addition to this, measurement of blocking probabilities for both originating calls and handoff calls is another impressive achievement of the model.

  19. Communication scheme based on evolutionary spatial 2×2 games

    Science.gov (United States)

    Ziaukas, Pranas; Ragulskis, Tautvydas; Ragulskis, Minvydas

    2014-06-01

    A visual communication scheme based on evolutionary spatial 2×2 games is proposed in this paper. Self-organizing patterns induced by complex interactions between competing individuals are exploited for hiding and transmitting secret visual information. Properties of the proposed communication scheme are discussed in details. It is shown that the hiding capacity of the system (the minimum size of the detectable primitives and the minimum distance between two primitives) is sufficient for the effective transmission of digital dichotomous images. Also, it is demonstrated that the proposed communication scheme is resilient to time backwards, plain image attacks and is highly sensitive to perturbations of private and public keys. Several computational experiments are used to demonstrate the effectiveness of the proposed communication scheme.

  20. Satisfaction with the level and type of resource use of a health insurance scheme in Nigeria: health management organizations' perspectives.

    Science.gov (United States)

    Mohammed, Shafiu; Souares, Aurelia; Lorenzo Bermejo, Justo; Babale, Sufiyan Muawiyyah; Sauerborn, Rainer; Dong, Hengjin

    2014-01-01

    Some developing countries have incorporated managed care elements into their national health insurance schemes. In practice, hybrid health management organizations (Hmos) are insurers who, bearing some resemblance to managed care in the USA, are vertically integrated in the scheme's revenue collection and pool and purchase healthcare services within a competitive framework. To date, few studies have focused on these organizations and their level of satisfaction with the scheme's optimal-resource-use (ORU) implementation. In Nigeria, the study site, Hmos were categorized on the basis of their satisfaction with ORU activities. One hundred forty-seven Hmo staff were randomly interviewed. The types of ORU domain categories were provider payment mechanism, administrative efficiency, benefit package inclusions and active monitoring mechanism. Bivariate analysis was used to determine differences among the Hmos' satisfaction with the various ORU domains. The Hmos' satisfaction with the health insurance scheme's ORU activities was 59.2% generally, and the associated factors were identified. According to the Hmos' perspectives related to the type of ORU, the fee-for-service payment method and regular inspection performed weakly. Hmos' limited satisfaction with the scheme's ORU raises concerns regarding ineffectiveness that may hinder implementation. To offset high risks in the scheme, it appears necessary for the regulatory agency to adapt and reform strategies of provider payment and active monitoring mechanisms according to stakeholder needs. Our findings further reveal that having Hmos evaluate ORU is useful for providing evidence-based information for policy making and regulatory utilization related to implementation of the health insurance scheme.

  1. A scalable admission control scheme based on time label

    Institute of Scientific and Technical Information of China (English)

    杨松岸; 杨华; 杨宇航

    2004-01-01

    Resource reservation protocols allow communicating hosts to reserve resources such as bandwidth to offer guaranteed service. However,current resource reservation architectures do not scale well for a large number of flows. In this paper,we present a simple reservation protocol and a scalable admission control algorithm,which can provide QoS guarantees to individual flows without per-flow management in the network core. By mapping each flow to a definite time,this scheme addresses the problems that limit the effectiveness of current endpoint admission control schemes. The overall admission control process is described. Analysis is used to explain the reasonability of our scheme and simulation validates its performance.

  2. Goose management schemes to resolve conflicts with agriculture: Theory, practice and effects.

    Science.gov (United States)

    Eythórsson, Einar; Tombre, Ingunn M; Madsen, Jesper

    2017-03-01

    In 2012, the four countries hosting the Svalbard population of pink-footed goose Anser brachyrhynchus along its flyway launched an International Species Management Plan for the population. One of the aims was to reduce conflicts between geese and agriculture to an acceptable level. Since 2006, Norway has offered subsidies to farmers that provide refuge areas for geese on their land. We evaluate the mid-Norwegian goose management subsidy scheme, with a view to its adjustment to prevailing ecological and socio-economic parameters. The analysis indicates that the legitimacy of the scheme is highly dependent on transparency of knowledge management and accountability of management scheme to the farming community. Among farmers, as well as front-line officials, outcomes of prioritisation processes within the scheme are judged unfair when there is an evident mismatch between payments and genuine damage. We suggest how the scheme can be made more fair and responsive to ecological changes, within a framework of adaptive management.

  3. A Study on Making greens in the Waterside and Management Scheme for Water-Purity Improvement

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Ji Yong; Jeong Yoo Jin [Korea Environment Institute, Seoul (Korea)

    2000-12-01

    The vegetation area has several kinds of functions to reserve water, remove the toxicity in the water, and provide the habitats for land/water plants and animals. Until now, however, the waterside has been injudiciously developed because it has not been recognized that the waterside is important for the water-purity improvement and water-quantity security. Fortunately, the Government introduced the waterside-zone system to conserve and improve the water-purity of the water-service source in 'the Special All-Out Policy on Water-Purity Control in Han-Riverside Water Source such as Paldang-lake', as a pre cautious measure in November 1998. The making greens in the waterside-zone is a scheme to perform several functions, such as the enhancement of people's psychological safety on water-purity, the offer of water-friendly environment, and the protection of ecosystem as well as the improvement of water-purity. However, the realistic difficulties in making greens in the waterside are expected due to the insufficient pre-research on the management scheme for greens in the waterside. This study is the timely and necessary, which suggests the theoretical system on the greens in the waterside and the making greens in the waterside and the management scheme based on the water-purity improvement. In making greens in the waterside-zone of expanding application to big-4 rivers, the basic scheme of this study is faithfully performed so the goal of indicating the waterside-zone for water pollution preparation must be achieved. The continuous research on the greens in the waterside must be also promoted, such as the detailed scheme on the making greens in the waterside by regional feature, the inspection on the water-purity improvement effect by making greens, and the examination of the pollution purification function by making greens. 32 refs., 6 figs., 27 tabs.

  4. An Efficient Content Based Image Retrieval Scheme

    Directory of Open Access Journals (Sweden)

    Zukuan WEI

    2013-11-01

    Full Text Available Due to the recent improvements in digital photography and storage capacity, storing large amounts of images has been made possible. Consequently efficient means to retrieve images matching a user’s query are needed. In this paper, we propose a framework based on a bipartite graph model (BGM for semantic image retrieval. BGM is a scalable data structure that aids semantic indexing in an efficient manner, and it can also be incrementally updated. Firstly, all the images are segmented into several regions with image segmentation algorithm, pre-trained SVMs are used to annotate each region, and final label is obtained by merging all the region labels. Then we use the set of images and the set of region labels to build a bipartite graph. When a query is given, a query node, initially containing a fixed number of labels, is created to attach to the bipartite graph. The node then distributes the labels based on the edge weight between the node and its neighbors. Image nodes receiving the most labels represent the most relevant images. Experimental results demonstrate that our proposed technique is promising.

  5. A new improved ID-based proxy ring signature scheme from bilinear pairings

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Ring signature and proxy signature are of vital importance to secure electronic commerce. Recently,the bilinear pairing such as Weil pairing or Tate pairing on elliptic curves and hyperelliptic curves is playing an important role in security solutions. Several ID-based signature schemes have been put forward, many of which are based on bilinear pairings. In key management and moderate security demand scenarios, ID-based public key cryptosystem is more preferable than other public key infrastructure based systems. In this paper, an improved ID-based proxy ring signature scheme from bilinear pairings is proposed which combines the advantages of proxy signature and of ring signatures. Our scheme can guarantee the profits of the proxy signer via preventing the original signer form generating the proxy ring signature. Furthermore, bilinear pairings are introduced to minimize the computation overhead and to improve the related performance of our scheme. In contrast with Zhang's scheme, our scheme is a computational efficiency improvement for signature verification because the computational cost of bilinear pairings required is reduced from O(n) to O( 1 ). In addition, the proxy ring signature presented in this paper can perfectly satisfy all the security requirements of proxy ring signature, i.e.signer-ambiguity, non-forgeability, verification, non-deniability and distinguishability.

  6. Complex scheme of company image management on the stages of its life cycle

    Directory of Open Access Journals (Sweden)

    A.V. Kolodka

    2014-03-01

    Full Text Available The aim of the article. The aim of the article is to create a common integrated circuit image management during a life-cycle of enterprise based on internal and external economic conditions. The results of the analysis. In the article the general scheme of image management during a life-cycle of enterprise based on internal and external economic conditions is formed. There is no single view on the question of forming general concepts and approaches to image building. That threatens making the correct management actions in developing and strengthening the image by top professionals. In the article several tasks were accomplished for achieving the main goal. The basic concepts of formation and management of the company image are analyzed. According to this the main tasks of image policy on company life-cycle, the activities on the formation of internal and external image were defined. The approaches of the formation and company image management are analyzed. The features and the necessity of using different approaches to image management at each stage of the company life cycle are highlighted. Research results of modern approaches to the company image formation serve the goals of reconstruction a coherent picture of this management problem were developed. The author proved that measures for formation and management of company image should be based on the analysis of existing conditions of its image and stages of its life cycle, which will increase the efficiency of management. Conclusions and directions of further researches. Completed the system analysis of the concepts and approaches to the formation and the company image management, revealed their strengths and weaknesses. The conceptual scheme of the purposeful control of company image on the stages of its life cycle was developed. Recommendations how to use the approaches to manage company image on its life-cycle were proposed.The results obtained allow forming the image policy, which is

  7. A Novel Broadcast Scheme DSR-based Mobile Adhoc Networks

    Directory of Open Access Journals (Sweden)

    Muneer Bani Yassein

    2016-04-01

    Full Text Available Traffic classification seeks to assign packet flows to an appropriate quality of service (QoS. Despite many studies that have placed a lot of emphasis on broadcast communication, broadcasting in MANETs is still a problematic issue. Due to the absence of the fixed infrastructure in MANETs, broadcast is an essential operation for all network nodes. Although the blind flooding is the simplest broadcasting technique, it is inefficient and lacks resource utilization efficiency. One of the proposed schemes to mitigate the blind flooding deficiency is the counter based broadcast scheme that depends on the number of received duplicate packets between the node and its neighbors, where the node compares the duplicate packet itself and each neighbor node that previously re-broadcasted a packet. Due to the fact that existing counter-based schemes are mainly based on the fixed counter based approach, these schemes are not efficient in different operating conditions. Thus, unlike existing studies, this paper proposes a dynamic counter based threshold value and examines its effectiveness under the Dynamic Source Routing Protocol (DSR which is one of the well-known on-demand routing protocols. Specifically, we develop in this paper a new counter based broadcast algorithm under the umbrella of the DSR, namely, Inspired Counter Based Broadcasting (DSR-ICB. Using various simulation experiments, DSR-ICB has shown good performance especially in terms of delay and the number of redundant packets.

  8. Soil quality under two different management schemes in coffee plantations of southern Colombia.

    Directory of Open Access Journals (Sweden)

    Oscar Eduardo Valbuena-Calderón

    2016-12-01

    Full Text Available The aim of this work was to develop an additive soil quality index (ASQI in agrofostery managements of coffee (Coffea arabica L.. The study took place under two intense and traditional management schemes, in nine farms (32 lots in the south of Colombia, during 2013. A separation of means analysis was held through the LSD Fisher test (P<0,05 to each of the physical and chemical variables of the soil. The variables that showed differences between the schemes were submitted to a main components analysis to select the minimum data set (MDS of the components that explained the most variability and the redundancy was veri ed within the indicators, based on the correlation. The ASQI was obtained from the total sum of soil quality index (SQI of all the indicators, taking into account that the higher the score of the ASQI, the higher the quality of the soil within the study system. The selected physical variables were the content of sand and clay; while the chemical variables were: organic carbon (OC, P, CA, Mg, total bases (TB and Ca/Mg. The best ASQI was obtained from traditional management, because the value of the selected variables matched in a bigger proportion with the quality objective identi ed for the ASQI quanti cation; in this case the crop yield, based on limit values for coffee plantations.

  9. An Elliptic Curve-based Signcryption Scheme with Forward Secrecy

    CERN Document Server

    Toorani, Mohsen; 10.3923/jas.2009.1025.1035

    2010-01-01

    An elliptic curve-based signcryption scheme is introduced in this paper that effectively combines the functionalities of digital signature and encryption, and decreases the computational costs and communication overheads in comparison with the traditional signature-then-encryption schemes. It simultaneously provides the attributes of message confidentiality, authentication, integrity, unforgeability, non-repudiation, public verifiability, and forward secrecy of message confidentiality. Since it is based on elliptic curves and can use any fast and secure symmetric algorithm for encrypting messages, it has great advantages to be used for security establishments in store-and-forward applications and when dealing with resource-constrained devices.

  10. Judgement of Design Scheme Based on Flexible Constraint in ICAD

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The conception of flexible constraint is proposed in the paper. The solution of flexible constraint is in special range, and maybe different in different instances of same design scheme. The paper emphasis on how to evaluate and optimize a design scheme with flexible constraints based on the satisfaction degree function defined on flexible constraints. The conception of flexible constraint is used to solve constraint conflict and design optimization in complicated constraint-based assembly design by the PFM parametrization assembly design system. An instance of gear-box design is used for verifying optimization method.

  11. A Zone-Based Self-Organized Handover Scheme for Heterogeneous Mobile and Ad Hoc Networks

    OpenAIRE

    Murad Khan; Kijun Han

    2014-01-01

    Uninterrupted internet services are need of the day and their demand will increase in future by manifold. However, providing uninterrupted services under heterogeneous networks environment is a challenging task. One of the major challenges in this regard is the management of handover system between various networks. This paper proposes a handover management scheme by dividing the total coverage area of the base station (BS) or access point (AP) into three different zones (strong, average, and...

  12. A Detection Scheme for Cavity-based Dark Matter Searches

    CERN Document Server

    Bukhari, M H S

    2016-01-01

    We present here proposal of a scheme and some useful ideas for resonant cavity-based detection of cold dark matter axions with hope to improve the existing endeavors. The scheme is based upon our idea of a detector, which incorporates an integrated tunnel diode and a GaAs HEMT or HFET, High Electron Mobility Transistor or Heterogenous FET, for resonance detection and amplification from a resonant cavity (in a strong transverse magnetic field from a cylindrical array of halbach magnets). The idea of a TD-oscillator-amplifier combination could possibly serve as a more sensitive and viable resonance detection regime while maintaining an excellent performance with low noise temperature, whereas the halbach magnets array may offer a compact and permanent solution replacing the conventional electromagnets scheme. We believe that all these factors could possibly increase the sensitivity and accuracy of axion detection searches and reduce complications (and associated costs) in the experiments, in addition to help re...

  13. Cascaded Fresnel holographic image encryption scheme based on a constrained optimization algorithm and Henon map

    Science.gov (United States)

    Su, Yonggang; Tang, Chen; Chen, Xia; Li, Biyuan; Xu, Wenjun; Lei, Zhenkun

    2017-01-01

    We propose an image encryption scheme using chaotic phase masks and cascaded Fresnel transform holography based on a constrained optimization algorithm. In the proposed encryption scheme, the chaotic phase masks are generated by Henon map, and the initial conditions and parameters of Henon map serve as the main secret keys during the encryption and decryption process. With the help of multiple chaotic phase masks, the original image can be encrypted into the form of a hologram. The constrained optimization algorithm makes it possible to retrieve the original image from only single frame hologram. The use of chaotic phase masks makes the key management and transmission become very convenient. In addition, the geometric parameters of optical system serve as the additional keys, which can improve the security level of the proposed scheme. Comprehensive security analysis performed on the proposed encryption scheme demonstrates that the scheme has high resistance against various potential attacks. Moreover, the proposed encryption scheme can be used to encrypt video information. And simulations performed on a video in AVI format have also verified the feasibility of the scheme for video encryption.

  14. Current practice with regard to short-term incentive schemes for middle managers

    Directory of Open Access Journals (Sweden)

    Chrisilla Grigoiadis

    2007-01-01

    Full Text Available This study aimed to determine what the current practice is with regard to short-term incentive schemes for middle managers. This was done by means of a quantitative study through a structured research survey completed by a sample of forty-eight organisations. The design elements, performance measures and payout practices of the various schemes in use were surveyed, as well as the participants’ view on the perceived effectiveness of their short-term incentive schemes. Evidence shows that the majority of organisations have a short-term incentive scheme in place for middle managers, and that the type of scheme used in most of the organisations is a performance-related bonus scheme, introduced mainly to drive business performance and reward superior performance.

  15. Deflection routing scheme for GMPLS-based OBS networks

    DEFF Research Database (Denmark)

    Eid, Arafat; Mahmood, Waqar; Alomar, Anwar

    2010-01-01

    is not applicable in such an integrated solution. This is due to the existence of already established Label Switched Paths (LSPs) between edge nodes in a GMPLS-based OBS network which guide the Data Burst Headers (DBHs) through the network. In this paper we propose a novel deflection routing scheme which can...

  16. DWT-Based Watermarking Scheme for Digital Images

    Institute of Scientific and Technical Information of China (English)

    何泉; 苏广川

    2003-01-01

    A watermarking scheme for digital images is introduced. This method is based on discrete wavelet transform and spread spectrum technique. A discrete wavelet transformed binary signature image is expanded by an m-sequence and added to the large wavelet coefficients of a host image with a scale factor. Good balance between transparency and robustness is achieved by the selection of the scale factor. In addition, the spread spectrum technique is adopted to increase the robustness of this watermarking scheme. The experimental results show that the proposed method is of good performance and robustness for common image operations such as JPEG lossy compression, etc.

  17. A Fair E-Cash Payment Scheme Based on Credit

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A new fair e-cash payment scheme based on credit is present in this paper. In the scheme, an overdraft credit certificate is issued to user by bank. Using the overdraft credit certificate, user can produce e-cash himself to pay in exchanges. Merchant can verify the e-cash received from user. Bank can make a fair dispute resolution when there is a dissension between user and merchant. It can avoid the problem of partition e-cash for changes, prevent from reusing e-cash and faking e-cash. It fits justice, anonymity, non-deny and impartiality.

  18. A Novel Block-Based Scheme for Arithmetic Coding

    Directory of Open Access Journals (Sweden)

    Qi-Bin Hou

    2014-06-01

    Full Text Available It is well-known that for a given sequence, its optimal codeword length is fixed. Many coding schemes have been proposed to make the codeword length as close to the optimal value as possible. In this paper, a new block-based coding scheme operating on the subsequences of a source sequence is proposed. It is proved that the optimal codeword lengths of the subsequences are not larger than that of the given sequence. Experimental results using arithmetic coding will be presented.

  19. Block-based adaptive lifting schemes for multiband image compression

    Science.gov (United States)

    Masmoudi, Hela; Benazza-Benyahia, Amel; Pesquet, Jean-Christophe

    2004-02-01

    In this paper, we are interested in designing lifting schemes adapted to the statistics of the wavelet coefficients of multiband images for compression applications. More precisely, nonseparable vector lifting schemes are used in order to capture simultaneously the spatial and the spectral redundancies. The underlying operators are then computed in order to minimize the entropy of the resulting multiresolution representation. To this respect, we have developed a new iterative block-based classification algorithm. Simulation tests carried out on remotely sensed multispectral images indicate that a substantial gain in terms of bit-rate is achieved by the proposed adaptive coding method w.r.t the non-adaptive one.

  20. Wavelet based hierarchical coding scheme for radar image compression

    Science.gov (United States)

    Sheng, Wen; Jiao, Xiaoli; He, Jifeng

    2007-12-01

    This paper presents a wavelet based hierarchical coding scheme for radar image compression. Radar signal is firstly quantized to digital signal, and reorganized as raster-scanned image according to radar's repeated period frequency. After reorganization, the reformed image is decomposed to image blocks with different frequency band by 2-D wavelet transformation, each block is quantized and coded by the Huffman coding scheme. A demonstrating system is developed, showing that under the requirement of real time processing, the compression ratio can be very high, while with no significant loss of target signal in restored radar image.

  1. A novel current-sharing scheme based on magamp

    Institute of Scientific and Technical Information of China (English)

    Wen-xi YAO; Xiao-yuan HONG; Zheng-yu LU

    2008-01-01

    The magamp (magnetic amplifier) is widely used in power supplies due to its low cost,simplicity and other advantages.This paper discusses a novel application of the magamp in switching power supplies,where the magamp is used to regulate pulse width modulation (PWM) instead of power signal in the main circuit.This method extends the application of the magamp in power supplies,and makes it possible to further regulate control signal when PWMs have been generated.Based on this application,a new current-sharing (CS) scheme using the magamp is proposed,which uses a modified inner loop CS structure.In this scheme PWMs are generated by one main controller,and CS is achieved by regulating PWMs using a magamp in each module.Compared with traditional application of the magamp,the new CS scheme can be used in most topologies and only requires magamps of low power capacity.Then a test circuit of parallel power supply is developed,in which CS is achieved by a PWM regulator with the magamp.The proposed scheme is also used to upgrade an electroplate power to make it capable of paralleling supplies.Experimental results show that the proposed scheme has good CS performance.

  2. A Sweep Coverage Scheme Based on Vehicle Routing Problem

    Directory of Open Access Journals (Sweden)

    Li Shu

    2013-04-01

    Full Text Available As an emerging coverage problem in wireless sensor networks, sweep coverage which introducing mobile sensors to cover points of interest within certain time interval can satisfy monitoring request in some particular application scenarios with less number of nodes than the conventional static coverage approach. In this work, aiming to support dynamical POI coverage and data delivery simultaneously, a novel sweep coverage scheme, named VRPSC(Vehicle Routing Problem based Sweep Coverage, is proposed by modeling the minimum number of required sensors problem in sweep coverage as a Vehicle Routing Problem (VRP. In VRPSC, an insertion algorithm is first introduced to create the initial scanning routes for POIs, and then the Simulated Annealing is employed to optimize these routes. The simulation results show that the VRPSC scheme achieves better performance than existing schemes

  3. A privacy authentication scheme based on cloud for medical environment.

    Science.gov (United States)

    Chen, Chin-Ling; Yang, Tsai-Tung; Chiang, Mao-Lun; Shih, Tzay-Farn

    2014-11-01

    With the rapid development of the information technology, the health care technologies already became matured. Such as electronic medical records that can be easily stored. However, how to get medical resources more convenient is currently concerning issue. In spite of many literatures discussed about medical systems, these literatures should face many security challenges. The most important issue is patients' privacy. Therefore, we propose a privacy authentication scheme based on cloud environment. In our scheme, we use mobile device's characteristics, allowing peoples to use medical resources on the cloud environment to find medical advice conveniently. The digital signature is used to ensure the security of the medical information that is certified by the medical department in our proposed scheme.

  4. An Efficient Provable Secure ID-Based Proxy Signature Scheme Based on CDH Assumption

    Institute of Scientific and Technical Information of China (English)

    CHAI Zhen-chuan; CAO Zhen-fu; LU Rong-xing

    2006-01-01

    Identity-based proxy signature enables an entity to delegate its signing rights to another entity in identity-based cryptosystem settings. However, few existing scheme has been proved secure in a formalized model, or acquired optimized performance. To achieve the goals of both proven security and high efficiency, this paper proposed an efficient identity-based proxy signature scheme. The scheme is constructed from bilinear pairing and proved secure in the random oracle model, using the oracle replay attack technique introduced by Pointchval and Stern. The analysis shows that the scheme needs less computation costs and has a shorter signature than the other schemes.

  5. A comparison of temperature and precipitation responses to different Earth radiation management geoengineering schemes

    Science.gov (United States)

    Crook, J. A.; Jackson, L. S.; Osprey, S. M.; Forster, P. M.

    2015-09-01

    Earth radiation management has been suggested as a way to rapidly counteract global warming in the face of a lack of mitigation efforts, buying time and avoiding potentially catastrophic warming. We compare six different radiation management schemes that use surface, troposphere, and stratosphere interventions in a single climate model in which we projected future climate from 2020 to 2099 based on RCP4.5. We analyze the surface air temperature responses to determine how effective the schemes are at returning temperature to its 1986-2005 climatology and analyze precipitation responses to compare side effects. We find crop albedo enhancement is largely ineffective at returning temperature to its 1986-2005 climatology. Desert albedo enhancement causes excessive cooling in the deserts and severe shifts in tropical precipitation. Ocean albedo enhancement, sea-spray geoengineering, cirrus cloud thinning, and stratospheric SO2 injection have the potential to cool more uniformly, but cirrus cloud thinning may not be able to cool by much more than 1 K globally. We find that of the schemes potentially able to return surface air temperature to 1986-2005 climatology under future greenhouse gas warming, none has significantly less severe precipitation side effects than other schemes. Despite different forcing patterns, ocean albedo enhancement, sea-spray geoengineering, cirrus cloud thinning, and stratospheric SO2 injection all result in large scale tropical precipitation responses caused by Hadley cell changes and land precipitation changes largely driven by thermodynamic changes. Widespread regional scale changes in precipitation over land are significantly different from the 1986-2005 climatology and would likely necessitate significant adaptation despite geoengineering.

  6. Willingness of upstream and downstream resource managers to engage in compensation schemes for environmental services

    Directory of Open Access Journals (Sweden)

    Chapika Sangkapitux

    2009-04-01

    Full Text Available Providing compensation for agricultural conservation practices adopted by upstream farmers is still an alien concept in the Thai political context. The governance of common-pool natural resources, such as forest and water, has traditionally been under the control of powerful government line agencies, while the contribution of local communities to natural resource conservation have been hardly recognized by policy-makers. Drawing on a case study in Mae Sa watershed, Chiang Mai province, northern Thailand, this paper discusses the potential of developing compensation schemes in a socio-political context where upland farmers – mostly belonging to ethnic minority groups – tend to be considered a threat to the natural resource base rather than providers of environmental services. Based on data obtained from 371 households in the upstream communities and 151 households in the downstream communities of the watershed, upstream resource managers’ willingness to accept compensation for the conservation measures and downstream resource managers’ willingness to pay for water resource improvements were estimated through the use of choice experiments. Results from the study suggest that downstream resource managers would be willing to provide on average nearly 1% of their annual income for a substantial improvement of the quantity and quality of water resources, which could be achieved by compensating upstream farmers’ change of their agricultural systems towards more environment-friendly practices. Both willingness to pay of downstream respondents and willingness of upstream resource managers to accept compensation were positively correlated with age, education, participation in environmental conservation activities and previous experiences with droughts and/or erosion. The paper concludes that there is a clear potential for establishing compensation schemes for provision of environmental services in northern Thai watersheds. The important policy

  7. Design, Implementation, and Performance Evaluation of Efficient PMIPv6 Based Mobile Multicast Sender Support Schemes

    Directory of Open Access Journals (Sweden)

    Lili Wang

    2015-01-01

    Full Text Available Proxy Mobile IPv6 (PMIPv6 is proposed as a promising network-based mobility management protocol, which does not need any participation of mobile nodes. PMIPv6 does not support the multicast well and most of the current research concentrates on the mobile multicast receiver. However, the mobile multicast sender is also very important and challenging, which has not been addressed well. Therefore, in this paper we propose two efficient PMIPv6 based mobile multicast sender support schemes which are PMIP bidirectional tunneling (PMIP-BT and PMIP direct routing (PMIP-DR. In the PMIP-BT, the multicast traffic can be delivered through the PMIPv6 bidirectional tunnel, while, in the PMIP-DR, the multicast data can be transmitted via an optimized direct multicast routing. Both of them can support the multicast sender mobility transparently enabled in the PMIPv6 networks. We evaluate the performance of the proposed schemes by theoretical analysis, and the numerical results show that the proposed schemes have a better performance in terms of the signaling cost than the current schemes. Meanwhile, the proposed schemes are also implemented on the test bed, and the experimental results not only verify the validity and feasibility of our proposed schemes, but also conclude the different scenarios to which they are applicable.

  8. Essays on pension scheme design and risk management

    NARCIS (Netherlands)

    Cui, J.

    2009-01-01

    This dissertation deals with the optimal design of funded pension schemes and its welfare implications for participants. The first article illustrates the welfare gain of well organized intergenerational risk sharing within collective pension funds over the optimal individual benchmark. The second a

  9. Hepatic CT Image Query Based on Threshold-based Classification Scheme with Gabor Features

    Institute of Scientific and Technical Information of China (English)

    JIANG Li-jun; LUO Yong-zing; ZHAO Jun; ZHUANG Tian-ge

    2008-01-01

    Hepatic computed tomography (CT) images with Gabor function were analyzed.Then a thresholdbased classification scheme was proposed using Gabor features and proceeded with the retrieval of the hepatic CT images.In our experiments,a batch of hepatic CT images containing several types of CT findings was used and compared with the Zhao's image classification scheme,support vector machines (SVM) scheme and threshold-based scheme.

  10. Natural Resource Management Schemes as Entry Points for Integrated Landscape Approaches: Evidence from Ghana and Burkina Faso.

    Science.gov (United States)

    Foli, Samson; Ros-Tonen, Mirjam A F; Reed, James; Sunderland, Terry

    2017-04-20

    In recognition of the failures of sectoral approaches to overcome global challenges of biodiversity loss, climate change, food insecurity and poverty, scientific discourse on biodiversity conservation and sustainable development is shifting towards integrated landscape governance arrangements. Current landscape initiatives however very much depend on external actors and funding, raising the question of whether, and how, and under what conditions, locally embedded resource management schemes can serve as entry points for the implementation of integrated landscape approaches. This paper assesses the entry point potential for three established natural resource management schemes in West Africa that target landscape degradation with involvement of local communities: the Chantier d'Aménagement Forestier scheme encompassing forest management sites across Burkina Faso and the Modified Taungya System and community wildlife resource management initiatives in Ghana. Based on a review of the current literature, we analyze the extent to which design principles that define a landscape approach apply to these schemes. We found that the CREMA meets most of the desired criteria, but that its scale may be too limited to guarantee effective landscape governance, hence requiring upscaling. Conversely, the other two initiatives are strongly lacking in their design principles on fundamental components regarding integrated approaches, continual learning, and capacity building. Monitoring and evaluation bodies and participatory learning and negotiation platforms could enhance the schemes' alignment with integrated landscape approaches.

  11. Multifocus image fusion scheme based on nonsubsampled contourlet transform

    Science.gov (United States)

    Zhou, Xinxing; Wang, Dianhong; Duan, Zhijuan; Li, Dongming

    2011-06-01

    This paper proposes a novel multifocus image fusion scheme based on nonsubsampled contourlet transform (NSCT). The selection principles for different subband coefficients in NSCT domain are discussed in detail. In order to be consistent with the characteristics of the human visual system and improve the robustness of the fusion algorithm to the noise, the NSCT-DCT energy is first developed. Based on it, the clarity measure and bandpass energy contrast are defined and employed to motivate the pulse coupled neural networks (PCNN) for the fusion of lowpass and bandpass subbands, respectively. The performance of the proposed fusion scheme is assessed by experiments and the results demonstrate that the algorithm proposed in the paper compares favorably to wavelet-based, contourlet-based and NSCTbased fusion algorithms in terms of visual appearances and objective criterion.

  12. Computerized scheme for duplicate checking of bibliographic data bases

    Energy Technology Data Exchange (ETDEWEB)

    Giles, C.A.; Brooks, A.A.; Doszkocs, T.; Hummel, D.J.

    1976-08-01

    A technique for the automatic identification of duplicate documents within large bibliographic data bases has been designed and tested with encouraging results. The procedure is based on the generation and comparison of significant elements compressed from existing document descriptions. Problems arising from inconsistencies in editorial style and data base formats and from discrepancies in spelling, punctuation, translation and transliteration schemes are discussed; one method for circumventing ambiguities and errors of this type is proposed. The generalized computer program employs a key-making, sorting, weighting, and summation scheme for the detection of duplicates and, according to preliminary findings, achieves this objective with a high degree of accuracy. Sample results from five large data bases suggest that this automatic system performs as effectively as manual techniques.

  13. Color Based Authentication Scheme for Publically Disclosable Entities

    Directory of Open Access Journals (Sweden)

    A. S. Syed Shahul Hameed

    2015-01-01

    Full Text Available Traditional password authentication system are not strong enough to cope up with the current age of cybercrime. It’s high time that new password authentication schemes are explored and studied. This paper aims to provide an authentication system based on color recognition which would provide a way to encrypt both the username and password. The Color based authentication system would provide an efficient way to encrypt account details for sensitive applications like defense and banking.

  14. A New Symbol Synchronization Scheme for Cyclic Prefix Based Systems

    Institute of Scientific and Technical Information of China (English)

    KUANG Yu-jun; TENG Yong; YIN Chang-chuan; HAO Jian-jun; YUE Guang-xin

    2003-01-01

    This contribution proposes a new symbol synchronization scheme for cyclic prefix based modulation systems, which is disclosed in Ref.[16]. The proposed algorithm involves two steps. By using short-time Fourier transform, ISI-free intervals are estimated from time-frequency spectrum of the received signal, and then an optimum symbol start time is obtained. Computer simulation results show that the algorithm is very robust, and outperforms those based upon time-domain correlations.

  15. Image classification based on scheme of principal node analysis

    Science.gov (United States)

    Yang, Feng; Ma, Zheng; Xie, Mei

    2016-11-01

    This paper presents a scheme of principal node analysis (PNA) with the aim to improve the representativeness of the learned codebook so as to enhance the classification rate of scene image. Original images are normalized into gray ones and the scale-invariant feature transform (SIFT) descriptors are extracted from each image in the preprocessing stage. Then, the PNA-based scheme is applied to the SIFT descriptors with iteration and selection algorithms. The principal nodes of each image are selected through spatial analysis of the SIFT descriptors with Manhattan distance (L1 norm) and Euclidean distance (L2 norm) in order to increase the representativeness of the codebook. With the purpose of evaluating the performance of our scheme, the feature vector of the image is calculated by two baseline methods after the codebook is constructed. The L1-PNA- and L2-PNA-based baseline methods are tested and compared with different scales of codebooks over three public scene image databases. The experimental results show the effectiveness of the proposed scheme of PNA with a higher categorization rate.

  16. Optimal Compensation for Fund Managers of Uncertain Type: The Information Advantages of Bonus Schemes

    OpenAIRE

    Alexander Stremme

    1999-01-01

    Performance-sensitivity of compensation schemes for portfolio managers is well explained by classic principal-agent theory as a device to provide incentives for managers to exert effort or bear the cost of acquiring information. However, the majority of compensation packages observed in reality display in addition a fair amount of convexity in the form of performance-related bonus schemes. While convex contracts may be explained by principal-agent theory in some rather specific situations, th...

  17. Toxicological mass disaster management - a hospital deployment scheme.

    Science.gov (United States)

    Baniel, J; Ram, Z; Kami, A; Schindel, D

    1986-09-01

    Toxicological mass disasters have occurred frequently in past years and constitute a permanent threat in urban areas. From the standpoint of hospital planning, special consideration is required to treat a large number of poisoned casualties in a relatively short period. Several unique medical aspects characterize toxicological mass disasters: casualties present a single disease entity with many "borderline" cases, most medical personnel are unfamiliar with the problem and casualties present a potential contamination hazard to the hospital. A hospital deployment scheme is presented recommending Decontamination, Triage and simple Treatment Algorithms to meet the medical and organizational challenge of such a mass casualty situation. A further specific deployment scheme for treatment of organophosphorus agents poisoning is described to illustrate the principles presented.

  18. A Cartesian grid-based unified gas kinetic scheme

    Science.gov (United States)

    Chen, Songze; Xu, Kun

    2014-12-01

    A Cartesian grid-based unified gas kinetic scheme is developed. In this approach, any oriented boundary in a Cartesian grid is represented by many directional boundary points. The numerical flux is evaluated on each boundary point. Then, a boundary flux interpolation method (BFIM) is constructed to distribute the boundary effect to the flow evolution on regular Cartesian grid points. The BFIM provides a general strategy to implement any kind of boundary condition on Cartesian grid. The newly developed technique is implemented in the unified gas kinetic scheme, where the scheme is reformulated into a finite difference format. Several typical test cases are simulated with different geometries. For example, the thermophoresis phenomenon for a plate with infinitesimal thickness immersed in a rarefied flow environment is calculated under different orientations on the same Cartesian grid. These computational results validate the BFIM in the unified scheme for the capturing of different thermal boundary conditions. The BFIM can be extended to the moving boundary problems as well.

  19. NUMERICAL COMPUTATIONS OF CO-EXISTING SUPER-CRITICAL AND SUB-CRITICAL FLOWS BASED UPON CRD SCHEMES

    Science.gov (United States)

    Horie, Katsuya; Okamura, Seiji; Kobayashi, Yusuke; Hyodo, Makoto; Hida, Yoshihisa; Nishimoto, Naoshi; Mori, Akio

    Stream flows in steep gradient bed form complicating flow configurations, where co-exist super-critical and sub-critical flows. Computing numerically such flows are the key to successful river management. This study applied CRD schemes to 1D and 2D stream flow computations and proposed genuine ways to eliminate expansion shock waves. Through various cases of computing stream flows conducted, CRD schemes showed that i) conservativeness of discharge and accuracy of four significant figures are ensured, ii) artificial viscosity is not explicitly used for computational stabilization, and thus iii) 1D and 2D computations based upon CRD schemes are applicable to evaluating complicating stream flows for river management.

  20. Enhancing Community Detection By Affinity-based Edge Weighting Scheme

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Andy [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Sanders, Geoffrey [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Henson, Van [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Vassilevski, Panayot [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-10-05

    Community detection refers to an important graph analytics problem of finding a set of densely-connected subgraphs in a graph and has gained a great deal of interest recently. The performance of current community detection algorithms is limited by an inherent constraint of unweighted graphs that offer very little information on their internal community structures. In this paper, we propose a new scheme to address this issue that weights the edges in a given graph based on recently proposed vertex affinity. The vertex affinity quantifies the proximity between two vertices in terms of their clustering strength, and therefore, it is ideal for graph analytics applications such as community detection. We also demonstrate that the affinity-based edge weighting scheme can improve the performance of community detection algorithms significantly.

  1. A Color Image Digital Watermarking Scheme Based on SOFM

    CERN Document Server

    Anitha, J

    2011-01-01

    Digital watermarking technique has been presented and widely researched to solve some important issues in the digital world, such as copyright protection, copy protection and content authentication. Several robust watermarking schemes based on vector quantization (VQ) have been presented. In this paper, we present a new digital image watermarking method based on SOFM vector quantizer for color images. This method utilizes the codebook partition technique in which the watermark bit is embedded into the selected VQ encoded block. The main feature of this scheme is that the watermark exists both in VQ compressed image and in the reconstructed image. The watermark extraction can be performed without the original image. The watermark is hidden inside the compressed image, so much transmission time and storage space can be saved when the compressed data are transmitted over the Internet. Simulation results demonstrate that the proposed method has robustness against various image processing operations without sacrif...

  2. Security of a biometric identity-based encryption scheme

    CERN Document Server

    Tian, Miaomiao; Huang, Liusheng

    2011-01-01

    Biometric identity-based encryption (Bio-IBE) is a kind of fuzzy identity-based encryption (fuzzy IBE) where a ciphertext encrypted under an identity w' can be decrypted using a secret key corresponding to the identity w which is close to w' as measured by some metric. Recently, Yang et al. proposed a constant-size Bio-IBE scheme and proved that it is secure against adaptive chosen-ciphertext attack (CCA2) in the random oracle model. Unfortunately, in this paper, we will show that their Bio-IBE scheme is even not chosen-plaintext secure. Specifically, user w using his secret key is able to decrypt any ciphertext encrypted under an identity w' even though w is not close to w'.

  3. A new support vector machine based multiuser detection scheme

    Institute of Scientific and Technical Information of China (English)

    WANG Yong-jian; ZHAO Hong-lin

    2008-01-01

    In order to suppress the multiple access interference(MAI)in 3G,which limits the capacity of a CDMA communication system,a fast relevance vector machine(FRVM)is employed in the muhinser detection (MUD)scheme.This method aims to overcome the shortcomings of many ordinary support vector machine (SVM)based MUD schemes,such as the long training time and the inaccuracy of the decision data,and enhance the performance of a CDMA communication system.Computer simulation results demonstrate that the proposed FRVM based muhiuser detection has lower bit error rate,costs short training time,needs fewer kernel functions and possesses better near-far resistance.

  4. Australian managed entry scheme: a new manageable process for the reimbursement of new medicines?

    Science.gov (United States)

    Wonder, Michael; Backhouse, Martin E; Sullivan, Sean D

    2012-05-01

    The global prescription medicines industry argues that it needs high prices for new medicines to meet ever-increasing development costs. While many payers are prepared to pay high prices if they represent good value for money, they first need to feel assured that the value for money estimates are robust. Insofar as new medicines enter the market with limited and uncertain data relating to their performance in normal clinical practice, the value for money case for some medicines may well be driven largely by assumptions than by empirical evidence. The concern to manufacturers is that payers respond to this uncertainty by listing the product at a lower price (which may not satisfy the producer) or not listing the product until more evidence is available (which may not satisfy clinicians and patients). Is there a solution that will satisfy all key stakeholders? Will clinicians and patients continue to have timely access to new medicines and will payers have sustainable reimbursement systems? Will the industry continue to be rewarded with high prices for new medicines so long as they represent good value for money? In 2011, the Australian Government introduced a managed entry scheme whereby the Pharmaceutical Benefits Advisory Committee will recommend the listing of a new medicine at a price justified by the existing evidence, pending the availability of more conclusive evidence of cost-effectiveness to support its continued listing at a higher price. This commentary examines the Australian Government's managed entry scheme and issues that are likely to arise from its implementation.

  5. Kinetic energy decomposition scheme based on information theory.

    Science.gov (United States)

    Imamura, Yutaka; Suzuki, Jun; Nakai, Hiromi

    2013-12-15

    We proposed a novel kinetic energy decomposition analysis based on information theory. Since the Hirshfeld partitioning for electron densities can be formulated in terms of Kullback-Leibler information deficiency in information theory, a similar partitioning for kinetic energy densities was newly proposed. The numerical assessments confirm that the current kinetic energy decomposition scheme provides reasonable chemical pictures for ionic and covalent molecules, and can also estimate atomic energies using a correction with viral ratios.

  6. Functions and Design Scheme of Tibet High Altitude Test Base

    Institute of Scientific and Technical Information of China (English)

    Yu Yongqing; Guo Jian; Yin Yu; Mao Yan; Li Guangfan; Fan Jianbin; Lu Jiayu; Su Zhiyi; Li Peng; Li Qingfeng; Liao Weiming; Zhou Jun

    2010-01-01

    @@ The functional orientation of the Tibet High Altitude Test Base, subordinated to the State Grid Corporation of China (SGCC), is to serve power transmission projects in high altitude areas, especially to provide technical support for southwestern hydropower delivery projects by UHVDC transmission and Qinghai-Tibet grid interconnection project. This paper presents the matters concerned during siting and planning, functions,design scheme, the main performances and parameters of the test facilities, as well as the tests and research tasks already carried out.

  7. Revisiting Quantum Authentication Scheme Based on Entanglement Swapping

    Science.gov (United States)

    Naseri, Mosayeb

    2016-05-01

    The crucial issue of quantum communication protocol is its security. In this paper, the security of the Quantum Authentication Scheme Based on Entanglement Swapping proposed by Penghao et al. (Int J Theor Phys., doi: 10.1007/s10773-015-2662-7) is reanalyzed. It is shown that the original does not complete the task of quantum authentication and communication securely. Furthermore a simple improvement on the protocol is proposed.

  8. Functions and Design Scheme of Tibet High Altitude Test Base

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The functional orientation of the Tibet High Altitude Test Base, subordinated to the State Grid Corporation of China (SGCC), is to serve power transmission projects in high altitude areas, especially to provide technical support for southwestern hydropower delivery projects by UHVDC transmission and Qinghai-Tibet grid interconnection project. This paper presents the matters concerned during siting and planning, functions, design scheme, the main performances and parameters of the test facilities, as well as...

  9. Reducing Communication Overhead For Authentication Using Self Contained Public Key Management Scheme In MANET

    Directory of Open Access Journals (Sweden)

    Gundala Swathi

    2013-06-01

    Full Text Available In the past few years, we have seen a rapid increase in important application fields of Mobile ad-hoc networks (MANET. Hence, many industrial and academic researchers have been conducted. Because, these applications are closely related to human beings and their physical environment, the usage of MANET on a large scale depends on whether we can provide proper dependability. Particularly, security is the most important issue in MANET because of the limitation in resources. Management of keys is the most necessary activity for providing security for the network. MANETs have resource limitations. Thus using public-key based solutions is not feasible. Thus, we use symmetric key establishment. In this paper, a key management scheme which is self contained and public is represented.This scheme achieves near zero communication overhead while providing security services. Cryptographic keys in small numbers are inputted at all nodes prior to the deployment in network. Mathematical Combinations of pairs of keys, both public and private is used for better utilization of storage space. This means a combination of more than one key pair is utilized by nodes for the encryption and the decryption of messages. A secure communication algorithm for forwarding the packets in MANET is also proposed.

  10. Information processing schemes based on monolayer protected metallic nanoclusters.

    Science.gov (United States)

    Cervera, Javier; Mafé, Salvador

    2011-09-01

    Nanostructures are potentially useful as building blocks to complement future electronics because of their high versatility and packing densities. The fabrication and characterization of particular nanostructures and the use of new theoretical tools to describe their properties are receiving much attention. However, the integration of these individual systems into general schemes that could perform simple tasks is also necessary because modern electronics operation relies on the concerted action of many basic units. We review here new conceptual schemes that can allow information processing with ligand or monolayer protected metallic nanoclusters (MPCs) on the basis of the experimentally demonstrated and theoretically described electrical characteristics of these nanostructures. In particular, we make use of the tunnelling current through a metallic nanocluster attached to the electrodes by ligands. The nanostructure is described as a single electron transistor (SET) that can be gated by an external potential. This fact permits exploiting information processing schemes in approximately defined arrays of MPCs. These schemes include: (i) binary, multivalued, and reversible logic gates; (ii) an associative memory and a synchronization circuit; and (iii) two signal processing nanodevices based on parallel arrays of MPCs and nanoswitches. In each case, the practical operation of the nanodevice is based on the SET properties of MPCs reported experimentally. We examine also some of the practical problems that should be addressed in future experimental realizations: the stochastic nature of the electron tunnelling, the relatively low operation temperatures, and the limited reliability caused by the weak signals involved and the nanostructure variability. The perspectives to solve these problems are based on the potentially high degree of scalability of the nanostructures.

  11. Hierarchical adaptation scheme for multiagent data fusion and resource management in situation analysis

    Science.gov (United States)

    Benaskeur, Abder R.; Roy, Jean

    2001-08-01

    Sensor Management (SM) has to do with how to best manage, coordinate and organize the use of sensing resources in a manner that synergistically improves the process of data fusion. Based on the contextual information, SM develops options for collecting further information, allocates and directs the sensors towards the achievement of the mission goals and/or tunes the parameters for the realtime improvement of the effectiveness of the sensing process. Conscious of the important role that SM has to play in modern data fusion systems, we are currently studying advanced SM Concepts that would help increase the survivability of the current Halifax and Iroquois Class ships, as well as their possible future upgrades. For this purpose, a hierarchical scheme has been proposed for data fusion and resource management adaptation, based on the control theory and within the process refinement paradigm of the JDL data fusion model, and taking into account the multi-agent model put forward by the SASS Group for the situation analysis process. The novelty of this work lies in the unified framework that has been defined for tackling the adaptation of both the fusion process and the sensor/weapon management.

  12. QoS Based Capacity Enhancement for WCDMA Network with Coding Scheme

    CERN Document Server

    Ayyappan, K; 10.5121/vlsic.2010.1102

    2010-01-01

    The wide-band code division multiple access (WCDMA) based 3G and beyond cellular mobile wireless networks are expected to provide a diverse range of multimedia services to mobile users with guaranteed quality of service (QoS). To serve diverse quality of service requirements of these networks it necessitates new radio resource management strategies for effective utilization of network resources with coding schemes. Call admission control (CAC) is a significant component in wireless networks to guarantee quality of service requirements and also to enhance the network resilience. In this paper capacity enhancement for WCDMA network with convolutional coding scheme is discussed and compared with block code and without coding scheme to achieve a better balance between resource utilization and quality of service provisioning. The model of this network is valid for the real-time (RT) and non-real-time (NRT) services having different data rate. Simulation results demonstrate the effectiveness of the network using co...

  13. Obfuscated RSUs Vector Based Signature Scheme for Detecting Conspiracy Sybil Attack in VANETs

    Directory of Open Access Journals (Sweden)

    Xia Feng

    2017-01-01

    Full Text Available Given the popularity of vehicular Ad hoc networks (VANETs in traffic management, a new challenging issue comes into traffic safety, that is, security of the networks, especially when the adversary breaks defence. Sybil attack, for example, is a potential security threat through forging several identities to carry out attacks in VANETs. At this point, the paper proposed a solution named DMON that is a Sybil attack detection method with obfuscated neighbor relationship of Road Side Units (RSUs. DMON presents a ring signature based identification scheme and replaces vehicles’ identities with their trajectory for the purpose of anonymity. Furthermore, the neighbor relationship of RSUs is obfuscated to achieve privacy preserving of locations. The proposed scheme has been formally proved in the views of security and performance. Simulation has also been implemented to validate the scheme, in which the findings reveal the lower computational overhead and higher detection rate comparing with other related solutions.

  14. A Novel User Authentication Scheme Based on QR-Code

    Directory of Open Access Journals (Sweden)

    Kuan-Chieh Liao

    2010-08-01

    Full Text Available User authentication is one of the fundamental procedures to ensure secure communications and share system resources over an insecure public network channel.  Thus, a simple and efficient authentication mechanism is required for securing the network system in the real environment. In general, the password-based authentication mechanism provides the basic capability to prevent unauthorized access. Especially, the purpose of the one-time password is to make it more difficult to gain unauthorized access to restricted resources. Instead of using the password file as conventional authentication systems, many researchers have devoted to implement various one-time password schemes using smart cards, time-synchronized token or short message service in order to reduce the risk of tampering and maintenance cost.  However, these schemes are impractical because of the far from ubiquitous hardware devices or the infrastructure requirements. To remedy these weaknesses, the attraction of the QR-code technique can be introduced into our one-time password authentication protocol. Not the same as before, the proposed scheme based on QR code not only eliminates the usage of the password verification table, but also is a cost effective solution since most internet users already have mobile phones. For this reason, instead of carrying around a separate hardware token for each security domain, the superiority of handiness benefit from the mobile phone makes our approach more practical and convenient.

  15. Energy Efficient Cluster Based Scheduling Scheme for Wireless Sensor Networks.

    Science.gov (United States)

    Janani, E Srie Vidhya; Kumar, P Ganesh

    2015-01-01

    The energy utilization of sensor nodes in large scale wireless sensor network points out the crucial need for scalable and energy efficient clustering protocols. Since sensor nodes usually operate on batteries, the maximum utility of network is greatly dependent on ideal usage of energy leftover in these sensor nodes. In this paper, we propose an Energy Efficient Cluster Based Scheduling Scheme for wireless sensor networks that balances the sensor network lifetime and energy efficiency. In the first phase of our proposed scheme, cluster topology is discovered and cluster head is chosen based on remaining energy level. The cluster head monitors the network energy threshold value to identify the energy drain rate of all its cluster members. In the second phase, scheduling algorithm is presented to allocate time slots to cluster member data packets. Here congestion occurrence is totally avoided. In the third phase, energy consumption model is proposed to maintain maximum residual energy level across the network. Moreover, we also propose a new packet format which is given to all cluster member nodes. The simulation results prove that the proposed scheme greatly contributes to maximum network lifetime, high energy, reduced overhead, and maximum delivery ratio.

  16. Image integrity authentication scheme based on fixed point theory.

    Science.gov (United States)

    Li, Xu; Sun, Xingming; Liu, Quansheng

    2015-02-01

    Based on the fixed point theory, this paper proposes a new scheme for image integrity authentication, which is very different from digital signature and fragile watermarking. By the new scheme, the sender transforms an original image into a fixed point image (very close to the original one) of a well-chosen transform and sends the fixed point image (instead of the original one) to the receiver; using the same transform, the receiver checks the integrity of the received image by testing whether it is a fixed point image and locates the tampered areas if the image has been modified during the transmission. A realization of the new scheme is based on Gaussian convolution and deconvolution (GCD) transform, for which an existence theorem of fixed points is proved. The semifragility is analyzed via commutativity of transforms, and three commutativity theorems are found for the GCD transform. Three iterative algorithms are presented for finding a fixed point image with a few numbers of iterations, and for the whole procedure of image integrity authentication; a fragile authentication system and a semifragile one are separately built. Experiments show that both the systems have good performance in transparence, fragility, security, and tampering localization. In particular, the semifragile system can perfectly resist the rotation by a multiple of 90° flipping and brightness attacks.

  17. An image encryption scheme based on quantum logistic map

    Science.gov (United States)

    Akhshani, A.; Akhavan, A.; Lim, S.-C.; Hassan, Z.

    2012-12-01

    The topic of quantum chaos has begun to draw increasing attention in recent years. While a satisfactory definition for it is not settled yet in order to differentiate between its classical counterparts. Dissipative quantum maps can be characterized by sensitive dependence on initial conditions, like classical maps. Considering this property, an implementation of image encryption scheme based on the quantum logistic map is proposed. The security and performance analysis of the proposed image encryption is performed using well-known methods. The results of the reliability analysis are encouraging and it can be concluded that, the proposed scheme is efficient and secure. The results of this study also suggest application of other quantum maps such as quantum standard map and quantum baker map in cryptography and other aspects of security and privacy.

  18. About the Key Escrow Properties of Identity Based Encryption Schemes

    Directory of Open Access Journals (Sweden)

    Ruxandra Olimid

    2012-09-01

    Full Text Available IBE (Identity Based Encryption represents a type of public key encryption that allows a party to encrypt a message using the recipient’s identity as public key. The private keys needed for decryption are generated and distributed to each party by a KGC (Key Generation Center. The existence of such an entity in an IBE scheme allows access to the encrypted information for other parties other than the intended recipient by construction: the KGC or any other entity that receives the cryptographic keys from the KGC may perform decryption. A system that permits other parties to have access to the private keys of the users is said to have key escrow abilities. The paper performs a brief analysis of the key escrow properties of IBE schemes and gives a practical example of communication protocol that improves the key escrow capabilities.

  19. An Opportunistic Relaying Selection Scheme Based on Relay Fairness

    Directory of Open Access Journals (Sweden)

    Ting An

    2013-07-01

    Full Text Available Opportunistic relaying scheme is a single cooperative relay selection method based on Channel State Information. However, the failure probability of the best relay selection may become unacceptable when the number of relays increases. Although most of the existing solutions can reduce the failure probability of relay selection, they ignore the fairness of the relay selection. In order to improve the fairness of the relay selection without affecting the failure probability of the best relay selection, we propose a modified practical best relay selection scheme in this paper,  and by introducing proportional fair algorithm, the relay timer will be given a smaller correlation coefficient. The proposed method makes the probability of selection be improved. In the light of defined fairness factor, the relay fairness is represented. Simulation results show that the new algorithm can improve the fairness of the relay selection on the basis of maintaining the original failure probability of relay selection.

  20. Prediction-based association control scheme in dense femtocell networks

    Science.gov (United States)

    Pham, Ngoc-Thai; Huynh, Thong; Hwang, Won-Joo; You, Ilsun; Choo, Kim-Kwang Raymond

    2017-01-01

    The deployment of large number of femtocell base stations allows us to extend the coverage and efficiently utilize resources in a low cost manner. However, the small cell size of femtocell networks can result in frequent handovers to the mobile user, and consequently throughput degradation. Thus, in this paper, we propose predictive association control schemes to improve the system’s effective throughput. Our design focuses on reducing handover frequency without impacting on throughput. The proposed schemes determine handover decisions that contribute most to the network throughput and are proper for distributed implementations. The simulation results show significant gains compared with existing methods in terms of handover frequency and network throughput perspective. PMID:28328992

  1. An improved biometrics-based remote user authentication scheme with user anonymity.

    Science.gov (United States)

    Khan, Muhammad Khurram; Kumari, Saru

    2013-01-01

    The authors review the biometrics-based user authentication scheme proposed by An in 2012. The authors show that there exist loopholes in the scheme which are detrimental for its security. Therefore the authors propose an improved scheme eradicating the flaws of An's scheme. Then a detailed security analysis of the proposed scheme is presented followed by its efficiency comparison. The proposed scheme not only withstands security problems found in An's scheme but also provides some extra features with mere addition of only two hash operations. The proposed scheme allows user to freely change his password and also provides user anonymity with untraceability.

  2. A two encryption mechanisms based key management scheme of ZigBee wireless sensor networks%基于两种加密机制的ZigBee网络密钥管理方案

    Institute of Scientific and Technical Information of China (English)

    潘金秋; 赵华伟; 徐如志; 黄太波

    2011-01-01

    The main negatives of a ZigBee wireless sensor network are limited computing ability, storage capacity and self resources. Network security is one of the main restrictions to its rapid development. It is therefore quite significant to guarantee its security. Key management is the basis for such security. This paper statistically analyzes the relationship between network size and the number of polygon vertices with the relationship among vertices, sides and diagonals of a polygon and then presents a novel key management scheme. This scheme has higher security but lower storage and computing capability requirements, so it reduces the requirement for network resources and can guide further research on network security.%网络的安全性问题是制约ZigBee无线传感网络飞速发展的主要原因。密钥管理是保证网络安全性的基础,本文利用多边形顶点和边及对角线数目的关系,对网络大小和多边形顶点数目的关系进行统计分析,提出一种密钥管理方案,安全性能较高,对存储和计算的要求较低,节省了保证网络所需要的资源,对进一步研究ZigBee网络安全具有理论指导意义。

  3. Knowledge and uptake of community-based health insurance scheme among residents of Olowora, Lagos

    Directory of Open Access Journals (Sweden)

    O A Ibukun

    2013-01-01

    Full Text Available Background and Objective: The informal sector population in developing nations has low health coverage from Community Based Health Insurance (CBHI and problems such as limited awareness about the potential impact of prepayment health financing and the limited resources to finance health care can impede success. This study assessed the community based health insurance scheme uptake and determinants in Olowora, Lagos State. Methods: This was a descriptive cross sectional study carried out in July 2010 in all households of 12 out of 41 streets in Olowora,by multistage sampling. Four hundred and sixteen interviewer-administered questionnaires were completed and returned. Analysis was by Epi- info version 3.5.1 software. Results: Although 75.5% of respondents were aware of the Community Health Insurance scheme at Olowora, just about half (49.5% of them had good knowledge of the scheme. A substantial proportion (44.2% of respondents did not believe in contributing money for illness yet to come, and majority (72.3% of such respondents prefers payment for health care when ill. While about half (53% of respondentshad enrolled into the community health insurance scheme, 45.6% of those who had not enrolled were not aware of the scheme. Lack of money was the main reason (51.5% why some enrollees had defaulted. Conclusion: The study identified information gaps and poor understanding of the scheme as well as poverty as factors that have negatively affected uptake. The scheme management has to re-evaluate its sensitization programmes, and also strengthen marketing strategies with special emphasis on the poor.

  4. Target searching based on modified implicit ROI encoding scheme

    Institute of Scientific and Technical Information of China (English)

    Bai Xu; Zhang Zhongzhao

    2008-01-01

    An EBCOT-based method is proposed to reduce the priority of background coefficients in the ROI code block without compromising algorithm complexity.The region of interest is encoded to a higher quality level than background,and the target searching time in video-guided penetrating missile can be shortened.Three kinds of coding schemes based on EBCOT are discussed.Experimental results demonstrate that the proposed method shows higher compression efficiency,lower complexity,and good reconstructed ROI image quality in the lower channel capacity.

  5. Biometrics based authentication scheme for session initiation protocol.

    Science.gov (United States)

    Xie, Qi; Tang, Zhixiong

    2016-01-01

    Many two-factor challenge-response based session initiation protocol (SIP) has been proposed, but most of them are vulnerable to smart card stolen attacks and password guessing attacks. In this paper, we propose a novel three-factor SIP authentication scheme using biometrics, password and smart card, and utilize the pi calculus-based formal verification tool ProVerif to prove that the proposed protocol achieves security and authentication. Furthermore, our protocol is highly efficient when compared to other related protocols.

  6. Multiresolution image fusion scheme based on fuzzy region feature

    Institute of Scientific and Technical Information of China (English)

    LIU Gang; JING Zhong-liang; SUN Shao-yuan

    2006-01-01

    This paper proposes a novel region based image fusion scheme based on multiresolution analysis. The low frequency band of the image multiresolution representation is segmented into important regions, sub-important regions and background regions. Each feature of the regions is used to determine the region's degree of membership in the multiresolution representation,and then to achieve multiresolution representation of the fusion result. The final image fusion result can be obtained by using the inverse multiresolution transform. Experiments showed that the proposed image fusion method can have better performance than existing image fusion methods.

  7. Dynamic Symmetric Key Mobile Commerce Scheme Based on Self-Verified Mechanism

    Directory of Open Access Journals (Sweden)

    Jiachen Yang

    2014-01-01

    Full Text Available In terms of the security and efficiency of mobile e-commerce, the authors summarized the advantages and disadvantages of several related schemes, especially the self-verified mobile payment scheme based on the elliptic curve cryptosystem (ECC and then proposed a new type of dynamic symmetric key mobile commerce scheme based on self-verified mechanism. The authors analyzed the basic algorithm based on self-verified mechanisms and detailed the complete transaction process of the proposed scheme. The authors analyzed the payment scheme based on the security and high efficiency index. The analysis shows that the proposed scheme not only meets the high efficiency of mobile electronic payment premise, but also takes the security into account. The user confirmation mechanism at the end of the proposed scheme further strengthens the security of the proposed scheme. In brief, the proposed scheme is more efficient and practical than most of the existing schemes.

  8. KALwEN: a new practical and interoperable key management scheme for body sensor networks

    NARCIS (Netherlands)

    Law, Yee Wei; Moniava, Giorgi; Gong, Zheng; Hartel, Pieter; Palaniswami, Marimuthu

    2010-01-01

    Key management is the pillar of a security architecture. Body sensor networks (BSNs) pose several challenges–some inherited from wireless sensor networks (WSNs), some unique to themselves–that require a new key management scheme to be tailor-made. The challenge is taken on, and the result is KALwEN,

  9. Demand response scheme based on lottery-like rebates

    KAUST Repository

    Schwartz, Galina A.

    2014-08-24

    In this paper, we develop a novel mechanism for reducing volatility of residential demand for electricity. We construct a reward-based (rebate) mechanism that provides consumers with incentives to shift their demand to off-peak time. In contrast to most other mechanisms proposed in the literature, the key feature of our mechanism is its modest requirements on user preferences, i.e., it does not require exact knowledge of user responsiveness to rewards for shifting their demand from the peak to the off-peak time. Specifically, our mechanism utilizes a probabilistic reward structure for users who shift their demand to the off-peak time, and is robust to incomplete information about user demand and/or risk preferences. We approach the problem from the public good perspective, and demonstrate that the mechanism can be implemented via lottery-like schemes. Our mechanism permits to reduce the distribution losses, and thus improve efficiency of electricity distribution. Finally, the mechanism can be readily incorporated into the emerging demand response schemes (e.g., the time-of-day pricing, and critical peak pricing schemes), and has security and privacy-preserving properties.

  10. Periodic Sweep Coverage Scheme Based on Periodic Vehicle Routing Problem

    Directory of Open Access Journals (Sweden)

    Li Shu

    2014-03-01

    Full Text Available We provide a sweep coverage algorithm for routing mobile sensors that communicate with a central data sink. This algorithm improves on its predecessors by reducing the number of unnecessary scans when different points of interest (POIs have different requirements for the time interval within which they must be scanned (sweep period. Most sweep coverage algorithms seek to minimize the number of sensors required to cover a given collection of POIs. When POIs have different sweep period requirements, existing algorithms will produce solutions in which sensors visit some POIs much more frequently than is necessary. We define this as the POI Over-Coverage problem. In order to address this problem we develop a Periodic Sweep Coverage (PSC scheme based on a well-known solution to the Periodic Vehicle Routing Problem (PVRP. Our algorithm seeks a route for the mobile sensors that minimizes the number of unnecessary visits to each POI. To verify and test the proposed scheme we implemented a C++ simulation and ran scenarios with a variety of POI topologies (number and distribution of the POIs and the speed at which sensors could travel. The simulation results show that the PSC algorithm outperforms other sweep coverage algorithms such as CSweep and Vehicle Routing Problem Sweep Coverage (VRPSC on both the average number of sensors in a solution and in the computational time required to find a solution. Our results also demonstrate that the PSC scheme is more suitable for the sweep coverage scenarios in which higher speed mobile sensors are used.

  11. Arbitrated quantum signature scheme based on reusable key

    Science.gov (United States)

    Yu, ChaoHua; Guo, GongDe; Lin, Song

    2014-11-01

    An arbitrated quantum signature scheme without using entangled states is proposed. In the scheme, by employing a classical hash function and random numbers, the secret keys of signer and receiver can be reused. It is shown that the proposed scheme is secure against several well-known attacks. Specifically, it can stand against the receiver's disavowal attack. Moreover, compared with previous relevant arbitrated quantum signature schemes, the scheme proposed has the advantage of less transmission complexity.

  12. Arbitrated quantum signature scheme based on reusable key

    Institute of Scientific and Technical Information of China (English)

    YU ChaoHua; GUO GongDe; LIN Song

    2014-01-01

    An arbitrated quantum signature scheme without using entangled states is proposed.In the scheme,by employing a classical hash function and random numbers,the secret keys of signer and receiver can be reused.It is shown that the proposed scheme is secure against several well-known attacks.Specifically,it can stand against the receiver's disavowal attack.Moreover,compared with previous relevant arbitrated quantum signature schemes,the scheme proposed has the advantage of less transmission complexity.

  13. A secure biometrics-based authentication scheme for telecare medicine information systems.

    Science.gov (United States)

    Yan, Xiaopeng; Li, Weiheng; Li, Ping; Wang, Jiantao; Hao, Xinhong; Gong, Peng

    2013-10-01

    The telecare medicine information system (TMIS) allows patients and doctors to access medical services or medical information at remote sites. Therefore, it could bring us very big convenient. To safeguard patients' privacy, authentication schemes for the TMIS attracted wide attention. Recently, Tan proposed an efficient biometrics-based authentication scheme for the TMIS and claimed their scheme could withstand various attacks. However, in this paper, we point out that Tan's scheme is vulnerable to the Denial-of-Service attack. To enhance security, we also propose an improved scheme based on Tan's work. Security and performance analysis shows our scheme not only could overcome weakness in Tan's scheme but also has better performance.

  14. 基于项目驱动的研究生创新团队管理机制%Graduate Students Innovation Team Management Scheme Based on Project-Driven

    Institute of Scientific and Technical Information of China (English)

    刘媛妮; 唐红

    2013-01-01

      项目驱动型创新团队是一种新的创新团队驱动方式,目前在项目的持续性,成员的流动性方面还存在诸多管理方面的问题。本文从项目管理、团队管理以及成员管理三个方面提出了项目驱动型研究生创新团队管理过程中应注意的问题和基本解决措施。%Project-driven innovation team is a new innovative team-driven approach. Currently, there are many management issues in the sustainability of the project, members of the liquidi-ty. This paper pointed out the problems and the corresponding solutions from three aspects of the management schemes about graduate students innovation team.

  15. AN AGENT BASED TRANSACTION PROCESSING SCHEME FOR DISCONNECTED MOBILE NODES

    Directory of Open Access Journals (Sweden)

    J.L. Walter Jeyakumar

    2010-12-01

    Full Text Available We present a mobile transaction framework in which mobile users can share data which is stored in the cache of a mobile agent. This mobile agent is a special mobile node which coordinates the sharing process. The proposed framework allows mobile affiliation work groups to be formed dynamically with a mobile agent and mobile hosts. Using short range wireless communication technology, mobile users can simultaneously access the data from the cache of the mobile agent. The data Access Manager module at the mobile agent enforces concurrency control using cache invalidation technique. This model supports disconnected mobile computing allowing mobile agent to move along with the Mobile Hosts. The proposed Transaction frame work has been simulated in Java 2 and performance of this scheme is compared with existing frame works.

  16. A New Images Hiding Scheme Based on Chaotic Sequences

    Institute of Scientific and Technical Information of China (English)

    LIU Nian-sheng; GUO Dong-hui; WU Bo-xi; Parr G

    2005-01-01

    We propose a data hidding technique in a still image. This technique is based on chaotic sequence in the transform domain of covert image. We use different chaotic random sequences multiplied by multiple sensitive images, respectively, to spread the spectrum of sensitive images. Multiple sensitive images are hidden in a covert image as a form of noise. The results of theoretical analysis and computer simulation show the new hiding technique have better properties with high security, imperceptibility and capacity for hidden information in comparison with the conventional scheme such as LSB (Least Significance Bit).

  17. An Industrial Model Based Disturbance Feedback Control Scheme

    DEFF Research Database (Denmark)

    Kawai, Fukiko; Nakazawa, Chikashi; Vinther, Kasper

    2014-01-01

    This paper presents a model based disturbance feedback control scheme. Industrial process systems have been traditionally controlled by using relay and PID controller. However these controllers are affected by disturbances and model errors and these effects degrade control performance. The authors...... propose a new control method that can decrease the negative impact of disturbance and model errors. The control method is motivated by industrial practice by Fuji Electric. Simulation tests are examined with a conventional PID controller and the disturbance feedback control. The simulation results...

  18. Performance Evaluation of Page Migration Scheme for NVRAM-Based Wireless Sensor Nodes

    OpenAIRE

    Yeonseung Ryu

    2013-01-01

    A wireless sensor network consists of low-powered and multifunctional sensor nodes. Since each sensor node is operated by a battery, the energy management has become one of the critical design challenges in wireless sensor networks. Some recent studies have shown that DRAM-based main memory spends a significant portion of the total system power. In this paper, we studied a buffer management scheme for hybrid main memory that combines low-power nonvolatile RAM (NVRAM) and DRAM in order to redu...

  19. Cost-based droop scheme with lower generation costs for microgrids

    DEFF Research Database (Denmark)

    Nutkani, Inam Ullah; Loh, Poh Chiang; Blaabjerg, Frede

    2014-01-01

    In an autonomous microgrid where centralised management and communication links are not viable, droop control has been the preferred scheme for distributed generators (DGs). At present, although many droop variations have surfaced, they mainly focus on achieving proportional power sharing based...... on the DG kilovolts ampere (kVA) ratings. Other factors like generation costs, efficiencies and emission penalties at different load demands have not been considered. This omission might not be appropriate if different types of DGs are present in the microgrids. As an alternative, this study proposes a cost......-based droop scheme, whose objective is to reduce a generation cost function realised with various DG operating characteristics taken into consideration. Where desired, proportional power sharing based on the DG kVA ratings can also be included, whose disadvantage is a slightly higher generation cost, which...

  20. The cost-effectiveness of managed care regarding chronic medicine prescriptions in a selected medical scheme

    Directory of Open Access Journals (Sweden)

    K. Day

    1998-09-01

    Full Text Available The purpose of the study was to examine the cost-effectiveness of managed care interventions with respect to prescriptions for chronic illness sufferers enrolled with a specific medical scheme. The illnesses included, were epilepsy, hypertension, diabetes and asthma. The managed care interventions applied were a primary discount; the use of preferred provider pharmacies, and drug utilization review. It was concluded that the managed care interventions resulted in some real cost savings.

  1. EBAA: An efficient broadcast authentication scheme for ADS-B communication based on IBS-MR

    Directory of Open Access Journals (Sweden)

    Yang Haomiao

    2014-06-01

    Full Text Available Automatic dependent surveillance-broadcast (ADS-B systems can broadcast satellite-based aircraft position, identification, etc., periodically, and are now on track to replace radar to become the backbone of next-generation air traffic management (ATM systems. However, ADS-B systems suffer severe cyber-security problems due to the broadcast-type data link and the lack of designed-in security measures. Especially, since ADS-B messages are unauthenticated, it is easy to insert fake aircraft into a system via spoofing or insertion of false messages. Unfortunately, the authentication for ADS-B messages has not yet been well studied. In this paper, based on identity-based signature with message recovery (IBS-MR, an efficient broadcast authentication scheme for ADS-B messages is proposed. The security analysis demonstrates that the scheme can achieve authenticity and integrity of ADS-B broadcast messages, as well as adaptive evolution of broadcasters’ private keys. The performance evaluation shows that the scheme is computationally efficient for typical avionics devices with limited resources. Furthermore, the scheme achieves low communication overhead since broadcast messages can be recovered from signatures, and thus it is suitable for low-bandwidth ADS-B data link.

  2. Twig Pattern Matching Based on Compressed Path Labeling Scheme

    Institute of Scientific and Technical Information of China (English)

    NING Bo; WANG Guoren; DONG Ke

    2007-01-01

    Holistic twig query processing techniques based on region encoding have been developed to minimize the intermediate results, namely, those root-to-leaf path matches that are not in the final twig results. These algorithms have to scan all the streams of tags in query patterns. However, useless path matches cannot be completely avoided. TJFast which is based on the labeling scheme of Extended Dewey has been proposed to avoid useless intermediate results, and it only needs to access the labels of the leaf query nodes. However, it don't concern about the characteristics of elements with the same parent, and it has to merge join all the intermediate results which are evaluated during the first phrase. We propose a new labeling scheme to compress the XML elements which have the same characteristic. Based on the compressed path-labeled streams, a new novel holistic twig query algorithm named CPJoin is designed. Finally, implementation results are provided to show that CPJoin has good performance on both real and synthetic data.

  3. An Effective Queue Management Scheme for Data Communication

    Directory of Open Access Journals (Sweden)

    Sheela Thavasi

    2011-01-01

    Full Text Available Problem statement: The growth in the needs of Internet applications that transmit massive amount of data has led to the emergence of Effective Queue Management. Approach: Queues were used to smooth spikes in incoming packet rates and to allow the router sufficient time for packet processing. When the waiting time is less a better queue management is ensured thereby resulting in increased flow in the queue. When the incoming packet rate was higher than the router's outgoing packet rate, the queue size was increased, eventually exceeding the available buffer space. With respect to TCP’s RED queue management, the problem was that the buffer size was reduced to half and the packets were dropped abruptly. The congestion was detected early and the packets were dropped. The merit may be that congestion was detected early but the adverse effect was loss of packets. Results: The sender had to retransmit causing delay onto the network. This caused adverse effects on the network performance. In proposed system queue was extended whenever the number of packets present in the queue exceeds queue threshold. Packet drops were insignificantly even during network congestion. When the queue was continuously extended and if there was steady inflow of high volume of data, packet drop ratio was insignificant. Conclusions: Thus by the adoption of the proposed work, network throughput rose considerably thereby enabling effective data transfer. So it exhibits high bandwidth utilization, good throughput and processing time.

  4. Geometrically Invariant Watermarking Scheme Based on Local Feature Points

    Directory of Open Access Journals (Sweden)

    Jing Li

    2012-06-01

    Full Text Available Based on local invariant feature points and cross ratio principle, this paper presents a feature-point-based image watermarking scheme. It is robust to geometric attacks and some signal processes. It extracts local invariant feature points from the image using the improved scale invariant feature transform algorithm. Utilizing these points as vertexes it constructs some quadrilaterals to be as local feature regions. Watermark is inserted these local feature regions repeatedly. In order to get stable local regions it adjusts the number and distribution of extracted feature points. In every chosen local feature region it decides locations to embed watermark bits based on the cross ratio of four collinear points, the cross ratio is invariant to projective transformation. Watermark bits are embedded by quantization modulation, in which the quantization step value is computed with the given PSNR. Experimental results show that the proposed method can strongly fight more geometrical attacks and the compound attacks of geometrical ones.

  5. Modelling tools for managing Induced RiverBank Filtration MAR schemes

    Science.gov (United States)

    De Filippis, Giovanna; Barbagli, Alessio; Marchina, Chiara; Borsi, Iacopo; Mazzanti, Giorgio; Nardi, Marco; Vienken, Thomas; Bonari, Enrico; Rossetto, Rudy

    2017-04-01

    Induced RiverBank Filtration (IRBF) is a widely used technique in Managed Aquifer Recharge (MAR) schemes, when aquifers are hydraulically connected with surface water bodies, with proven positive effects on quality and quantity of groundwater. IRBF allows abstraction of a large volume of water, avoiding large decrease in groundwater heads. Moreover, thanks to the filtration process through the soil, the concentration of chemical species in surface water can be reduced, thus becoming an excellent resource for the production of drinking water. Within the FP7 MARSOL project (demonstrating Managed Aquifer Recharge as a SOLution to water scarcity and drought; http://www.marsol.eu/), the Sant'Alessio IRBF (Lucca, Italy) was used to demonstrate the feasibility and technical and economic benefits of managing IRBF schemes (Rossetto et al., 2015a). The Sant'Alessio IRBF along the Serchio river allows to abstract an overall amount of about 0.5 m3/s providing drinking water for 300000 people of the coastal Tuscany (mainly to the town of Lucca, Pisa and Livorno). The supplied water is made available by enhancing river bank infiltration into a high yield (10-2 m2/s transmissivity) sandy-gravelly aquifer by rising the river head and using ten vertical wells along the river embankment. A Decision Support System, consisting in connected measurements from an advanced monitoring network and modelling tools was set up to manage the IRBF. The modelling system is based on spatially distributed and physically based coupled ground-/surface-water flow and solute transport models integrated in the FREEWAT platform (developed within the H2020 FREEWAT project - FREE and Open Source Software Tools for WATer Resource Management; Rossetto et al., 2015b), an open source and public domain GIS-integrated modelling environment for the simulation of the hydrological cycle. The platform aims at improving water resource management by simplifying the application of EU water-related Directives and at

  6. Generating Unstable Resonances for Extraction Schemes Based on Transverse Splitting

    CERN Document Server

    Giovannozzi, M; Turchetti, G

    2009-01-01

    A few years ago, a novel multi-turn extraction scheme was proposed, based on particle trapping inside stable resonances. Numerical simulations and experimental tests have confirmed the feasibility of such a scheme for low order resonances. While the third-order resonance is generically unstable and those higher than fourth-order are generically stable, the fourth-order resonance can be either stable or unstable depending on the specifics of the system under consideration. By means of the Normal Form a general approach to control the stability of the fourth-order resonance has been derived. This approach is based on the control of the amplitude detuning and the general form for a lattice with an arbitrary number of sextupole and octupole families is derived in this paper. Numerical simulations have confirmed the analytical results and have shown that, when crossing the unstable fourth-order resonance, the region around the centre of the phase space is depleted and particles are trapped in only the four stable ...

  7. Motion feature extraction scheme for content-based video retrieval

    Science.gov (United States)

    Wu, Chuan; He, Yuwen; Zhao, Li; Zhong, Yuzhuo

    2001-12-01

    This paper proposes the extraction scheme of global motion and object trajectory in a video shot for content-based video retrieval. Motion is the key feature representing temporal information of videos. And it is more objective and consistent compared to other features such as color, texture, etc. Efficient motion feature extraction is an important step for content-based video retrieval. Some approaches have been taken to extract camera motion and motion activity in video sequences. When dealing with the problem of object tracking, algorithms are always proposed on the basis of known object region in the frames. In this paper, a whole picture of the motion information in the video shot has been achieved through analyzing motion of background and foreground respectively and automatically. 6-parameter affine model is utilized as the motion model of background motion, and a fast and robust global motion estimation algorithm is developed to estimate the parameters of the motion model. The object region is obtained by means of global motion compensation between two consecutive frames. Then the center of object region is calculated and tracked to get the object motion trajectory in the video sequence. Global motion and object trajectory are described with MPEG-7 parametric motion and motion trajectory descriptors and valid similar measures are defined for the two descriptors. Experimental results indicate that our proposed scheme is reliable and efficient.

  8. Disseminated Public-Key Management and Certificate Generation Scheme for MANET

    Directory of Open Access Journals (Sweden)

    Sanjay Kumar Chowlam

    2011-07-01

    Full Text Available In this paper, we first discuss the predominant assail abilities in the mobile ad hoc networks, which have made it much easier to prone to attacks than the traditional wired network. Then we discuss the basic operations of our public-key management scheme: creation of public (and private keys, issuing public-key certificates, storage of certificates, and key authentication by the nodes themselves without the control of any principal authority. More over the public key management scheme serves as an underlying mechanism for both key distribution and establishing security relationships between nodes.

  9. ID-based authentication scheme combined with identity-based encryption with fingerprint hashing

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Current identity-based (ID) cryptosystem lacks the mechanisms of two-party authentication and user's private key distribution. Some ID-based signcryption schemes and ID-based authenticated key agreement protocols have been presented, but they cannot solve the problem completely. A novel ID-based authentication scheme based on ID-based encryption (IBE) and fingerprint hashing method is proposed to solve the difficulties in the IBE scheme, which includes message receiver authenticating the sender, the trusted authority (TA) authenticating the users and transmitting the private key to them. Furthermore, the scheme extends the application of fingerprint authentication from terminal to network and protects against fingerprint data fabrication. The fingerprint authentication method consists of two factors. This method combines a token key, for example, the USB key, with the user's fingerprint hash by mixing a pseudo-random number with the fingerprint feature. The security and experimental efficiency meet the requirements of practical applications.

  10. A Lattice-Based Identity-Based Proxy Blind Signature Scheme in the Standard Model

    Directory of Open Access Journals (Sweden)

    Lili Zhang

    2014-01-01

    Full Text Available A proxy blind signature scheme is a special form of blind signature which allowed a designated person called proxy signer to sign on behalf of original signers without knowing the content of the message. It combines the advantages of proxy signature and blind signature. Up to date, most proxy blind signature schemes rely on hard number theory problems, discrete logarithm, and bilinear pairings. Unfortunately, the above underlying number theory problems will be solvable in the postquantum era. Lattice-based cryptography is enjoying great interest these days, due to implementation simplicity and provable security reductions. Moreover, lattice-based cryptography is believed to be hard even for quantum computers. In this paper, we present a new identity-based proxy blind signature scheme from lattices without random oracles. The new scheme is proven to be strongly unforgeable under the standard hardness assumption of the short integer solution problem (SIS and the inhomogeneous small integer solution problem (ISIS. Furthermore, the secret key size and the signature length of our scheme are invariant and much shorter than those of the previous lattice-based proxy blind signature schemes. To the best of our knowledge, our construction is the first short lattice-based identity-based proxy blind signature scheme in the standard model.

  11. DRO: domain-based route optimization scheme for nested mobile networks

    Directory of Open Access Journals (Sweden)

    Chuang Ming-Chin

    2011-01-01

    Full Text Available Abstract The network mobility (NEMO basic support protocol is designed to support NEMO management, and to ensure communication continuity between nodes in mobile networks. However, in nested mobile networks, NEMO suffers from the pinball routing problem, which results in long packet transmission delays. To solve the problem, we propose a domain-based route optimization (DRO scheme that incorporates a domain-based network architecture and ad hoc routing protocols for route optimization. DRO also improves the intra-domain handoff performance, reduces the convergence time during route optimization, and avoids the out-of-sequence packet problem. A detailed performance analysis and simulations were conducted to evaluate the scheme. The results demonstrate that DRO outperforms existing mechanisms in terms of packet transmission delay (i.e., better route-optimization, intra-domain handoff latency, convergence time, and packet tunneling overhead.

  12. 基于电力需求响应的智能家电管理控制方案%Management and Control Scheme for Intelligent Home Appliances Based on Electricity Demand Response

    Institute of Scientific and Technical Information of China (English)

    汤奕; 鲁针针; 宁佳; 林扬宇

    2014-01-01

    It”s worth in-depth research effectively integrating the potential of the user side response to the power grid using smart electricity demand response(DR)technology to improve its secure,stable and economical operation.Take the residential users for example,by using the capabilities of bi-directional interactive operation of the smart grid,a smart home appliances management(HAM)system with its control scheme is proposed.Models of different appliances are developed and according to their operating characteristics,an evaluation index is proposed that can represent the comfort of different appliances.To meet the requirements of DR and on the premise of the users”comfort,dynamic priorities of different appliances are calculated online according to their real-time status,and load control decision is performed in order of priority.The role in improving the power grid load curve is analyzed after the participation of all appliances in DR.The effects of the proposed HAM and its control scheme are analyzed for both the power company and the user.Simulation results have verified the rationality of the home appliance management scheme proposed.%运用智能电力需求响应(DR)技术,有效整合用户侧电网响应潜力以提升电网运行的安全性、稳定性和经济性值得深入研究。以居民用户为例,利用智能电网双向交互能力,提出了智能家电管理(H AM)系统及其控制方案。建立了不同家电的控制模型,并根据家电运行特点提出了家电舒适度指数的概念。在满足DR用电要求并尽量满足用户舒适度的前提下,根据家电实时状态在线计算其动态优先级,并按照优先级顺序执行负荷控制决策。分析了不同家电参与DR 后,对改善电网负荷曲线的作用。从电力公司与用户两方面分析了所提控制方案的控制效果。仿真结果验证了智能家电控制方案的合理性。

  13. Comparison of medicines management strategies in insurance schemes in middle-income countries: four case studies.

    Science.gov (United States)

    Kaplan, Warren A; Ashigbie, Paul G; Brooks, Mohamad I; Wirtz, Veronika J

    2017-01-01

    Many middle-income countries are scaling up health insurance schemes to provide financial protection and access to affordable medicines to poor and uninsured populations. Although there is a wealth of evidence on how high income countries with mature insurance schemes manage cost-effective use of medicines, there is limited evidence on the strategies used in middle-income countries. This paper compares the medicines management strategies that four insurance schemes in middle-income countries use to improve access and cost-effective use of medicines among beneficiaries. We compare key strategies promoting cost-effective medicines use in the New Rural Cooperative Medical Scheme (NCMS) in China, National Health Insurance Scheme in Ghana, Jamkesmas in Indonesia and Seguro Popular in Mexico. Through the peer-reviewed and grey literature as of late 2013, we identified strategies that met our inclusion criteria as well as any evidence showing if, and/or how, these strategies affected medicines management. Stakeholders involved and affected by medicines coverage policies in these insurance schemes were asked to provide relevant documents describing the medicines related aspects of these insurance programs. We also asked them specifically to identify publications discussing the unintended consequences of the strategies implemented. Use of formularies, bulk procurement, standard treatment guidelines and separation of prescribing and dispensing were present in all four schemes. Also, increased transparency through publication of tender agreements and procurement prices was introduced in all four. Common strategies shared by three out of four schemes were medicine price negotiation or rebates, generic reference pricing, fixed salaries for prescribers, accredited preferred provider network, disease management programs, and monitoring of medicines purchases. Cost-sharing and payment for performance was rarely used. There was a lack of performance monitoring strategies in all

  14. Adaptive SPC monitoring scheme for DOE-based APC

    Institute of Scientific and Technical Information of China (English)

    Ye Liang; Pan Ershun; Xi Lifeng

    2008-01-01

    Automatic process control (APC) based on design of experiment (DOE) is a cost-efficient approach for variation reduction. The process changes both in mean and variance owing to online parameter adjustment make it hard to apply traditional SPC charts in such DOE-based APC applied process. An adaptive SPC scheme is developed, which can better track the process transitions and achieve the possible SPC run cost reduction when the process is stable. The control law of SPC parameters is designed by fully utilizing the estimation properties of the process model instead of traditionally using the data collected from the production line. An example is provided to illustrate the proposed adaptive SPC design approach.

  15. A group signature scheme based on quantum teleportation

    Energy Technology Data Exchange (ETDEWEB)

    Wen Xiaojun; Tian Yuan; Ji Liping; Niu Xiamu, E-mail: wxjun36@gmail.co [Information Countermeasure Technique Research Institute, Harbin Institute of Technology, Harbin 150001 (China)

    2010-05-01

    In this paper, we present a group signature scheme using quantum teleportation. Different from classical group signature and current quantum signature schemes, which could only deliver either group signature or unconditional security, our scheme guarantees both by adopting quantum key preparation, quantum encryption algorithm and quantum teleportation. Security analysis proved that our scheme has the characteristics of group signature, non-counterfeit, non-disavowal, blindness and traceability. Our quantum group signature scheme has a foreseeable application in the e-payment system, e-government, e-business, etc.

  16. Cluster-based Multihop Synchronization Scheme for Femtocell Network

    Directory of Open Access Journals (Sweden)

    Aisha H. Abdalla

    2012-10-01

    Full Text Available ABSTRACT: Femtocell technology has been drawing considerable attention as a cost-effective means of improving cellular coverage and capacity. It is connected to the core network through an IP backhaul and can only use timing protocols such as IEEE1588 or Network Time Protocol (NTP. Furthermore, the femtocell is installed indoor, and cannot use a GPS antenna for time synchronization.  High-precision crystal oscillators can solve the timing problem, but they are often too expensive for consumer grade devices. Therefore, femtocell Base Station (fBS synchronization is one of the principle technical trends in femtocell deployment. Since fBSand macrocell Base Station (mBS network operates on the same frequency under a licensed spectrum, fBS network can interfere with the macrocell network. In addition, fBSs can also interfere with each other if multiple units are in close proximity. Furthermore, in a flat fBS structured network using IEEE 1588 synchronization algorithm and fBS-fBS synchronization scheme creates offset and frequency error which results inaccurate synchronization. In order to reduce offset and frequency error (skew, this paper proposed a cluster-based multihop synchronization scheme to achieve precise in fBS neighbor nodes. The proposed scheme is able to reduce the offset and skew significantly.ABSTRAK: Teknologi Femtocell telah menjadi tumpuan sebagai alat yang kos-efektif dalam memperbaiki liputan mudahalih dan kapasiti. Ia menghubungkan jaringan teras melalui IP backhaul dan hanya boleh menggunakan protokol masa seperti IEEE1588 atau Protokol Jaringan Masa (NTP. Seterusnya, femtocell dipasang di dalam, dan tidak boleh menggunakan antena GPS untuk sinkronisasi masa. Osilator Kristal yang tinggi kejituannya boleh menyelesaikan masalah masa, tetapi ianya mahal bagi gred peranti consumer. Oleh itu, sinkronisasi Stesen Asas femtocell (fBS adalah salah satu tren teknikal prinsip dalam deployment femtocell. Memandangkan fBS dan jaringan

  17. Energy Aware Cluster Based Routing Scheme For Wireless Sensor Network

    Directory of Open Access Journals (Sweden)

    Roy Sohini

    2015-09-01

    Full Text Available Wireless Sensor Network (WSN has emerged as an important supplement to the modern wireless communication systems due to its wide range of applications. The recent researches are facing the various challenges of the sensor network more gracefully. However, energy efficiency has still remained a matter of concern for the researches. Meeting the countless security needs, timely data delivery and taking a quick action, efficient route selection and multi-path routing etc. can only be achieved at the cost of energy. Hierarchical routing is more useful in this regard. The proposed algorithm Energy Aware Cluster Based Routing Scheme (EACBRS aims at conserving energy with the help of hierarchical routing by calculating the optimum number of cluster heads for the network, selecting energy-efficient route to the sink and by offering congestion control. Simulation results prove that EACBRS performs better than existing hierarchical routing algorithms like Distributed Energy-Efficient Clustering (DEEC algorithm for heterogeneous wireless sensor networks and Energy Efficient Heterogeneous Clustered scheme for Wireless Sensor Network (EEHC.

  18. Saturation Detection-Based Blocking Scheme for Transformer Differential Protection

    Directory of Open Access Journals (Sweden)

    Byung Eun Lee

    2014-07-01

    Full Text Available This paper describes a current differential relay for transformer protection that operates in conjunction with a core saturation detection-based blocking algorithm. The differential current for the magnetic inrush or over-excitation has a point of inflection at the start and end of each saturation period of the transformer core. At these instants, discontinuities arise in the first-difference function of the differential current. The second- and third-difference functions convert the points of inflection into pulses, the magnitudes of which are large enough to detect core saturation. The blocking signal is activated if the third-difference of the differential current is larger than the threshold and is maintained for one cycle. In addition, a method to discriminate between transformer saturation and current transformer (CT saturation is included. The performance of the proposed blocking scheme was compared with that of a conventional harmonic blocking method. The test results indicate that the proposed scheme successfully discriminates internal faults even with CT saturation from the magnetic inrush, over-excitation, and external faults with CT saturation, and can significantly reduce the operating time delay of the relay.

  19. An adaptive short-term prediction scheme for wind energy storage management

    Energy Technology Data Exchange (ETDEWEB)

    Blonbou, Ruddy, E-mail: ruddy.blonbou@univ-ag.f [Geosciences and Energy Research Laboratory, Universite des Antilles et de la Guyane, Guadeloupe (France); Monjoly, Stephanie; Dorville, Jean-Francois [Geosciences and Energy Research Laboratory, Universite des Antilles et de la Guyane, Guadeloupe (France)

    2011-06-15

    Research highlights: {yields} We develop a real time algorithm for grid-connected wind energy storage management. {yields} The method aims to guarantee, with {+-}5% error margin, the power sent to the grid. {yields} Dynamic scheduling of energy storage is based on short-term energy prediction. {yields} Accurate predictions reduce the need in storage capacity. -- Abstract: Efficient forecasting scheme that includes some information on the likelihood of the forecast and based on a better knowledge of the wind variations characteristics along with their influence on power output variation is of key importance for the optimal integration of wind energy in island's power system. In the Guadeloupean archipelago (French West-Indies), with a total wind power capacity of 25 MW; wind energy can represent up to 5% of the instantaneous electricity production. At this level, wind energy contribution can be equivalent to the current network primary control reserve, which causes balancing difficult. The share of wind energy is due to grow even further since the objective is set to reach 118 MW by 2020. It is an absolute evidence for the network operator that due to security concerns of the electrical grid, the share of wind generation should not increase unless solutions are found to solve the prediction problem. The University of French West-Indies and Guyana has developed a short-term wind energy prediction scheme that uses artificial neural networks and adaptive learning procedures based on Bayesian approach and Gaussian approximation. This paper reports the results of the evaluation of the proposed approach; the improvement with respect to the simple persistent prediction model was globally good. A discussion on how such a tool combined with energy storage capacity could help to smooth the wind power variation and improve the wind energy penetration rate into island utility network is also proposed.

  20. Lessons from community-based payment for ecosystem service schemes: from forests to rangelands.

    Science.gov (United States)

    Dougill, Andrew J; Stringer, Lindsay C; Leventon, Julia; Riddell, Mike; Rueff, Henri; Spracklen, Dominick V; Butt, Edward

    2012-11-19

    Climate finance investments and international policy are driving new community-based projects incorporating payments for ecosystem services (PES) to simultaneously store carbon and generate livelihood benefits. Most community-based PES (CB-PES) research focuses on forest areas. Rangelands, which store globally significant quantities of carbon and support many of the world's poor, have seen little CB-PES research attention, despite benefitting from several decades of community-based natural resource management (CBNRM) projects. Lessons from CBNRM suggest institutional considerations are vital in underpinning the design and implementation of successful community projects. This study uses documentary analysis to explore the institutional characteristics of three African community-based forest projects that seek to deliver carbon-storage and poverty-reduction benefits. Strong existing local institutions, clear land tenure, community control over land management decision-making and up-front, flexible payment schemes are found to be vital. Additionally, we undertake a global review of rangeland CBNRM literature and identify that alongside the lessons learned from forest projects, rangeland CB-PES project design requires specific consideration of project boundaries, benefit distribution, capacity building for community monitoring of carbon storage together with awareness-raising using decision-support tools to display the benefits of carbon-friendly land management. We highlight that institutional analyses must be undertaken alongside improved scientific studies of the carbon cycle to enable links to payment schemes, and for them to contribute to poverty alleviation in rangelands.

  1. Cryptanalysis and Improvement of a Biometric-Based Multi-Server Authentication and Key Agreement Scheme.

    Directory of Open Access Journals (Sweden)

    Chengqi Wang

    Full Text Available With the security requirements of networks, biometrics authenticated schemes which are applied in the multi-server environment come to be more crucial and widely deployed. In this paper, we propose a novel biometric-based multi-server authentication and key agreement scheme which is based on the cryptanalysis of Mishra et al.'s scheme. The informal and formal security analysis of our scheme are given, which demonstrate that our scheme satisfies the desirable security requirements. The presented scheme provides a variety of significant functionalities, in which some features are not considered in the most of existing authentication schemes, such as, user revocation or re-registration and biometric information protection. Compared with several related schemes, our scheme has more secure properties and lower computation cost. It is obviously more appropriate for practical applications in the remote distributed networks.

  2. A secure smart-card based authentication and key agreement scheme for telecare medicine information systems.

    Science.gov (United States)

    Lee, Tian-Fu; Liu, Chuan-Ming

    2013-06-01

    A smart-card based authentication scheme for telecare medicine information systems enables patients, doctors, nurses, health visitors and the medicine information systems to establish a secure communication platform through public networks. Zhu recently presented an improved authentication scheme in order to solve the weakness of the authentication scheme of Wei et al., where the off-line password guessing attacks cannot be resisted. This investigation indicates that the improved scheme of Zhu has some faults such that the authentication scheme cannot execute correctly and is vulnerable to the attack of parallel sessions. Additionally, an enhanced authentication scheme based on the scheme of Zhu is proposed. The enhanced scheme not only avoids the weakness in the original scheme, but also provides users' anonymity and authenticated key agreements for secure data communications.

  3. Recovery schemes for different distributed connection management in generalized multi-protocol label switching networks

    Institute of Scientific and Technical Information of China (English)

    Can Wang; Yuefeng Ji

    2007-01-01

    As the wavelength division multiplexing (WDM) technology matures and the demands for bandwidth increase, survivability becomes more and more important in generalized multi-protocol label switching (GMPLS) controlled intelligent optical networks (IONs). There are great interests to study the performance of restorability under one certain connection management strategy. And studies in the problem of providing recovery from link failures under two different resource reservation schemes, forward reservation protocols (FRPs) and backward reservation protocols (BRPs), are presented. They are examined from the point of view of connection blocking probability, restorability and average recovery time. The two different connection management schemes and the survey of different recovery schemes are first presented. The performance of these recovery strategies is analyzed and compared both through theoretical analysis and simulation results. The main stressed idea is that using BRPs gives the best performance in terms of restorability and blocking probability in restorable GMPLS networks.

  4. Identity based Encryption and Biometric Authentication Scheme for Secure Data Access in Cloud Computing

    DEFF Research Database (Denmark)

    Cheng, Hongbing; Rong, Chunming; Tan, Zheng-Hua

    2012-01-01

    access scheme based on identity-based encryption and biometric authentication for cloud computing. Firstly, we describe the security concern of cloud computing and then propose an integrated data access scheme for cloud computing, the procedure of the proposed scheme include parameter setup, key...

  5. Topic Maps Based Project Knowledge Management

    Institute of Scientific and Technical Information of China (English)

    Wu Xiaofan; Zhou Liang; Zhang Lei; Li Lingzhi; Ding Qiulin

    2006-01-01

    Based on topic maps, a preprocessing scheme using similarity comparision is presented and applied in knowledge management.Topic and occurrence-oriented merging algorithm is also introduced to implement knowledge integration for the sub-system. An Omnigator-supported example from an aeroaustic institute is utilised to validate the preprocessing method and the result indicates it can speed up the research schedule.

  6. Hydrogeological modelling of the Atlantis aquifer for management support to the Atlantis water supply scheme

    CSIR Research Space (South Africa)

    Jovanovic, Nebo

    2017-01-01

    Full Text Available The Atlantis Water Supply Scheme (AWSS, Western Cape, South Africa) has been in operation for about 40 years as a means to supply and augment drinking water to the town of Atlantis via managed aquifer recharge (MAR). In this study, the numerical...

  7. Switched-based interference reduction scheme for open-access overlaid cellular networks

    KAUST Repository

    Radaydeh, Redha Mahmoud Mesleh

    2012-06-01

    Femtocells have been proposed to enhance the spatial coverage and system capacity of existing cellular networks. However, this technology may result in significant performance loss due to the increase in co-channel interference, particularly when coordination between access points is infeasible. This paper targets interference management in such overlaid networks. It is assumed that the femtocells employ the open-access strategy to reduce cross-tier interference, and can share resources concurrently. It is also assumed that each end user (EU) can access one channel at a time, and transfer limited feedback. To reduce the effect of co-tier interference in the absence of the desired EU channel state information (CSI) at the serving access point as well as coordination between active access points, a switched scheme based on the interference levels associated with available channels is proposed. Through the analysis, the scheme modes of operation in under-loaded and over-loaded channels are studied, from which the statistics of the resulting interference power are quantified. The impact of the proposed scheme on the received desired power is thoroughly discussed. In addition, the effect of the switching threshold on the achieved performance of the desired EU is investigated. The results clarify that the proposed scheme can improve the performance while reducing the number of examined channels and feedback load. © 2012 IEEE.

  8. A LAGUERRE VORONOI BASED SCHEME FOR MESHING PARTICLE SYSTEMS.

    Science.gov (United States)

    Bajaj, Chandrajit

    2005-06-01

    We present Laguerre Voronoi based subdivision algorithms for the quadrilateral and hexahedral meshing of particle systems within a bounded region in two and three dimensions, respectively. Particles are smooth functions over circular or spherical domains. The algorithm first breaks the bounded region containing the particles into Voronoi cells that are then subsequently decomposed into an initial quadrilateral or an initial hexahedral scaffold conforming to individual particles. The scaffolds are subsequently refined via applications of recursive subdivision (splitting and averaging rules). Our choice of averaging rules yield a particle conforming quadrilateral/hexahedral mesh, of good quality, along with being smooth and differentiable in the limit. Extensions of the basic scheme to dynamic re-meshing in the case of addition, deletion, and moving particles are also discussed. Motivating applications of the use of these static and dynamic meshes for particle systems include the mechanics of epoxy/glass composite materials, bio-molecular force field calculations, and gas hydrodynamics simulations in cosmology.

  9. Watermarking scheme of colour image based on chaotic sequences

    Institute of Scientific and Technical Information of China (English)

    LIU Nian-sheng; GUO Dong-hui

    2009-01-01

    The proposed perceptual mask is based on the singularity of cover image and matches very well with the properties of the human visual system. The cover colour image is decomposed into several subbands by the wavelet transform. The water-mark composed of chaotic sequence and the covert image is embedded into the subband with the largest energy. The chaos system plays an important role in the security invisibility and robustness of the proposed scheme. The parameter and initial state of chaos system can directly influence the generation of watermark information as a key. Moreover, the watermark information has the property of spread spectrum signal by chaotic sequence to improve the invisibility and security of watermarked image. Experimental results and comparisons with other watermarking techniques prove that the proposed algorithm is effective and feasible, and improves the security, invisibility and robustness of watermarking information.

  10. Script format document authentication scheme based on watermarking techniques

    Directory of Open Access Journals (Sweden)

    M. González-Lee

    2015-06-01

    Full Text Available In almost all watermarking-based document authentication systems, the documents are considered as binary images and then, the watermark is embedded using some image watermarking algorithm. However actually important documents are saved using document file formats, such as Portable Document Format (PDF or Open Document Format (ODF, among others, because in general the file size is smaller compared with an image file, and also these are considered as more secure than other types of file format. However, the documents with these formats can also be maliciously modified for illegal purposes, making necessary the development of mechanisms that are able to detect such modifications. Considering the situations mentioned above, this paper proposes a document authentication scheme in which a watermark is directly embedded into the document file format as part of the document itself. The experimental results show a desirable performance of the proposed algorithm.

  11. Hierarchical Spread Spectrum Fingerprinting Scheme Based on the CDMA Technique

    Directory of Open Access Journals (Sweden)

    Kuribayashi Minoru

    2011-01-01

    Full Text Available Abstract Digital fingerprinting is a method to insert user's own ID into digital contents in order to identify illegal users who distribute unauthorized copies. One of the serious problems in a fingerprinting system is the collusion attack such that several users combine their copies of the same content to modify/delete the embedded fingerprints. In this paper, we propose a collusion-resistant fingerprinting scheme based on the CDMA technique. Our fingerprint sequences are orthogonal sequences of DCT basic vectors modulated by PN sequence. In order to increase the number of users, a hierarchical structure is produced by assigning a pair of the fingerprint sequences to a user. Under the assumption that the frequency components of detected sequences modulated by PN sequence follow Gaussian distribution, the design of thresholds and the weighting of parameters are studied to improve the performance. The robustness against collusion attack and the computational costs required for the detection are estimated in our simulation.

  12. Holographic storage scheme based on digital signal processing

    Institute of Scientific and Technical Information of China (English)

    Kebin Jia(贾克斌); Dapeng Yang(杨大鹏); Shubo Dun(敦书波); Shiquan Tao(陶世荃); Mingyan Qin(覃鸣燕)

    2003-01-01

    In this paper, a holographic storage scheme for multimedia data storage and retrieval based on the digitalsignal processing (DSP) is designed. A communication model for holographic storage system is obtainedon the analogy of traditional communication system. Many characteristics of holographic storage areembodied in the communication model. Then some new methods of DSP including two-dimensional (2-D)shifting interleaving, encoding and decoding of modulation-array (MA) code and method of soft-decision,etc. are proposed and employed in the system. From the results of experiments it can be seen that thosemeasures can effectively reduce the influence of noise. A segment of multimedia data, including video andaudio data, is retrieved successfully after holographic storage by using those techniques.

  13. The costs and benefits of a migratory species under different management schemes.

    Science.gov (United States)

    Skonhoft, Anders

    2005-07-01

    This paper analyses how different management schemes influence the exploitation and economics of a wildlife population--the moose (Alces alces)--that is both a value (harvesting income) and a pest (forestry damage). Two regimes are explored; the unified management scheme where the wildlife manager aims to find harvesting quotas that maximise the overall benefit of the moose population, and the market solution where the landowners follow their narrow self-interests and maximise their private profit. Because the moose is partly a migratory species, these regimes will differ both with respect to harvesting income and browsing damage, and the landowners will experience different profit. The unified scheme is very similar to the actual Scandinavian management, while the market solution is closer to the management policy one finds in North America. In the first part of the paper it is shown how the harvesting quotas and browsing damage under these two regimes are influenced by dispersal as well as other ecological and economic factors. In the last part of the paper it is demonstrated that under the unified management regime the present practice of neglecting migration may lead to sub-optimally sized populations of migrating moose and an overall economic loss. It is also shown that neglecting migration leads to a substantial profit transfer among the landowners. The model is supported by a real life numerical example.

  14. An Improvement of Robust Biometrics-Based Authentication and Key Agreement Scheme for Multi-Server Environments Using Smart Cards.

    Science.gov (United States)

    Moon, Jongho; Choi, Younsung; Jung, Jaewook; Won, Dongho

    2015-01-01

    In multi-server environments, user authentication is a very important issue because it provides the authorization that enables users to access their data and services; furthermore, remote user authentication schemes for multi-server environments have solved the problem that has arisen from user's management of different identities and passwords. For this reason, numerous user authentication schemes that are designed for multi-server environments have been proposed over recent years. In 2015, Lu et al. improved upon Mishra et al.'s scheme, claiming that their remote user authentication scheme is more secure and practical; however, we found that Lu et al.'s scheme is still insecure and incorrect. In this paper, we demonstrate that Lu et al.'s scheme is vulnerable to outsider attack and user impersonation attack, and we propose a new biometrics-based scheme for authentication and key agreement that can be used in multi-server environments; then, we show that our proposed scheme is more secure and supports the required security properties.

  15. A robust anonymous biometric-based remote user authentication scheme using smart cards

    Directory of Open Access Journals (Sweden)

    Ashok Kumar Das

    2015-04-01

    Full Text Available Several biometric-based remote user authentication schemes using smart cards have been proposed in the literature in order to improve the security weaknesses in user authentication system. In 2012, An proposed an enhanced biometric-based remote user authentication scheme using smart cards. It was claimed that the proposed scheme is secure against the user impersonation attack, the server masquerading attack, the password guessing attack, and the insider attack and provides mutual authentication between the user and the server. In this paper, we first analyze the security of An’s scheme and we show that this scheme has three serious security flaws in the design of the scheme: (i flaw in user’s biometric verification during the login phase, (ii flaw in user’s password verification during the login and authentication phases, and (iii flaw in user’s password change locally at any time by the user. Due to these security flaws, An’s scheme cannot support mutual authentication between the user and the server. Further, we show that An’s scheme cannot prevent insider attack. In order to remedy the security weaknesses found in An’s scheme, we propose a new robust and secure anonymous biometric-based remote user authentication scheme using smart cards. Through the informal and formal security analysis, we show that our scheme is secure against all possible known attacks including the attacks found in An’s scheme. The simulation results of our scheme using the widely-accepted AVISPA (Automated Validation of Internet Security Protocols and Applications tool ensure that our scheme is secure against passive and active attacks. In addition, our scheme is also comparable in terms of the communication and computational overheads with An’s scheme and other related existing schemes. As a result, our scheme is more appropriate for practical applications compared to other approaches.

  16. Cryptanalysis And Further Improvement Of A Biometric-Based Remote User Authentication Scheme Using Smart Cards

    CERN Document Server

    Das, Ashok Kumar

    2011-01-01

    Recently, Li et al. proposed a secure biometric-based remote user authentication scheme using smart cards to withstand the security flaws of Li-Hwang's efficient biometric-based remote user authentication scheme using smart cards. Li et al.'s scheme is based on biometrics verification, smart card and one-way hash function, and it also uses the random nonce rather than a synchronized clock, and thus it is efficient in computational cost and more secure than Li-Hwang's scheme. Unfortunately, in this paper we show that Li et al.'s scheme still has some security weaknesses in their design. In order to withstand those weaknesses in their scheme, we further propose an improvement of their scheme so that the improved scheme always provides proper authentication and as a result, it establishes a session key between the user and the server at the end of successful user authentication.

  17. HUFFMAN-BASED GROUP KEY ESTABLISHMENT SCHEME WITH LOCATION-AWARE

    Institute of Scientific and Technical Information of China (English)

    Gu Xiaozhuo; Yang Jianzu; Lan Julong

    2009-01-01

    Time efficiency of key establishment and update is one of the major problems contributory key managements strive to address. To achieve better time efficiency in key establishment, we propose a Location-based Huffman (L-Huffman) scheme. First, users are separated into several small groups to minimize communication cost when they are distributed over large networks. Second, both user's computation difference and message transmission delay are taken into consideration when Huffman coding is employed to forming the optimal key tree. Third, the combined weights in Huffman tree are located in a higher place of the key tree to reduce the variance of the average key generation time and minimize the longest key generation time. Simulations demonstrate that L-Huffman has much better performance in wide area networks and is a little better in local area network than Huffman scheme.

  18. A secure data outsourcing scheme based on Asmuth-Bloom secret sharing

    Science.gov (United States)

    Idris Muhammad, Yusuf; Kaiiali, Mustafa; Habbal, Adib; Wazan, A. S.; Sani Ilyasu, Auwal

    2016-11-01

    Data outsourcing is an emerging paradigm for data management in which a database is provided as a service by third-party service providers. One of the major benefits of offering database as a service is to provide organisations, which are unable to purchase expensive hardware and software to host their databases, with efficient data storage accessible online at a cheap rate. Despite that, several issues of data confidentiality, integrity, availability and efficient indexing of users' queries at the server side have to be addressed in the data outsourcing paradigm. Service providers have to guarantee that their clients' data are secured against internal (insider) and external attacks. This paper briefly analyses the existing indexing schemes in data outsourcing and highlights their advantages and disadvantages. Then, this paper proposes a secure data outsourcing scheme based on Asmuth-Bloom secret sharing which tries to address the issues in data outsourcing such as data confidentiality, availability and order preservation for efficient indexing.

  19. Enhanced ID-Based Authentication Scheme Using OTP in Smart Grid AMI Environment

    Directory of Open Access Journals (Sweden)

    Sang-Soo Yeo

    2014-01-01

    Full Text Available This paper presents the vulnerabilities analyses of KL scheme which is an ID-based authentication scheme for AMI network attached SCADA in smart grid and proposes a security-enhanced authentication scheme which satisfies forward secrecy as well as security requirements introduced in KL scheme and also other existing schemes. The proposed scheme uses MDMS which is the supervising system located in an electrical company as a time-synchronizing server in order to synchronize smart devices at home and conducts authentication between smart meter and smart devices using a new secret value generated by an OTP generator every session. The proposed scheme has forward secrecy, so it increases overall security, but its communication and computation overhead reduce its performance slightly, comparing the existing schemes. Nonetheless, hardware specification and communication bandwidth of smart devices will have better conditions continuously, so the proposed scheme would be a good choice for secure AMI environment.

  20. Cryptanalysis of an Elliptic Curve-based Signcryption Scheme

    CERN Document Server

    Toorani, Mohsen

    2010-01-01

    The signcryption is a relatively new cryptographic technique that is supposed to fulfill the functionalities of encryption and digital signature in a single logical step. Although several signcryption schemes are proposed over the years, some of them are proved to have security problems. In this paper, the security of Han et al.'s signcryption scheme is analyzed, and it is proved that it has many security flaws and shortcomings. Several devastating attacks are also introduced to the mentioned scheme whereby it fails all the desired and essential security attributes of a signcryption scheme.

  1. A New Privacy-preserving Path Authentication Scheme using RFID for Supply Chain Management

    Directory of Open Access Journals (Sweden)

    LEE, Y.

    2013-02-01

    Full Text Available This paper presents a privacy-preserving path-authentication method for supply chain management using RFID. Compared with previous works, our scheme employs only symmetric encryption and message authentication codes. This reduces computation and communication overhead. The proposed method also supports high-level privacy without the need for tamper-proof tags as compared with the previous methods. Performance analysis demonstrates that the proposed scheme requires far less computation resource than recent works, proving that less than 1 minute is enough to verify 100000 RFIDs in a conventional reader environment.

  2. New Cryptanalysis of an ID-based Password Authentication Scheme using Smart Cards and Fingerprints

    Directory of Open Access Journals (Sweden)

    MING-JHENG LI

    2010-11-01

    Full Text Available In 2002, Lee, Ryu and Yoo proposed a fingerprint-based remote user authentication scheme using a smart card. Their scheme would strengthen system security by verifying the smart card owner’s fingerprint. In 2003, Kim, Lee and Yoo proposed two ID-based password authentication schemes without passwords or verification tables,with smart card and fingerprints. The proposed nonce-based and timestamp-based schemes can withstand message replay attacks. In addition, the schemes can withstand impersonation attack. In this paper, we will first review Kim et al.’s ID-based password authentication schemes. Next, we will show that Kim et al.’s scheme still has the disadvantage of being vulnerable to impersonation attack.

  3. A novel chaotic encryption scheme based on arithmetic coding

    Energy Technology Data Exchange (ETDEWEB)

    Mi Bo [Department of Computer Science and Engineering, Chongqing University, Chongqing 400044 (China)], E-mail: mi_bo@163.com; Liao Xiaofeng; Chen Yong [Department of Computer Science and Engineering, Chongqing University, Chongqing 400044 (China)

    2008-12-15

    In this paper, under the combination of arithmetic coding and logistic map, a novel chaotic encryption scheme is presented. The plaintexts are encrypted and compressed by using an arithmetic coder whose mapping intervals are changed irregularly according to a keystream derived from chaotic map and plaintext. Performance and security of the scheme are also studied experimentally and theoretically in detail.

  4. On the Security of Provably Secure Multi-Receiver ID-Based Signcryption Scheme

    Science.gov (United States)

    Tan, Chik-How

    Recently, Duan and Cao proposed an multi-receiver identity-based signcryption scheme. They showed that their scheme is secure against adaptive chosen ciphertext attacks in the random oracle model. In this paper, we show that their scheme is in fact not secure against adaptive chosen ciphertext attacks under their defined security model.

  5. On the Security of Digital Signature Schemes Based on Error-Correcting Codes

    NARCIS (Netherlands)

    Xu, Sheng-bo; Doumen, J.M.; van Tilborg, Henk

    We discuss the security of digital signature schemes based on error-correcting codes. Several attacks to the Xinmei scheme are surveyed, and some reasons given to explain why the Xinmei scheme failed, such as the linearity of the signature and the redundancy of public keys. Another weakness is found

  6. Identity driven Capability based Access Control (ICAC) Scheme for the Internet of Things

    DEFF Research Database (Denmark)

    Mahalle, Parikshit N.; Anggorojati, Bayu; Prasad, Neeli R.

    2012-01-01

    Internet of Things (IoT) becomes discretionary part of everyday life. Scalability and manageability is daunting due to unbounded number of devices and services. Access control and authorization in IoT with least privilege is equally important to establish secure communication between multiple...... devices and services. In this paper, the concept of capability for access control is introduced where the identities of the involved devices are entrenched in the access capabilities. Identity driven capability based access control (ICAC) scheme presented in this paper helps to alleviate issues related...

  7. An Anonymous Voting Scheme based on Confirmation Numbers

    Science.gov (United States)

    Alam, Kazi Md. Rokibul; Tamura, Shinsuke; Taniguchi, Shuji; Yanase, Tatsuro

    This paper proposes a new electronic voting (e-voting) scheme that fulfills all the security requirements of e-voting i.e. privacy, accuracy, universal verifiability, fairness, receipt-freeness, incoercibility, dispute-freeness, robustness, practicality and scalability; usually some of which are found to be traded. When compared with other existing schemes, this scheme requires much more simple computations and weaker assumptions about trustworthiness of individual election authorities. The key mechanism is the one that uses confirmation numbers involved in individual votes to make votes verifiable while disabling all entities including voters themselves to know the linkages between voters and their votes. Many existing e-voting schemes extensively deploy zero-knowledge proof (ZKP) to achieve verifiability. However, ZKP is expensive and complicated. The confirmation numbers attain the verifiability requirement in a much more simple and intuitive way, then the scheme becomes scalable and practical.

  8. UPF based autonomous navigation scheme for deep space probe

    Institute of Scientific and Technical Information of China (English)

    Li Peng; Cui Hutao; Cui Pingyuan

    2008-01-01

    The autonomous "celestial navigation scheme" for deep space probe departing from the earth and the autonomous "optical navigation scheme" for encountering object celestial body are presented. Then, aiming at the conditions that large initial estimation errors and non-Gaussian distribution of state or measurement errors may exist in orbit determination process of the two phases, UPF (unscented particle filter) is introduced into the navigation schemes. By tackling nonlinear and non-Gaussian problems, UPF overcomes the accuracy influence brought by the traditional EKF (extended Kalman filter), UKF (unscented Kalman filter), and PF (particle filter) schemes in approximate treatment to nonlinear and non-Gaussian state model and measurement model. The numerical simulations demonstrate the feasibility and higher accuracy of the UPF navigation scheme.

  9. Hadoop-Based Distributed Sensor Node Management System

    National Research Council Canada - National Science Library

    Jung, In-Yong; Kim, Ki-Hyun; Han, Byong-John; Jeong, Chang-Sung

    2014-01-01

    ... and retrieve sensor data periodically from DFS. Additionally, it provides a flexible management scheme for sensor node by reconfiguring firmware or updating configurations and data formats of sensor nodes based on mapreduce framework...

  10. Block Access Token Renewal Scheme Based on Secret Sharing in Apache Hadoop

    Directory of Open Access Journals (Sweden)

    Su-Hyun Kim

    2014-07-01

    Full Text Available In a cloud computing environment, user data is encrypted and stored using a large number of distributed servers. Global Internet service companies such as Google and Yahoo have recognized the importance of Internet service platforms and conducted their own research and development to utilize large cluster-based cloud computing platform technologies based on low-cost commercial off-the-shelf nodes. Accordingly, as various data services are now allowed over a distributed computing environment, distributed management of big data has become a major issue. On the other hand, security vulnerability and privacy infringement due to malicious attackers or internal users can occur by means of various usage types of big data. In particular, various security vulnerabilities can occur in the block access token, which is used for the permission control of data blocks in Hadoop. To solve this problem, we have proposed a weight-applied XOR-based efficient distribution storage and recovery scheme in this paper. In particular, various security vulnerabilities can occur in the block access token, which is used for the permission control of data blocks in Hadoop. In this paper, a secret sharing-based block access token management scheme is proposed to overcome such security vulnerabilities.

  11. Key management schemes using routing information frames in secure wireless sensor networks

    Science.gov (United States)

    Kamaev, V. A.; Finogeev, A. G.; Finogeev, A. A.; Parygin, D. S.

    2017-01-01

    The article considers the problems and objectives of key management for data encryption in wireless sensor networks (WSN) of SCADA systems. The structure of the key information in the ZigBee network and methods of keys obtaining are discussed. The use of a hybrid key management schemes is most suitable for WSN. The session symmetric key is used to encrypt the sensor data, asymmetric keys are used to encrypt the session key transmitted from the routing information. Three algorithms of hybrid key management using routing information frames determined by routing methods and the WSN topology are presented.

  12. An Enhanced Leakage-Based Precoding Scheme for Multi-User Multi-Layer MIMO Systems

    OpenAIRE

    Yang, Chunliang

    2014-01-01

    In this paper, we propose an enhanced leakage-based precoding scheme, i.e., layer signal to leakage plus noise ratio (layer SLNR) scheme, for multi-user multi-layer MIMO systems. Specifically, the layer SLNR scheme incorporates the MIMO receiver structure into the precoder design procedure, which makes the formulation of signal power and interference / leakage power more accurate. Besides, the layer SLNR scheme not only takes into account the inter-layer interference from different users, but...

  13. Data base management study

    Science.gov (United States)

    1976-01-01

    Data base management techniques and applicable equipment are described. Recommendations which will assist potential NASA data users in selecting and using appropriate data base management tools and techniques are presented. Classes of currently available data processing equipment ranging from basic terminals to large minicomputer systems were surveyed as they apply to the needs of potential SEASAT data users. Cost and capabilities projections for this equipment through 1985 were presented. A test of a typical data base management system was described, as well as the results of this test and recommendations to assist potential users in determining when such a system is appropriate for their needs. The representative system tested was UNIVAC's DMS 1100.

  14. Market-Based Fisheries Management

    DEFF Research Database (Denmark)

    Høst, Jeppe Engset

    This book reveals how a privatization of fish resources has paved the way for a wide-reaching concentration and change in ownership. It is a thought-provoking contribution to the debate on the future of European fisheries and the possible solutions to overfishing in Europe. Readers will discover...... a timely, critical insight into the social, cultural and economic aspects and consequences of market-based fisheries management. The privatization of fish quotas in Denmark represents one of the most far-reaching and comprehensive privatization schemes of its kind and has been widely promoted as a market......-based system with innovative social safeguards. This work critically examines this privatization of fish resources, combining quantitative and qualitative material to provide new understanding of fish quotas and their social value. Scholars with an interest in privatization and the socio-economic aspects...

  15. A Robust and Efficient Trust Management Scheme for Peer-to-Peer Networks

    CERN Document Server

    Sen, Jaydip

    2010-01-01

    Studies on the large scale peer-to-peer (P2P) network like Gnutella have shown the presence of large number of free riders. Moreover, the open and decentralized nature of P2P network is exploited by malicious users who distribute unauthentic or harmful contents. Despite the existence of a number of trust management schemes in the literature for combating against free riding and distribution of malicious files, these mechanisms are not scalable due to their high computational, communication and storage overhead. These schemes also do not consider effect of trust management on quality-of-service (QoS) of the search. This paper presents a trust management scheme for P2P networks that minimizes distribution of spurious files by a novel technique called topology adaptation. It also reduces search time since most of the queries are resolved within the community of trustworthy peers. Simulation results indicate that the trust management overhead due to the pr oposed mechanism decreases considerably as the network to...

  16. An Efficient ECDSA-Based Signature Scheme for Wireless Networks

    Institute of Scientific and Technical Information of China (English)

    XU Zhong; DAI Guanzhong; YANG Deming

    2006-01-01

    Wired equivalent security is difficult to provide in wireless networks due to high dynamics, wireless link vulnerability, and decentralization. The Elliptic Curve Digital Signature Algorithm(ECDSA) has been applied to wireless networks because of its low computational cost and short key size, which reduces the overheads in a wireless environment. This study improves the ECDSA scheme by reducing its time complexity. The significant advantage of the algorithm is that our new scheme needs not to calculate modular inverse operation in the phases of signature generation and signature verification. Such an improvement makes the proposed scheme more efficient and secure.

  17. Approximation scheme based on effective interactions for stochastic gene regulation

    CERN Document Server

    Ohkubo, Jun

    2010-01-01

    Since gene regulatory systems contain sometimes only a small number of molecules, these systems are not described well by macroscopic rate equations; a master equation approach is needed for such cases. We develop an approximation scheme for dealing with the stochasticity of the gene regulatory systems. Using an effective interaction concept, original master equations can be reduced to simpler master equations, which can be solved analytically. We apply the approximation scheme to self-regulating systems with monomer or dimer interactions, and a two-gene system with an exclusive switch. The approximation scheme can recover bistability of the exclusive switch adequately.

  18. Agent-based power sharing scheme for active hybrid power sources

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Zhenhua [Department of Electrical and Computer Engineering, University of Miami, Coral Gables, FL 33146 (United States)

    2008-02-15

    The active hybridization technique provides an effective approach to combining the best properties of a heterogeneous set of power sources to achieve higher energy density, power density and fuel efficiency. Active hybrid power sources can be used to power hybrid electric vehicles with selected combinations of internal combustion engines, fuel cells, batteries, and/or supercapacitors. They can be deployed in all-electric ships to build a distributed electric power system. They can also be used in a bulk power system to construct an autonomous distributed energy system. An important aspect in designing an active hybrid power source is to find a suitable control strategy that can manage the active power sharing and take advantage of the inherent scalability and robustness benefits of the hybrid system. This paper presents an agent-based power sharing scheme for active hybrid power sources. To demonstrate the effectiveness of the proposed agent-based power sharing scheme, simulation studies are performed for a hybrid power source that can be used in a solar car as the main propulsion power module. Simulation results clearly indicate that the agent-based control framework is effective to coordinate the various energy sources and manage the power/voltage profiles. (author)

  19. Agent-based power sharing scheme for active hybrid power sources

    Science.gov (United States)

    Jiang, Zhenhua

    The active hybridization technique provides an effective approach to combining the best properties of a heterogeneous set of power sources to achieve higher energy density, power density and fuel efficiency. Active hybrid power sources can be used to power hybrid electric vehicles with selected combinations of internal combustion engines, fuel cells, batteries, and/or supercapacitors. They can be deployed in all-electric ships to build a distributed electric power system. They can also be used in a bulk power system to construct an autonomous distributed energy system. An important aspect in designing an active hybrid power source is to find a suitable control strategy that can manage the active power sharing and take advantage of the inherent scalability and robustness benefits of the hybrid system. This paper presents an agent-based power sharing scheme for active hybrid power sources. To demonstrate the effectiveness of the proposed agent-based power sharing scheme, simulation studies are performed for a hybrid power source that can be used in a solar car as the main propulsion power module. Simulation results clearly indicate that the agent-based control framework is effective to coordinate the various energy sources and manage the power/voltage profiles.

  20. An efficient and provable secure revocable identity-based encryption scheme.

    Directory of Open Access Journals (Sweden)

    Changji Wang

    Full Text Available Revocation functionality is necessary and crucial to identity-based cryptosystems. Revocable identity-based encryption (RIBE has attracted a lot of attention in recent years, many RIBE schemes have been proposed in the literature but shown to be either insecure or inefficient. In this paper, we propose a new scalable RIBE scheme with decryption key exposure resilience by combining Lewko and Waters' identity-based encryption scheme and complete subtree method, and prove our RIBE scheme to be semantically secure using dual system encryption methodology. Compared to existing scalable and semantically secure RIBE schemes, our proposed RIBE scheme is more efficient in term of ciphertext size, public parameters size and decryption cost at price of a little looser security reduction. To the best of our knowledge, this is the first construction of scalable and semantically secure RIBE scheme with constant size public system parameters.

  1. An efficient and provable secure revocable identity-based encryption scheme.

    Science.gov (United States)

    Wang, Changji; Li, Yuan; Xia, Xiaonan; Zheng, Kangjia

    2014-01-01

    Revocation functionality is necessary and crucial to identity-based cryptosystems. Revocable identity-based encryption (RIBE) has attracted a lot of attention in recent years, many RIBE schemes have been proposed in the literature but shown to be either insecure or inefficient. In this paper, we propose a new scalable RIBE scheme with decryption key exposure resilience by combining Lewko and Waters' identity-based encryption scheme and complete subtree method, and prove our RIBE scheme to be semantically secure using dual system encryption methodology. Compared to existing scalable and semantically secure RIBE schemes, our proposed RIBE scheme is more efficient in term of ciphertext size, public parameters size and decryption cost at price of a little looser security reduction. To the best of our knowledge, this is the first construction of scalable and semantically secure RIBE scheme with constant size public system parameters.

  2. An Identity-Based (IDB) Broadcast Encryption Scheme with Personalized Messages (BEPM)

    Science.gov (United States)

    Xu, Ke; Liao, Yongjian; Qiao, Li

    2015-01-01

    A broadcast encryption scheme with personalized messages (BEPM) is a scheme in which a broadcaster transmits not only encrypted broadcast messages to a subset of recipients but also encrypted personalized messages to each user individually. Several broadcast encryption (BE) schemes allow a broadcaster encrypts a message for a subset S of recipients with public keys and any user in S can decrypt the message with his/her private key. However, these BE schemes can not provide an efficient way to transmit encrypted personalized messages to each user individually. In this paper, we propose a broadcast encryption scheme with a transmission of personalized messages. Besides, the scheme is based on multilinear maps ensure constant ciphertext size and private key size of each user and the scheme can achieve statically security. More realistically, the scheme can be applied to the Conditional Access System (CAS) of pay television (pay-TV) efficiently and safely. PMID:26629817

  3. An Identity-Based (IDB) Broadcast Encryption Scheme with Personalized Messages (BEPM).

    Science.gov (United States)

    Xu, Ke; Liao, Yongjian; Qiao, Li; Liu, Zhangyun; Yang, Xiaowei

    2015-01-01

    A broadcast encryption scheme with personalized messages (BEPM) is a scheme in which a broadcaster transmits not only encrypted broadcast messages to a subset of recipients but also encrypted personalized messages to each user individually. Several broadcast encryption (BE) schemes allow a broadcaster encrypts a message for a subset S of recipients with public keys and any user in S can decrypt the message with his/her private key. However, these BE schemes can not provide an efficient way to transmit encrypted personalized messages to each user individually. In this paper, we propose a broadcast encryption scheme with a transmission of personalized messages. Besides, the scheme is based on multilinear maps ensure constant ciphertext size and private key size of each user and the scheme can achieve statically security. More realistically, the scheme can be applied to the Conditional Access System (CAS) of pay television (pay-TV) efficiently and safely.

  4. A Chaos-Based Encryption Scheme for DCT Precoded OFDM-Based Visible Light Communication Systems

    Directory of Open Access Journals (Sweden)

    Zhongpeng Wang

    2016-01-01

    Full Text Available This paper proposes a physical encryption scheme for discrete cosine transform (DCT precoded OFDM-based visible light communication systems by employing chaos scrambling. In the proposed encryption scheme, the Logistic map is adopted for the chaos mapping. The chaos scrambling strategy can allocate the two scrambling sequences to the real (I and imaginary (Q parts of OFDM frames according to the initial condition, which enhance the confidentiality of the physical layer. The simulation experimental results prove the efficiency of the proposed encryption method for DCT precoded OFDM-based VLC systems. The experimental results show that the proposed security scheme can protect the DCT precoded OFDM-based VLC from eavesdropper, while keeping the advantage of the DCT precoding technique, which can reduce the PAPR and improve the BER performance of OFDM-based VLC.

  5. A Rhythm-Based Authentication Scheme for Smart Media Devices

    Directory of Open Access Journals (Sweden)

    Jae Dong Lee

    2014-01-01

    Full Text Available In recent years, ubiquitous computing has been rapidly emerged in our lives and extensive studies have been conducted in a variety of areas related to smart devices, such as tablets, smartphones, smart TVs, smart refrigerators, and smart media devices, as a measure for realizing the ubiquitous computing. In particular, smartphones have significantly evolved from the traditional feature phones. Increasingly higher-end smartphone models that can perform a range of functions are now available. Smart devices have become widely popular since they provide high efficiency and great convenience for not only private daily activities but also business endeavors. Rapid advancements have been achieved in smart device technologies to improve the end users’ convenience. Consequently, many people increasingly rely on smart devices to store their valuable and important data. With this increasing dependence, an important aspect that must be addressed is security issues. Leaking of private information or sensitive business data due to loss or theft of smart devices could result in exorbitant damage. To mitigate these security threats, basic embedded locking features are provided in smart devices. However, these locking features are vulnerable. In this paper, an original security-locking scheme using a rhythm-based locking system (RLS is proposed to overcome the existing security problems of smart devices. RLS is a user-authenticated system that addresses vulnerability issues in the existing locking features and provides secure confidentiality in addition to convenience.

  6. Digital Signature Scheme Based on a New Hard Problem

    Directory of Open Access Journals (Sweden)

    Nikolay A. Moldovyan

    2008-07-01

    Full Text Available Factorizing composite number n=qr, where q and r are two large primes, and finding discrete logarithm modulo large prime number p are two difficult computational problems which are usually put into the base of different digital signature schemes (DSSes. This paper introduces a new hard computational problem that consists in finding the k th roots modulo large prime p=Nk2+1 where N is an even number and k is a prime with the length |k|≥160. Difficulty of the last problem is estimated as O(√k. It is proposed a new DSS with the public key xkmodp, where x is the private key. The signature corresponding to some message M represents a pair of the |p|$-bit numbers S and R calculated as follows: R=tk mod p and S=txf(R,Mmodp, where f(R, M is a compression function. The verification equation is Sk mod p=yf(R, MRmodp. The DSS is used to implement an efficient protocol for generating collective digital signatures.

  7. Noninvasive blood pressure measurement scheme based on optical fiber sensor

    Science.gov (United States)

    Liu, Xianxuan; Yuan, Xueguang; Zhang, Yangan

    2016-10-01

    Optical fiber sensing has many advantages, such as volume small, light quality, low loss, strong in anti-jamming. Since the invention of the optical fiber sensing technology in 1977, optical fiber sensing technology has been applied in the military, national defense, aerospace, industrial, medical and other fields in recent years, and made a great contribution to parameter measurement in the environment under the limited condition .With the rapid development of computer, network system, the intelligent optical fiber sensing technology, the sensor technology, the combination of computer and communication technology , the detection, diagnosis and analysis can be automatically and efficiently completed. In this work, we proposed a noninvasive blood pressure detection and analysis scheme which uses optical fiber sensor. Optical fiber sensing system mainly includes the light source, optical fiber, optical detector, optical modulator, the signal processing module and so on. wavelength optical signals were led into the optical fiber sensor and the signals reflected by the human body surface were detected. By comparing actual testing data with the data got by traditional way to measure the blood pressure we can establish models for predicting the blood pressure and achieve noninvasive blood pressure measurement by using spectrum analysis technology. Blood pressure measurement method based on optical fiber sensing system is faster and more convenient than traditional way, and it can get accurate analysis results in a shorter period of time than before, so it can efficiently reduce the time cost and manpower cost.

  8. Cap and trade schemes on waste management: A case study of the Landfill Allowance Trading Scheme (LATS) in England

    Energy Technology Data Exchange (ETDEWEB)

    Calaf-Forn, Maria, E-mail: mcalaf@ent.cat [Institut de Ciència i Tecnologia Ambientals (ICTA), Universitat Autònoma de Barcelona (UAB), E-08193 Bellaterra, Barcelona (Spain); ENT Environment and Management, Carrer Sant Joan 39, First Floor, E-08800 Vilanova i la Geltrú, Barcelona (Spain); Roca, Jordi [Departament de Teoria Econòmica, Universitat de Barcelona (UB), Diagonal, 696, E-08034 Barcelona (Spain); Puig-Ventosa, Ignasi [ENT Environment and Management, Carrer Sant Joan 39, First Floor, E-08800 Vilanova i la Geltrú, Barcelona (Spain)

    2014-05-01

    Highlights: • LATS has been effective to achieve a reduction of the amount of landfilled waste. • LATS has been one of the few environmental instruments for waste management with a cap and trade methodology. • LATS has achieved to increase recycling of the biodegradable and other waste fractions. - Abstract: The Landfill Allowance Trading Scheme (LATS) is one of the main instruments used in England to enforce the landfill diversion targets established in the Directive 1999/31/EC of the European Parliament and of the Council of 26 April 1999 on the landfill of waste (Landfill Directive). Through the LATS, biodegradable municipal waste (BMW) allowances for landfilling are allocated to each local authority, otherwise known as waste disposal authorities (WDAs). The quantity of landfill allowances received is expected to decrease continuously from 2005/06 to 2019/20 so as to meet the objectives of the Landfill Directive. To achieve their commitments, WDAs can exchange, buy, sell or transfer allowances among each other, or may re-profile their own allocation through banking and/or borrowing. Despite the goals for the first seven years – which included two target years (2005/06 and 2009/10) – being widely achieved (the average allocation of allowances per WDA was 22.9% higher than those finally used), market activity among WDAs was high and prices were not very stable. Results in terms of waste reduction and recycling levels have been satisfactory. The reduction of BMW landfilled (in percentage) was higher during the first seven years of the LATS period (2005/06–2011/12) (around 7% annually) than during the previous period (2001/02–2004/05) (4.2% annually). Since 2008, the significance of the LATS diminished because of an increase in the rate of the UK Landfill Tax. The LATS was suppressed after the 2012/13 target year, before what it was initially scheduled. The purpose of this paper is to describe the particularities of the LATS, analyse its performance as

  9. Arbitrated quantum signature scheme based on cluster states

    Science.gov (United States)

    Yang, Yu-Guang; Lei, He; Liu, Zhi-Chao; Zhou, Yi-Hua; Shi, Wei-Min

    2016-06-01

    Cluster states can be exploited for some tasks such as topological one-way computation, quantum error correction, teleportation and dense coding. In this paper, we investigate and propose an arbitrated quantum signature scheme with cluster states. The cluster states are used for quantum key distribution and quantum signature. The proposed scheme can achieve an efficiency of 100 %. Finally, we also discuss its security against various attacks.

  10. A Class of Key Predistribution Schemes Based on Orthogonal Arrays

    Institute of Scientific and Technical Information of China (English)

    Jun-Wu Dong; Ding-Yi Pei; Xue-Li Wang

    2008-01-01

    Pairwise key establishment is a fundamental security service in sensor networks; it enables sensor nodes to communicate securely with each other using cryptographic techniques. In order to ensure this security, many approaches have been proposed recently. One of them is to use key predistribution schemes for distributed sensor networks. The secure connectivity and resilience of the resulting sensor network are analyzed. This KPS constructed in our paper has some better properties than those of the existing schemes.

  11. Demand side management scheme in smart grid with cloud computing approach using stochastic dynamic programming

    Directory of Open Access Journals (Sweden)

    S. Sofana Reka

    2016-09-01

    Full Text Available This paper proposes a cloud computing framework in smart grid environment by creating small integrated energy hub supporting real time computing for handling huge storage of data. A stochastic programming approach model is developed with cloud computing scheme for effective demand side management (DSM in smart grid. Simulation results are obtained using GUI interface and Gurobi optimizer in Matlab in order to reduce the electricity demand by creating energy networks in a smart hub approach.

  12. A Lightweight Encryption Scheme Combined with Trust Management for Privacy-Preserving in Body Sensor Networks.

    Science.gov (United States)

    Guo, Ping; Wang, Jin; Ji, Sai; Geng, Xue Hua; Xiong, Neal N

    2015-12-01

    With the pervasiveness of smart phones and the advance of wireless body sensor network (BSN), mobile Healthcare (m-Healthcare), which extends the operation of Healthcare provider into a pervasive environment for better health monitoring, has attracted considerable interest recently. However, the flourish of m-Healthcare still faces many challenges including information security and privacy preservation. In this paper, we propose a secure and privacy-preserving framework combining with multilevel trust management. In our scheme, smart phone resources including computing power and energy can be opportunistically gathered to process the computing-intensive PHI (personal health information) during m-Healthcare emergency with minimal privacy disclosure. In specific, to leverage the PHI privacy disclosure and the high reliability of PHI process and transmission in m-Healthcare emergency, we introduce an efficient lightweight encryption for those users whose trust level is low, which is based on mix cipher algorithms and pair of plain text and cipher texts, and allow a medical user to decide who can participate in the opportunistic computing to assist in processing his overwhelming PHI data. Detailed security analysis and simulations show that the proposed framework can efficiently achieve user-centric privacy protection in m-Healthcare system.

  13. IDENTITY-BASED MULTISIGNATURE AND AGGREGATE SIGNATURE SCHEMES FROM M-TORSION GROUPS

    Institute of Scientific and Technical Information of China (English)

    Cheng Xiangguo; Liu Jingmei; Guo Lifeng; Wang Xinmei

    2006-01-01

    An identity-based multisignature scheme and an identity-based aggregate signature scheme are proposed in this paper. They are both from m-torsion groups on super-singular elliptic curves or hyper-elliptic curves and based on the recently proposed identity-based signature scheme of Cha and Cheon. Due to the sound properties of m-torsion groups and the base scheme, it turns out that our schemes are very simple and efficient. Both schemes are proven to be secure against adaptive chosen message attack in the random oracle model under the normal security notions with the assumption that the Computational Diffie-Hellman problem is hard in the m-torsion groups.

  14. DESIGN OF A DIGITAL SIGNATURE SCHEME BASED ON FACTORING AND DISCRETE LOGARITHMS

    Institute of Scientific and Technical Information of China (English)

    杨利英; 覃征; 胡广伍; 王志敏

    2004-01-01

    Objective Focusing on the security problem of authentication and confidentiality in the context of computer networks, a digital signature scheme was proposed based on the public key cryptosystem. Methods Firstly, the course of digital signature based on the public key cryptosystem was given. Then, RSA and ELGamal schemes were described respectively. They were the basis of the proposed scheme. Generalized ELGamal type signature schemes were listed. After comparing with each other, one scheme, whose Signature equation was (m+r)x=j+s modΦ(p) , was adopted in the designing. Results Based on two well-known cryptographic assumptions, the factorization and the discrete logarithms, a digital signature scheme was presented. It must be required that s' was not equal to p'q' in the signing procedure, because attackers could forge the signatures with high probabilities if the discrete logarithms modulo a large prime were solvable. The variable public key "e" is used instead of the invariable parameter "3" in Harns signature scheme to enhance the security. One generalized ELGamal type scheme made the proposed scheme escape one multiplicative inverse operation in the signing procedure and one modular exponentiation in the verification procedure. Conclusion The presented scheme obtains the security that Harn's scheme was originally claimed. It is secure if the factorization and the discrete logarithms are simultaneously unsolvable.

  15. CONSTRUCTION OF PROXY BLIND SIGNATURE SCHEME BASED ON MULTI-LINEAR TRANSFORM

    Institute of Scientific and Technical Information of China (English)

    Zhao Zemao; Liu Fengyu

    2004-01-01

    A general method of constructing proxy blind signature is proposed based on multilinear transform. Based on this method, the four proxy blind signature schemes are correspondently generated with four different signature equations, and each of them has four forms of variations of signs. Hence there are sixteen signatures in all, and all of them are proxy stronglyblind signature schemes. Furthermore, the two degenerated situations of multi-linear transform are discussed. Their corresponding proxy blind signature schemes are shown, too. But some schemes come from one of these degenerate situations are proxy weakly-blind signature scheme.The security for proposed scheme is analyzed in details. The results indicate that these signature schemes have many good properties such as unforgeability, distinguish-ability of proxy signature,non-repudiation and extensive value of application etc.

  16. An improved biometrics-based authentication scheme for telecare medical information systems.

    Science.gov (United States)

    Guo, Dianli; Wen, Qiaoyan; Li, Wenmin; Zhang, Hua; Jin, Zhengping

    2015-03-01

    Telecare medical information system (TMIS) offers healthcare delivery services and patients can acquire their desired medical services conveniently through public networks. The protection of patients' privacy and data confidentiality are significant. Very recently, Mishra et al. proposed a biometrics-based authentication scheme for telecare medical information system. Their scheme can protect user privacy and is believed to resist a range of network attacks. In this paper, we analyze Mishra et al.'s scheme and identify that their scheme is insecure to against known session key attack and impersonation attack. Thereby, we present a modified biometrics-based authentication scheme for TMIS to eliminate the aforementioned faults. Besides, we demonstrate the completeness of the proposed scheme through BAN-logic. Compared to the related schemes, our protocol can provide stronger security and it is more practical.

  17. Index-based reactive power compensation scheme for voltage regulation

    Science.gov (United States)

    Dike, Damian Obioma

    2008-10-01

    Increasing demand for electrical power arising from deregulation and the restrictions posed to the construction of new transmission lines by environment, socioeconomic, and political issues had led to higher grid loading. Consequently, voltage instability has become a major concern, and reactive power support is vital to enhance transmission grid performance. Improved reactive power support to distressed grid is possible through the application of relatively unfamiliar emerging technologies of "Flexible AC Transmission Systems (FACTS)" devices and "Distributed Energy Resources (DERS)." In addition to these infrastructure issues, a lack of situational awareness by system operators can cause major power outages as evidenced by the August 14, 2003 widespread North American blackout. This and many other recent major outages have highlighted the inadequacies of existing power system indexes. In this work, a novel "Index-based reactive compensation scheme" appropriate for both on-line and off-line computation of grid status has been developed. A new voltage stability index (Ls-index) suitable for long transmission lines was developed, simulated, and compared to the existing two-machine modeled L-index. This showed the effect of long distance power wheeling amongst regional transmission organizations. The dissertation further provided models for index modulated voltage source converters (VSC) and index-based load flow analysis of both FACTS and microgrid interconnected power systems using the Newton-Raphson's load flow model incorporated with multi-FACTS devices. The developed package has been made user-friendly through the embodiment of interactive graphical user interface and implemented on the IEEE 14, 30, and 300 bus systems. The results showed reactive compensation has system wide-effect, provided readily accessible system status indicators, ensured seamless DERs interconnection through new islanding modes and enhanced VSC utilization. These outcomes may contribute

  18. Analysis of Two-Phase Path Management Scheme for MPLS Traffic Engineering

    Science.gov (United States)

    Tamura, Hitomi; Kawahara, Kenji; Oie, Yuji

    Traffic Engineering (TE) is important for improving QoS in forwarding paths by efficient use of network resources. In fact, MPLS allows several detour paths to be (pre-)established for some source-destination pair as well as its primary path of minimum hops. Thus, we focus on a two-phase path management scheme using these two kinds of paths. In the first phase, each primary path is allocated to a flow on a specific source-destination pair if the path is not congested, i.e., if its utilization is less than some predetermined threshold; otherwise, as the second phase, one of the detour paths is allocated randomly if the path is available. Therefore, in this paper, we analytically evaluate this path management scheme by extending the M/M/c/c queueing system, and through some numerical results we investigate the impact of a threshold on the flow-blocking probability. Through some numerical results, we discuss the adequacy of the path management scheme for MPLS-TE.

  19. CS-DRM: A Cloud-Based SIM DRM Scheme for Mobile Internet

    Directory of Open Access Journals (Sweden)

    Liu Zhang

    2011-01-01

    Full Text Available With the rapid development and growth of the mobile industry, a considerable amount of mobile applications and services are available, which involve Internet scale data collections. Meanwhile, it has a tremendous impact on digital content providers as well as the mobile industry that a large number of digital content have been pirated and illegally distributed. Digital Rights Management (DRM aims at protecting digital contents from being abused through regulating their usage. Unfortunately, to the best of our knowledge, fewer of these DRM schemes are concerned with the cost of the servers in a DRM system when the number of users scales up, and consider benefits of content providers who can be seen as tenants of a content server. In this paper, we propose CS-DRM, a cloud-based SIM DRM scheme, for the mobile Internet. The SIM card is introduced into CS-DRM to both reduce the cost and provide higher security. Also, the characteristics of cloud computing enable CS-DRM to bring benefits for content providers, and well satisfy the performance requirements with low cost when the number of users increases significantly. Furthermore, we have implemented a prototype of our DRM scheme, which demonstrates that CS-DRM is efficient, secure, and practicable.

  20. QoS Based Capacity Enhancement for WCDMA Network with Coding Scheme

    Directory of Open Access Journals (Sweden)

    K.AYYAPPAN

    2010-03-01

    Full Text Available The wide-band code division multiple access (WCDMA based 3G and beyond cellular mobile wirelessnetworks are expected to provide a diverse range of multimedia services to mobile users withguaranteed quality of service (QoS. To serve diverse quality of service requirements of these networksit necessitates new radio resource management strategies for effective utilization of network resourceswith coding schemes. Call admission control (CAC is a significant component in wireless networks toguarantee quality of service requirements and also to enhance the network resilience. In this papercapacity enhancement for WCDMA network with convolutional coding scheme is discussed andcompared with block code and without coding scheme to achieve a better balance between resourceutilization and quality of service provisioning. The model of this network is valid for the real-time (RTand non-real-time (NRT services having different data rate. Simulation results demonstrate theeffectiveness of the network using convolutional code in terms of capacity enhancement and QoS of thevoice and video services.

  1. An arbitrated quantum signature scheme based on entanglement swapping with signer anonymity

    Science.gov (United States)

    Li, Wei; Fan, Ming-Yu; Wang, Guang-Wei

    2012-12-01

    In this paper an arbitrated quantum signature scheme based on entanglement swapping is proposed. In this scheme a message to be signed is coded with unitary operators. Combining quantum measurement with quantum encryption, the signer can generate the signature for a given message. Combining the entangled states generated by the TTP's Bell measurement with the signature information, the verifier can verify the authentication of a signature through a single quantum state measurement. Compared with previous schemes, our scheme is more efficient and less complex, furthermore, our scheme can ensure the anonymity of the signer.

  2. Two Group Signature Schemes with Multiple Strategies Based on Bilinear Pairings

    Directory of Open Access Journals (Sweden)

    Jianhua Zhu

    2009-10-01

    Full Text Available A group signature scheme and a threshold group signature scheme based on Bilinear Paring are proposed, there are multiple security strategies in these two schemes. These schemes have forward security which minimizes the damage caused by the exposure of any group member's signing key, and does not affect the past signatures generated by this member; meanwhile, ahead signature generated by a group member before the joining date can be prevented via this strategy. Moreover, this scheme support the group member revocable function efficiently and further has no requirement for time period limits.

  3. A chaotic map-based authentication scheme for telecare medicine information systems.

    Science.gov (United States)

    Hao, Xinhong; Wang, Jiantao; Yang, Qinghai; Yan, Xiaopeng; Li, Ping

    2013-04-01

    With the development of Internet, patients could enjoy health-care delivery services through telecare medicine information systems (TMIS) in their home. To control the access to remote medical servers' resources, many authentication schemes using smart cards have been proposed. However, the performance of these schemes is not satisfactory since modular exponential operations are used in these schemes. In the paper, we propose a chaotic map-based authentication scheme for telecare medicine information systems. The security and performance analysis shows our scheme is more suitable for TMIS.

  4. Convergence Improved Lax-Friedrichs Scheme Based Numerical Schemes and Their Applications in Solving the One-Layer and Two-Layer Shallow-Water Equations

    Directory of Open Access Journals (Sweden)

    Xinhua Lu

    2015-01-01

    Full Text Available The first-order Lax-Friedrichs (LF scheme is commonly used in conjunction with other schemes to achieve monotone and stable properties with lower numerical diffusion. Nevertheless, the LF scheme and the schemes devised based on it, for example, the first-order centered (FORCE and the slope-limited centered (SLIC schemes, cannot achieve a time-step-independence solution due to the excessive numerical diffusion at a small time step. In this work, two time-step-convergence improved schemes, the C-FORCE and C-SLIC schemes, are proposed to resolve this problem. The performance of the proposed schemes is validated in solving the one-layer and two-layer shallow-water equations, verifying their capabilities in attaining time-step-independence solutions and showing robustness of them in resolving discontinuities with high-resolution.

  5. INVESTIGATION OF UPLINK RADIO RESOURCE MANAGEMENT SCHEMES FOR MULTI-SERVICES IN TDD-CDMA SYSTEMS EMPLOYING SMART ANTENNAS

    Institute of Scientific and Technical Information of China (English)

    Peng Mugen; Wang Wenbo

    2006-01-01

    In this paper, a theoretical analysis of Time Division Duplex-Code Division Multiple Access (TDD-CDMA) uplink capacity constraint is presented when employing the smart antenna techniques. The evaluation formulations of capacity and load for multi-services are proposed. In order to maximize the throughput, the objective of optimization is proposed, and an advanced uplink resource management algorithm is developed. The proposed algorithm based on the least interference admission control scheme focuses on the maximum throughput for the circuit switched multi-services. The simulation results show that the proposed strategy has a significant improvement in throughput when the optimum admission control threshold is set.

  6. A New Digital Signature Scheme Based on Factoring and Discrete Logarithms

    Directory of Open Access Journals (Sweden)

    E. S. Ismail

    2008-01-01

    Full Text Available Problem statement: A digital signature scheme allows one to sign an electronic message and later the produced signature can be validated by the owner of the message or by any verifier. Most of the existing digital signature schemes were developed based on a single hard problem like factoring, discrete logarithm, residuosity or elliptic curve discrete logarithm problems. Although these schemes appear secure, one day in a near future they may be exploded if one finds a solution of the single hard problem. Approach: To overcome this problem, in this study, we proposed a new signature scheme based on multiple hard problems namely factoring and discrete logarithms. We combined the two problems into both signing and verifying equations such that the former depends on two secret keys whereas the latter depends on two corresponding public keys. Results: The new scheme was shown to be secure against the most five considering attacks for signature schemes. The efficiency performance of our scheme only requires 1203Tmul+Th time complexity for signature generation and 1202Tmul+Th time complexity for verification generation and this magnitude of complexity is considered minimal for multiple hard problems-like signature schemes. Conclusions: The new signature scheme based on multiple hard problems provides longer and higher security level than that scheme based on one problem. This is because no enemy can solve multiple hard problems simultaneously.

  7. 基于动态多簇密钥管理模型的安全数据聚合方案%Data Aggregation Security Solution Based on Key Management Scheme of Dynamic Multi-cluster

    Institute of Scientific and Technical Information of China (English)

    雷凤宇; 秦玉化; 陈文鑫; 陈晶

    2011-01-01

    军事领域需要强有力的安全措施,但由于环境恶劣,缺乏物理保护,难以展开固定的通信设施.设计了一种基于身份的动态多簇密钥管理模型.该模型以簇为单位进行密钥管理,每个成员节点只需存储本簇的公钥因子矩阵,极大地节省了密钥存储空间,且可抵抗同谋攻击;密钥分发过程安全高效,节点加入和退出时密钥更新开销小;不依赖可信第三方便可实现身份认证,且不需要固定基础设施的支持.基于该模型提出了一种安全数据聚合方案.列举了部分可以抵御的攻击;讨论了该方案握手过程需要消耗的能量.结果显示,在新模型下将公钥密码体制用于无线传感器网络是可行的.%A dynamic multiple cluster key management model based on identity was designed in wireless sensor net work. The key management in the model is cluster-based. Every node in the network is just required to store its private key and the public key factor matrix of the cluster that it belongs tot which consumes little storage space and can resist the collusion attack. The key distribution is secure and effective. It costs little during the node joining and leaving. And it realizes the identity authentication independent of the third party and has no use for infrastructure to sustain the key distribution center. A secure data aggregation solution based on the model was proposed. Security of the proposed solu tion was analyzed and some attacks that can be resisted were listed. The energy consumption during the handshaking process was discussed .which indicates that it is feasible to use the identity-based cryptography in the wireless sensor networks.

  8. One-step discrimination scheme on N-particle Greenberger-Horne-Zeilinger bases

    Institute of Scientific and Technical Information of China (English)

    Wang Xin-Wen; Liu Xiang; Fang Mao-Fa

    2007-01-01

    We present an experimentally feasible one-step discrimination scheme on Bell bases with trapped ions, and then generalize it to the case of N-ion Greenberger-Horne-Zeilinger (GHZ) bases. In the scheme, all the orthogonal and complete N-ion GHZ internal states can be exactly discriminated only by one step, and thus it takes very short time. Moreover, the scheme is insensitive to thermal motion and dose not require the individual addressing of the ions. The Bell-state and GHZ-state one-step discrimination scheme can be widely used in quantum information processing based on ion-trap set-up.

  9. An efficient and secure attribute based signcryption scheme with LSSS access structure.

    Science.gov (United States)

    Hong, Hanshu; Sun, Zhixin

    2016-01-01

    Attribute based encryption (ABE) and attribute based signature (ABS) provide flexible access control with authentication for data sharing between users, but realizing both functions will bring about too much computation burden. In this paper, we combine the advantages of CP-ABE with ABS and propose a ciphertext policy attribute based signcryption scheme. In our scheme, only legal receivers can decrypt the ciphertext and verify the signature signed by data owner. Furthermore, we use linear secret sharing scheme instead of tree structure to avoid the frequent calls of recursive algorithm. By security and performance analysis, we prove that our scheme is secure as well as gains higher efficiency.

  10. A training-based scheme for communicating over unknown channels with feedback

    CERN Document Server

    Mahajan, Aditya

    2009-01-01

    We consider communication with noiseless feedback over a channel that is either BSC(p) or BSC(1-p); neither the transmitter nor the receiver know which one. The parameter $p \\in [0, 1/2]$ is known to both. We propose a variable length training-based scheme for this channel. The error exponent of this scheme is within a constant fraction of the best possible error exponent. Thus, contrary to popular belief, variable length training-based schemes need not have poor error exponents. Moreover, training-based schemes can preserve the main advantage of feedback -- an error exponent with non-zero slope at rates close to capacity.

  11. Novel Sequence Number Based Secure Authentication Scheme for Wireless LANs

    Institute of Scientific and Technical Information of China (English)

    Rajeev Singh; Teek Parval Sharma

    2015-01-01

    Authentication per frame is an implicit necessity for security in wireless local area networks (WLANs). We propose a novel per frame secure authentication scheme which provides authentication to data frames in WLANs. The scheme involves no cryptographic overheads for authentication of frames. It utilizes the sequence number of the frame along with the authentication stream generators for authentication. Hence, it requires no extra bits or messages for the authentication purpose and also no change in the existing frame format is required. The scheme provides authentication by modifying the sequence number of the frame at the sender, and that the modification is verified at the receiver. The modified sequence number is protected by using the XOR operation with a random number selected from the random stream. The authentication is lightweight due to the fact that it requires only trivial arithmetic operations like the subtraction and XOR operation.

  12. Research on road topology based mobility prediction schemes

    Institute of Scientific and Technical Information of China (English)

    Chen Lin; Chen Hongzhong; Jiang Changjun

    2007-01-01

    Geographic routing has been introduced in mobile ad hoc networks and sensor networks . But its performance suffers greatly from mobility- induced location errors that can cause Lost Link (LLNK) and LOOP problems. Thus various mobility prediction algorithms have been proposed to mitigate the errors, but sometimes their prediction errors are substantial . A novel mobility prediction technique that incorporates both mobile positioning information and road topology knowledge was presented. Furthermore, the performance of the scheme was evaluated via simulations , along with two other schemes , namely , Linear Velocity Prediction ( LVP) and Weighted Velocity Prediction ( WVP) for comparison purpose . The results of simulation under Manhattan mobility model show that the proposed scheme could track the movement of a node well and hence provide noticeable improvement over LVP and MVP.

  13. A Policy Based Scheme for Combined Data Security in Mobile Ad hoc Networks

    Directory of Open Access Journals (Sweden)

    S. K. Srivatsa

    2012-01-01

    Full Text Available Problem statement: In Mobile Ad hoc Networks (MANET routing protocols, we require a network-level or link layer security. Since without appropriate security provisions, the MANETs is subjected to attacks like network traffic, replay transmissions, manipulate packet headers and redirect routing messages. In order to address these needs, a policy based network management system that provides the capability to express network requirements is required. Approach: In this study, we propose a policy based scheme for combined data security which focuses mainly on three policies: Integrity, authentication and Confidentiality. For providing security not only to data, but also for routing information, we calculate the trust indexes of the nodes and the route is selected according to the trust value which improves integrity. Then in order to provide authentication, we propose a Distributed Certificate Authority (DCA technique in which multiple DCA is required to construct a certificate. Next we propose an RSA based novel encryption mechanism in order to provide Confidentiality among the nodes. Thus, the desired level of security is provided by the system based on the policy of the user by executing the corresponding security modules. Results: By simulation results, we show that this scheme provides a combined data security in MANETs and can be used efficiently. Conclusion: Our proposed combined data security policy provides complete protection for the data in MANET communications.

  14. Feedback-based Intra Refresh Scheme for Wireless Video Transmission

    Institute of Scientific and Technical Information of China (English)

    FENGXiubo; XIEJianying

    2004-01-01

    This paper investigates the intra refresh techniques for video transmission in wireless scenario. Twostate Markov model is proposed to simulate the fading wireless channel. Taking feedback information into account, we analyze the channel distortion due to the burst errors. An improved intra refresh scheme is then proposed for optimal selection of coding mode for each Macroblock (MB) in rate-distortion framework. The propo sedscheme can stop error propagation and reduce channel distortion effectively. Simulations using TMN10 show that our scheme obtains improved performance with respect to error resilience for wireless video communication.

  15. The Lifting Scheme Based on the Second Generation Wavelets

    Institute of Scientific and Technical Information of China (English)

    FENG Hui; GUO Lanying; XIAO Jinsheng

    2006-01-01

    The lifting scheme is a custom-design construction of Biorthogonal wavelets, a fast and efficient method to realize wavelet transform, which provides a wider range of application and efficiently reduces the computing time with its particular frame. This paper aims at introducing the second generation wavelets, begins with traditional Mallat algorithms, illustrates the lifting scheme and brings out the detail steps in the construction of Biorthogonal wavelets. Because of isolating the degrees of freedom remaining the biorthogonality relations, we can fully control over the lifting operators to design the wavelet for a particular application, such as increasing the number of the vanishing moments.

  16. A secure quantum group signature scheme based on Bell states

    Science.gov (United States)

    Zhang, Kejia; Song, Tingting; Zuo, Huijuan; Zhang, Weiwei

    2013-04-01

    In this paper, we propose a new secure quantum group signature with Bell states, which may have applications in e-payment system, e-government, e-business, etc. Compared with the recent quantum group signature protocols, our scheme is focused on the most general situation in practice, i.e. only the arbitrator is trusted and no intermediate information needs to be stored in the signing phase to ensure the security. Furthermore, our scheme has achieved all the characteristics of group signature—anonymity, verifiability, traceability, unforgetability and undeniability, by using some current developed quantum and classical technologies. Finally, a feasible security analysis model for quantum group signature is presented.

  17. A New Digital Signature Scheme Based on Mandelbrot and Julia Fractal Sets

    Directory of Open Access Journals (Sweden)

    M. A. Alia

    2007-01-01

    Full Text Available This paper describes a new cryptographic digital signature scheme based on Mandelbrot and Julia fractal sets. Having fractal based digital signature scheme is possible due to the strong connection between the Mandelbrot and Julia fractal sets. The link between the two fractal sets used for the conversion of the private key to the public key. Mandelbrot fractal function takes the chosen private key as the input parameter and generates the corresponding public-key. Julia fractal function then used to sign the message with receiver's public key and verify the received message based on the receiver's private key. The propose scheme was resistant against attacks, utilizes small key size and performs comparatively faster than the existing DSA, RSA digital signature scheme. Fractal digital signature scheme was an attractive alternative to the traditional number theory digital signature scheme.

  18. Cryptanalysis And Further Improvement Of A Biometric-Based Remote User Authentication Scheme Using Smart Cards

    Directory of Open Access Journals (Sweden)

    Ashok Kumar Das

    2011-03-01

    Full Text Available Recently, Li et al. proposed a secure biometric-based remote user authentication scheme using smartcards to withstand the security flaws of Li-Hwang’s efficient biometric-based remote user authenticationscheme using smart cards. Li et al.’s scheme is based on biometrics verification, smart card and one-wayhash function, and it also uses the random nonce rather than a synchronized clock, and thus it is efficientin computational cost and more secure than Li-Hwang’s scheme. Unfortunately, in this paper we showthat Li et al.’s scheme still has some security weaknesses in their design. In order to withstand thoseweaknesses in their scheme, we further propose an improvement of their scheme so that the improvedscheme always provides proper authentication and as a result, it establishes a session key between theuser and the server at the end of successful user authentication.

  19. An Energy-Efficient Secure Routing and Key Management Scheme for Mobile Sinks in Wireless Sensor Networks Using Deployment Knowledge

    Directory of Open Access Journals (Sweden)

    Le Xuan Hung

    2008-12-01

    Full Text Available For many sensor network applications such as military or homeland security, it is essential for users (sinks to access the sensor network while they are moving. Sink mobility brings new challenges to secure routing in large-scale sensor networks. Previous studies on sink mobility have mainly focused on efficiency and effectiveness of data dissemination without security consideration. Also, studies and experiences have shown that considering security during design time is the best way to provide security for sensor network routing. This paper presents an energy-efficient secure routing and key management for mobile sinks in sensor networks, called SCODEplus. It is a significant extension of our previous study in five aspects: (1 Key management scheme and routing protocol are considered during design time to increase security and efficiency; (2 The network topology is organized in a hexagonal plane which supports more efficiency than previous square-grid topology; (3 The key management scheme can eliminate the impacts of node compromise attacks on links between non-compromised nodes; (4 Sensor node deployment is based on Gaussian distribution which is more realistic than uniform distribution; (5 No GPS or like is required to provide sensor node location information. Our security analysis demonstrates that the proposed scheme can defend against common attacks in sensor networks including node compromise attacks, replay attacks, selective forwarding attacks, sinkhole and wormhole, Sybil attacks, HELLO flood attacks. Both mathematical and simulation-based performance evaluation show that the SCODEplus significantly reduces the communication overhead, energy consumption, packet delivery latency while it always delivers more than 97 percent of packets successfully.

  20. A Provably-Secure ECC-Based Authentication Scheme for Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Junghyun Nam

    2014-11-01

    Full Text Available A smart-card-based user authentication scheme for wireless sensor networks (in short, a SUA-WSN scheme is designed to restrict access to the sensor data only to users who are in possession of both a smart card and the corresponding password. While a significant number of SUA-WSN schemes have been suggested in recent years, their intended security properties lack formal definitions and proofs in a widely-accepted model. One consequence is that SUA-WSN schemes insecure against various attacks have proliferated. In this paper, we devise a security model for the analysis of SUA-WSN schemes by extending the widely-accepted model of Bellare, Pointcheval and Rogaway (2000. Our model provides formal definitions of authenticated key exchange and user anonymity while capturing side-channel attacks, as well as other common attacks. We also propose a new SUA-WSN scheme based on elliptic curve cryptography (ECC, and prove its security properties in our extended model. To the best of our knowledge, our proposed scheme is the first SUA-WSN scheme that provably achieves both authenticated key exchange and user anonymity. Our scheme is also computationally competitive with other ECC-based (non-provably secure schemes.

  1. A soft-hard combination-based cooperative spectrum sensing scheme for cognitive radio networks.

    Science.gov (United States)

    Do, Nhu Tri; An, Beongku

    2015-02-13

    In this paper we propose a soft-hard combination scheme, called SHC scheme, for cooperative spectrum sensing in cognitive radio networks. The SHC scheme deploys a cluster based network in which Likelihood Ratio Test (LRT)-based soft combination is applied at each cluster, and weighted decision fusion rule-based hard combination is utilized at the fusion center. The novelties of the SHC scheme are as follows: the structure of the SHC scheme reduces the complexity of cooperative detection which is an inherent limitation of soft combination schemes. By using the LRT, we can detect primary signals in a low signal-to-noise ratio regime (around an average of -15 dB). In addition, the computational complexity of the LRT is reduced since we derive the closed-form expression of the probability density function of LRT value. The SHC scheme also takes into account the different effects of large scale fading on different users in the wide area network. The simulation results show that the SHC scheme not only provides the better sensing performance compared to the conventional hard combination schemes, but also reduces sensing overhead in terms of reporting time compared to the conventional soft combination scheme using the LRT.

  2. An adjoint-based scheme for eigenvalue error improvement

    Energy Technology Data Exchange (ETDEWEB)

    Merton, S.R.; Smedley-Stevenson, R.P., E-mail: Simon.Merton@awe.co.uk, E-mail: Richard.Smedley-Stevenson@awe.co.uk [AWE plc, Berkshire (United Kingdom); Pain, C.C.; El-Sheikh, A.H.; Buchan, A.G., E-mail: c.pain@imperial.ac.uk, E-mail: a.el-sheikh@imperial.ac.uk, E-mail: andrew.buchan@imperial.ac.uk [Department of Earth Science and Engineering, Imperial College, London (United Kingdom)

    2011-07-01

    A scheme for improving the accuracy and reducing the error in eigenvalue calculations is presented. Using a rst order Taylor series expansion of both the eigenvalue solution and the residual of the governing equation, an approximation to the error in the eigenvalue is derived. This is done using a convolution of the equation residual and adjoint solution, which is calculated in-line with the primal solution. A defect correction on the solution is then performed in which the approximation to the error is used to apply a correction to the eigenvalue. The method is shown to dramatically improve convergence of the eigenvalue. The equation for the eigenvalue is shown to simplify when certain normalizations are applied to the eigenvector. Two such normalizations are considered; the rst of these is a fission-source type of normalisation and the second is an eigenvector normalisation. Results are demonstrated on a number of demanding elliptic problems using continuous Galerkin weighted nite elements. Moreover, the correction scheme may also be applied to hyperbolic problems and arbitrary discretization. This is not limited to spatial corrections and may be used throughout the phase space of the discrete equation. The applied correction not only improves fidelity of the calculation, it allows assessment of the reliability of numerical schemes to be made and could be used to guide mesh adaption algorithms or to automate mesh generation schemes. (author)

  3. ECC Based Threshold Decryption Scheme and Its Application in Web Security

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xian-feng; ZHANG Feng; QIN Zhi-guang; LIU Jin-de

    2004-01-01

    The threshold cryptography provides a new approach to building intrusion tolerance applications. In this paper, a threshold decryption scheme based elliptic curve cryptography is presented. A zero-knowledge test approach based on elliptic curve cryptography is designed. The application of these techniques in Web security is studied. Performance analysis shows that our scheme is characterized by excellent security as well as high efficiency.

  4. UNIFIED COMPUTATION OF FLOW WITH COMPRESSIBLE AND INCOMPRESSIBLE FLUID BASED ON ROE'S SCHEME

    Institute of Scientific and Technical Information of China (English)

    HUANG Dian-gui

    2006-01-01

    A unified numerical scheme for the solutions of the compressible and incompressible Navier-Stokes equations is investigated based on a time-derivative preconditioning algorithm. The primitive variables are pressure, velocities and temperature. The time integration scheme is used in conjunction with a finite volume discretization. The preconditioning is coupled with a high order implicit upwind scheme based on the definition of a Roe's type matrix. Computational capabilities are demonstrated through computations of high Mach number, middle Mach number, very low Mach number, and incompressible flow. It has also been demonstrated that the discontinuous surface in flow field can be captured for the implementation Roe's scheme.

  5. Performance Analysis of Virtual MIMO Relaying Schemes Based on Detect–Split–Forward

    KAUST Repository

    Al-Basit, Suhaib M.

    2014-10-29

    © 2014, Springer Science+Business Media New York. Virtual multi-input multi-output (vMIMO) schemes in wireless communication systems improve coverage, throughput, capacity, and quality of service. In this paper, we propose three uplink vMIMO relaying schemes based on detect–split–forward (DSF). In addition, we investigate the effect of several physical parameters such as distance, modulation type and number of relays. Furthermore, an adaptive vMIMO DSF scheme based on VBLAST and STBC is proposed. In order to do that, we provide analytical tools to evaluate the performance of the propose vMIMO relaying scheme.

  6. A HIPAA-compliant key management scheme with revocation of authorization.

    Science.gov (United States)

    Lee, Wei-Bin; Lee, Chien-Ding; Ho, Kevin I-J

    2014-03-01

    Patient control over electronic protected health information (ePHI) is one of the major concerns in the Health Insurance and Accountability Act (HIPAA). In this paper, a new key management scheme is proposed to facilitate control by providing two functionalities. First, a patient can authorize more than one healthcare institute within a designated time period to access his or her ePHIs. Second, a patient can revoke authorization and add new authorized institutes at any time as necessary. In the design, it is not required to re-encrypt ePHIs for adding and revoking authorizations, and the implementation is time- and cost-efficient. Consent exception is also considered by the proposed scheme.

  7. Evidence-based management.

    Science.gov (United States)

    Pfeffer, Jeffrey; Sutton, Robert I

    2006-01-01

    For the most part, managers looking to cure their organizational ills rely on obsolete knowledge they picked up in school, long-standing but never proven traditions, patterns gleaned from experience, methods they happen to be skilled in applying, and information from vendors. They could learn a thing or two from practitioners of evidence-based medicine, a movement that has taken the medical establishment by storm over the past decade. A growing number of physicians are eschewing the usual, flawed resources and are instead identifying, disseminating, and applying research that is soundly conducted and clinically relevant. It's time for managers to do the same. The challenge is, quite simply, to ground decisions in the latest and best knowledge of what actually works. In some ways, that's more difficult to do in business than in medicine. The evidence is weaker in business; almost anyone can (and many people do) claim to be a management expert; and a motley crew of sources--Shakespeare, Billy Graham,Jack Welch, Attila the Hunare used to generate management advice. Still, it makes sense that when managers act on better logic and strong evidence, their companies will beat the competition. Like medicine, management is learned through practice and experience. Yet managers (like doctors) can practice their craft more effectively if they relentlessly seek new knowledge and insight, from both inside and outside their companies, so they can keep updating their assumptions, skills, and knowledge.

  8. Identity based Encryption and Biometric Authentication Scheme for Secure Data Access in Cloud Computing

    DEFF Research Database (Denmark)

    Cheng, Hongbing; Rong, Chunming; Tan, Zheng-Hua

    2012-01-01

    Cloud computing will be a main information infrastructure in the future; it consists of many large datacenters which are usually geographically distributed and heterogeneous. How to design a secure data access for cloud computing platform is a big challenge. In this paper, we propose a secure data...... distribution, feature template creation, cloud data processing and secure data access control. Finally, we compare the proposed scheme with other schemes through comprehensive analysis and simulation. The results show that the proposed data access scheme is feasible and secure for cloud computing....... access scheme based on identity-based encryption and biometric authentication for cloud computing. Firstly, we describe the security concern of cloud computing and then propose an integrated data access scheme for cloud computing, the procedure of the proposed scheme include parameter setup, key...

  9. NOVEL MULTIMEDIA TRAFFIC MODELING BASED CAC SCHEME FOR CDMA COMMUNICATION SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    Zhang Dandan; Fang Xuming; Zhu Longjie

    2007-01-01

    As the radio spectrum is a very scarce resource, the Call Admission Control (CAC) is one of the most important parts in radio resource management. The Code Division Multiple Access (CDMA)based next generation wireless communications systems will support the transmission of multimedia traffic, such as voice, video and data, thus the CAC, which can support the multimedia traffic and guarantee the Quality of Service (QoS) of different traffic, has gained broad attention. In this paper, a novel multimedia traffic modeling method and a corresponding dynamic QoS based CAC are proposed.The analysis and simulation results show that the proposed CAC scheme can guarantee the QoS to different traffic demand, and improve the system performance significantly.

  10. An Identity Based Strong Bi-Designated Verifier (t, n) Threshold Proxy Signature Scheme

    OpenAIRE

    lal, Sunder; Verma, Vandani

    2008-01-01

    Proxy signature schemes have been invented to delegate signing rights. The paper proposes a new concept of Identify Based Strong Bi-Designated Verifier threshold proxy signature (ID-SBDVTPS) schemes. Such scheme enables an original signer to delegate the signature authority to a group of 'n' proxy signers with the condition that 't' or more proxy signers can cooperatively sign messages on behalf of the original signer and the signatures can only be verified by any two designated verifiers and...

  11. Error Robust H.264 Video Transmission Schemes Based on Multi-frame

    Institute of Scientific and Technical Information of China (English)

    余红斌; 余松煜; 王慈

    2004-01-01

    Multi-frame coding is supported by the emerging H. 264. It is important for the enhancement of both coding efficiency and error robustness. In this paper, error resilient schemes for H. 264 based on multi-frame were investigated. Error robust H. 264 video transmission schemes were introduced for the applications with and without a feedback channel. The experimental results demonstrate the effectiveness of the proposed schemes.

  12. A Quantum Proxy Weak Blind Signature Scheme Based on Controlled Quantum Teleportation

    Science.gov (United States)

    Cao, Hai-Jing; Yu, Yao-Feng; Song, Qin; Gao, Lan-Xiang

    2015-04-01

    Proxy blind signature is applied to the electronic paying system, electronic voting system, mobile agent system, security of internet, etc. A quantum proxy weak blind signature scheme is proposed in this paper. It is based on controlled quantum teleportation. Five-qubit entangled state functions as quantum channel. The scheme uses the physical characteristics of quantum mechanics to implement message blinding, so it could guarantee not only the unconditional security of the scheme but also the anonymity of the messages owner.

  13. Efficient Identity Based Signcryption Scheme with Public Verifiability and Forward Security

    Institute of Scientific and Technical Information of China (English)

    LEI Fei-yu; CHEN Wen; CHEN Ke-fei; MA Chang-she

    2005-01-01

    In this paper, we point out that Libert and Quisquater's signcryption scheme cannot provide public verifiability. Then we present a new identity based signcryption scheme using quadratic residue and pairings over elliptic curves. It combines the functionalities of both public verifiability and forward security at the same time. Under the Bilinear Diffie-Hellman and quadratic residue assumption, we describe the new scheme that is more secure and can be somewhat more efficient than Libert and Quisquater's one.

  14. Remote sensing image compression method based on lift scheme wavelet transform

    Science.gov (United States)

    Tao, Hongjiu; Tang, Xinjian; Liu, Jian; Tian, Jinwen

    2003-06-01

    Based on lifting scheme and the construction theorem of the integer Haar wavelet and biorthogonal wavelet, we propose a new integer wavelet transform construct method on the basis of lift scheme after introduciton of constructing specific-demand biorthogonal wavelet transform using Harr wavelet and Lazy wavelet. In this paper, we represent the method and algorithm of the lifting scheme, and we also give mathematical formulation on this method and experimental results as well.

  15. Chaos-based partial image encryption scheme based on linear fractional and lifting wavelet transforms

    Science.gov (United States)

    Belazi, Akram; Abd El-Latif, Ahmed A.; Diaconu, Adrian-Viorel; Rhouma, Rhouma; Belghith, Safya

    2017-01-01

    In this paper, a new chaos-based partial image encryption scheme based on Substitution-boxes (S-box) constructed by chaotic system and Linear Fractional Transform (LFT) is proposed. It encrypts only the requisite parts of the sensitive information in Lifting-Wavelet Transform (LWT) frequency domain based on hybrid of chaotic maps and a new S-box. In the proposed encryption scheme, the characteristics of confusion and diffusion are accomplished in three phases: block permutation, substitution, and diffusion. Then, we used dynamic keys instead of fixed keys used in other approaches, to control the encryption process and make any attack impossible. The new S-box was constructed by mixing of chaotic map and LFT to insure the high confidentiality in the inner encryption of the proposed approach. In addition, the hybrid compound of S-box and chaotic systems strengthened the whole encryption performance and enlarged the key space required to resist the brute force attacks. Extensive experiments were conducted to evaluate the security and efficiency of the proposed approach. In comparison with previous schemes, the proposed cryptosystem scheme showed high performances and great potential for prominent prevalence in cryptographic applications.

  16. DWT-Based Robust Color Image Watermarking Scheme

    Institute of Scientific and Technical Information of China (English)

    Liu Lianshan; Li Renhou; Gao Qi

    2005-01-01

    A scheme of embedding an encrypted watermark into the green component of a color image is proposed. The embedding process is implemented in the discrete wavelet transformation (DWT) domain. The original binary watermark image is firstly encrypted through scrambling technique, and then spread with two orthogonal pseudo-random sequences whose mean values are equal to zero, and finally embedded into the DWT low frequency sub-band of green components. The coefficients whose energies are larger than the others are selected to hide watermark, and the hidden watermark strength is determined by the energy ratio between the selected coefficients energies and the mean energy of the subband. The experiment results demonstrate that the proposed watermarking scheme is very robust against the attacks such as additive noise, low-pass filtering, scaling, cropping image, row ( or column ) deleting, and JPEG compression.

  17. Investigation into Text Classification With Kernel Based Schemes

    Science.gov (United States)

    2010-03-01

    classification/categorization applications. The text database considered in this study was collected from the IEEE Xplore database website [2]. The...database considered in this study was collected from the IEEE Xplore database website [2]. The documents collected were limited to Electrical engineering...Linear Discriminant Analysis (LDA) scheme. Titles, along with abstracts from IEEE journal articles published between 1990 and 1999 with specific key

  18. A continuous and prognostic convection scheme based on buoyancy, PCMT

    Science.gov (United States)

    Guérémy, Jean-François; Piriou, Jean-Marcel

    2016-04-01

    A new and consistent convection scheme (PCMT: Prognostic Condensates Microphysics and Transport), providing a continuous and prognostic treatment of this atmospheric process, is described. The main concept ensuring the consistency of the whole system is the buoyancy, key element of any vertical motion. The buoyancy constitutes the forcing term of the convective vertical velocity, which is then used to define the triggering condition, the mass flux, and the rates of entrainment-detrainment. The buoyancy is also used in its vertically integrated form (CAPE) to determine the closure condition. The continuous treatment of convection, from dry thermals to deep precipitating convection, is achieved with the help of a continuous formulation of the entrainment-detrainment rates (depending on the convective vertical velocity) and of the CAPE relaxation time (depending on the convective over-turning time). The convective tendencies are directly expressed in terms of condensation and transport. Finally, the convective vertical velocity and condensates are fully prognostic, the latter being treated using the same microphysics scheme as for the resolved condensates but considering the convective environment. A Single Column Model (SCM) validation of this scheme is shown, allowing detailed comparisons with observed and explicitly simulated data. Four cases covering the convective spectrum are considered: over ocean, sensitivity to environmental moisture (S. Derbyshire) non precipitating shallow convection to deep precipitating convection, trade wind shallow convection (BOMEX) and strato-cumulus (FIRE), together with an entire continental diurnal cycle of convection (ARM). The emphasis is put on the characteristics of the scheme which enable a continuous treatment of convection. Then, a 3D LAM validation is presented considering an AMMA case with both observations and a CRM simulation using the same initial and lateral conditions as for the parameterized one. Finally, global

  19. Authentication Scheme Based on Principal Component Analysis for Satellite Images

    Directory of Open Access Journals (Sweden)

    Ashraf. K. Helmy

    2009-09-01

    Full Text Available This paper presents a multi-band wavelet image content authentication scheme for satellite images by incorporating the principal component analysis (PCA. The proposed schemeachieves higher perceptual transparency and stronger robustness. Specifically, the developed watermarking scheme can successfully resist common signal processing such as JPEG compression and geometric distortions such as cropping. In addition, the proposed scheme can be parameterized, thus resulting in more security. That is, an attacker may not be able to extract the embedded watermark if the attacker does not know the parameter.In an order to meet these requirements, the host image is transformed to YIQ to decrease the correlation between different bands, Then Multi-band Wavelet transform (M-WT is applied to each channel separately obtaining one approximate sub band and fifteen detail sub bands. PCA is then applied to the coefficients corresponding to the same spatial location in all detail sub bands. The last principle component band represents an excellent domain forinserting the water mark since it represents lowest correlated features in high frequency area of host image.One of the most important aspects of satellite images is spectral signature, the behavior of different features in different spectral bands, the results of proposed algorithm shows that the spectral stamp for different features doesn't tainted after inserting the watermark.

  20. Inverse Category Frequency based supervised term weighting scheme for text categorization

    CERN Document Server

    Wang, Deqing; Wu, Wenjun

    2010-01-01

    Unsupervised term weighting schemes, borrowed from information retrieval field, have been widely used for text categorization and the most famous one is tf.idf. The intuition behind idf seems less reasonable for TC task than IR task. In this paper, we introduce inverse category frequency into supervised term weighting schemes and propose a novel icf-based method. The method combines icf and relevance frequency (rf) to weight terms in training dataset. Our experiments have shown that icf-based supervised term weighting scheme is superior to tf.rf and prob-based supervised term weighting schemes and tf.idf based on two widely used datasets, i.e., the unbalanced Reuters-21578 corpus and the balanced 20 Newsgroup corpus. We also present the detailed evaluations of each category of the two datasets among the four term weighting schemes on precision, recall and F1 measure.

  1. Searchable attribute-based encryption scheme with attribute revocation in cloud storage.

    Science.gov (United States)

    Wang, Shangping; Zhao, Duqiao; Zhang, Yaling

    2017-01-01

    Attribute based encryption (ABE) is a good way to achieve flexible and secure access control to data, and attribute revocation is the extension of the attribute-based encryption, and the keyword search is an indispensable part for cloud storage. The combination of both has an important application in the cloud storage. In this paper, we construct a searchable attribute-based encryption scheme with attribute revocation in cloud storage, the keyword search in our scheme is attribute based with access control, when the search succeeds, the cloud server returns the corresponding cipher text to user and the user can decrypt the cipher text definitely. Besides, our scheme supports multiple keywords search, which makes the scheme more practical. Under the assumption of decisional bilinear Diffie-Hellman exponent (q-BDHE) and decisional Diffie-Hellman (DDH) in the selective security model, we prove that our scheme is secure.

  2. MPSK Symbol-based Soft-Information-Forwarding Scheme in Rayleigh Fading Channels

    Directory of Open Access Journals (Sweden)

    Huamei Xin

    2014-06-01

    Full Text Available In this paper, we proposed a symbol-based multiple phase shift keying (MPSK soft-information-forwarding (SIF scheme for a two-hop parallel relay wireless network in Rayleigh fading channel. First the binary information streams at the source are mapped into MPSK symbols, and the relays construct the relay processing function by passing the intermediate soft decisions. Then the relays broadcast the processed symbols to the destination. After the maximum ratio combination, the received symbols at the destination can be decided by maximum-likelihood (ML decision. Four MPSK symbol-based forwarding schemes are investigated and the simulation results show that the bit error rate (BER performance of soft information forwarding scheme has better BER performance than the existing memoryless forwarding scheme based on MPSK modulation, and it is more practical than the SIF scheme based on BPSK modulation

  3. Group key management scheme based on group signature with fault tolerance for mobile Ad hoc networks%适合移动Ad hoc网络基于群签名认证的弹性组密钥管理方案

    Institute of Scientific and Technical Information of China (English)

    朱昶胜; 刘鹏辉; 王庆荣; 曹来成

    2011-01-01

    针对移动Ad hoc网络中的安全组通信系统,提出了一个基于群签名认证的分布式组密钥管理方案.该方案利用门限密码技术并借鉴了PKI证书管理的第三方签名认证思想,在提高认证可信度的同时,极大地减少了密钥协商过程中所需的认证开销.分析表明,该方案具有良好的容错性;达到了第3级信任;能够抵抗网络中典型的主动和被动攻击;具备完美的前向和后向保密性;极大地降低了计算和通信开销.%According to the characteristics of group communication in mobile Ad hoc networks, this paper proposed a distributed key management scheme based on group signature authentication. By adopting the threshold cryptography and the method of third-party signature authentication,this scheme enhanced the authentication reliability and reduced largely the authentication cost in key agreement process greatly. The analysis shows this scheme is provably secure against the active and passive attacks with fault-torrance,achieves the trust level 3,has perfect forward and backward secrecy, and reduces the cost of computation and communication greatly.

  4. A sixth order hybrid finite difference scheme based on the minimized dispersion and controllable dissipation technique

    Science.gov (United States)

    Sun, Zhen-sheng; Luo, Lei; Ren, Yu-xin; Zhang, Shi-ying

    2014-08-01

    The dispersion and dissipation properties of a scheme are of great importance for the simulation of flow fields which involve a broad range of length scales. In order to improve the spectral properties of the finite difference scheme, the authors have previously proposed the idea of optimizing the dispersion and dissipation properties separately and a fourth order scheme based on the minimized dispersion and controllable dissipation (MDCD) technique is thus constructed [29]. In the present paper, we further investigate this technique and extend it to a sixth order finite difference scheme to solve the Euler and Navier-Stokes equations. The dispersion properties of the scheme is firstly optimized by minimizing an elaborately designed integrated error function. Then the dispersion-dissipation condition which is newly derived by Hu and Adams [30] is introduced to supply sufficient dissipation to damp the unresolved wavenumbers. Furthermore, the optimized scheme is blended with an optimized Weighted Essentially Non-Oscillation (WENO) scheme to make it possible for the discontinuity-capturing. In this process, the approximation-dispersion-relation (ADR) approach is employed to optimize the spectral properties of the nonlinear scheme to yield the true wave propagation behavior of the finite difference scheme. Several benchmark test problems, which include broadband fluctuations and strong shock waves, are solved to validate the high-resolution, the good discontinuity-capturing capability and the high-efficiency of the proposed scheme.

  5. Drinking Water Quality Criterion - Based site Selection of Aquifer Storage and Recovery Scheme in Chou-Shui River Alluvial Fan

    Science.gov (United States)

    Huang, H. E.; Liang, C. P.; Jang, C. S.; Chen, J. S.

    2015-12-01

    Land subsidence due to groundwater exploitation is an urgent environmental problem in Choushui river alluvial fan in Taiwan. Aquifer storage and recovery (ASR), where excess surface water is injected into subsurface aquifers for later recovery, is one promising strategy for managing surplus water and may overcome water shortages. The performance of an ASR scheme is generally evaluated in terms of recovery efficiency, which is defined as percentage of water injected in to a system in an ASR site that fulfills the targeted water quality criterion. Site selection of an ASR scheme typically faces great challenges, due to the spatial variability of groundwater quality and hydrogeological condition. This study proposes a novel method for the ASR site selection based on drinking quality criterion. Simplified groundwater flow and contaminant transport model spatial distributions of the recovery efficiency with the help of the groundwater quality, hydrological condition, ASR operation. The results of this study may provide government administrator for establishing reliable ASR scheme.

  6. Admission Control Scheme for Multi-class Services in QoS-based Mobile Cellular Networks

    Institute of Scientific and Technical Information of China (English)

    YINZhiming; XIEJianying

    2004-01-01

    Call admission control (CAC) is one of the key schemes to guarantee Quality of service (QoS) in mobile cellular networks. In this paper, we propose an optimal CAC scheme based on Semi-Markov decision processes (SMDP) theory to support multi-class services for QoS wireless networks. Linear programming formulation is used to find the optimal solution, which maximizes the channel utilization while meeting the requirements of QoS constraints. The numerical results show that the performance of our scheme outperforms DCAC scheme.

  7. Cryptanalysis on AW digital signature scheme based on error-correcting codes

    Institute of Scientific and Technical Information of China (English)

    张振峰; 冯登国; 戴宗锋

    2002-01-01

    In 1993, Alabhadi and Wicker gave a modification to Xinmei Digital Signature Scheme based on error-correcting codes, which is usually denoted by AW Scheme. In this paper we show that the AW Scheme is actually not secure: anyone holding public keys of the signatory can obtain the equivalent private keys, and then forge digital signatures for arbitrary messages successfully. We also point out that one can hardly construct a digital signature scheme with high-level security due to the difficulty of decomposing large matrixes.

  8. MULTIMEDIA DATA TRANSMISSION THROUGH TCP/IP USING HASH BASED FEC WITH AUTO-XOR SCHEME

    Directory of Open Access Journals (Sweden)

    R. Shalin

    2012-09-01

    Full Text Available The most preferred mode for communication of multimedia data is through the TCP/IP protocol. But on the other hand the TCP/IP protocol produces huge packet loss unavoidable due to network traffic and congestion. In order to provide a efficient communication it is necessary to recover the loss of packets. The proposed scheme implements Hash based FEC with auto XOR scheme for this purpose. The scheme is implemented through Forward error correction, MD5 and XOR for providing efficient transmission of multimedia data. The proposed scheme provides transmission high accuracy, throughput and low latency and loss.

  9. A novel scheme based on minimum delay at the edges for optical burst switching networks

    Institute of Scientific and Technical Information of China (English)

    Jinhui Yu(于金辉); Yijun Yang(杨毅军); Yuehua Chen(陈月华); Ge Fan(范戈)

    2003-01-01

    This paper proposes a novel scheme based on minimum delay at the edges (MDE) for optical burst switching(OBS) networks. This scheme is designed to overcome the long delay at the edge nodes of OBS networks.The MDE scheme features simultaneous burst assembly, channel scheduling, and pre-transmission of controlpacket. It also features estimated setup and explicit release (ESXR) signaling protocol. The MDE schemecan minimize the delay at the edge nodes for data packets, and improve the end-to-end latency performancefor OBS networks. In addition, comparing with the conventional scheme, the performances of the MDEscheme are analyzed in this paper.

  10. An efficient authentication scheme based on one-way key chain for sensor network

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    To strike a tradeoff between the security and the consumption of energy, computing and communication resources in the nodes, this paper presents an efficient authentication scheme based on one-way key chain for sensor network. The scheme can provide immediate authentication to fulfill the latency and the storage requirements and defends against various attacks such as replay, impersonation and denial of service. Meanwhile,our scheme possesses low overhead and scalability to large networks. Furthermore, the simple related protocols or algorithms in the scheme and inexpensive public-key operation required in view of resource-starved sensor nodes minimize the storage, computation and communication overhead, and improve the efficiency of our scheme. In addition, the proposed scheme also supports source authentication without precluding in-network processing and passive participation.

  11. Evaluation of Scheme Design of Blast Furnace Based on Artificial Neural Network

    Institute of Scientific and Technical Information of China (English)

    TANG Hong; LI Jing-min; YAO Bi-qiang; LIAO Hong-fu; YAO Jin

    2008-01-01

    Blast furnace scheme design is very important, since it directly affects the performance, cost and configuration of the blast furnace. An evaluation approach to furnace scheme design was brought forward based on artificial neural network. Ten independent parameters which determined a scheme design were proposed. The improved threelayer BP network algorithm was used to build the evaluation model in which the 10 independent parameters were taken as input evaluation indexes and the degree to which the scheme design satisfies the requirements of the blast furnace as output. It was trained by the existing samples of the scheme design and the experts' experience, and then tested by the other samples so as to develop the evaluation model. As an example, it is found that a good scheme design of blast furnace can be chosen by using the evaluation model proposed.

  12. A Novel Digital Certificate Based Remote Data Access Control Scheme in WSN

    Directory of Open Access Journals (Sweden)

    Wei Liang

    2015-01-01

    Full Text Available A digital certificate based remote data access control scheme is proposed for safe authentication of accessor in wireless sensor network (WSN. The scheme is founded on the access control scheme on the basis of characteristic expression (named CEB scheme. Data is divided by characteristics and the key for encryption is related to characteristic expression. Only the key matching with characteristic expression can decrypt the data. Meanwhile, three distributed certificate detection methods are designed to prevent the certificate from being misappropriated by hostile anonymous users. When a user starts query, the key access control method can judge whether the query is valid. In this case, the scheme can achieve public certificate of users and effectively protect query privacy as well. The security analysis and experiments show that the proposed scheme is superior in communication overhead, storage overhead, and detection probability.

  13. Improvement of Identity-Based Threshold Proxy Signature Scheme with Known Signers

    Institute of Scientific and Technical Information of China (English)

    LI Fagen; HU Yupu; CHEN Jie

    2006-01-01

    In 2006, Bao et al proposed an identity-based threshold proxy signature scheme with known signers. In this paper, we show that Bao et al 's scheme is vulnerable to the forgery attack. An adversary can forge a valid threshold proxy signature for any message with knowing a previously valid threshold proxy signature. In addition, their scheme also suffers from the weakness that the proxy signers might change the threshold value. That is, the proxy signers can arbitrarily modify the threshold strategy without being detected by the original signer or verifiers, which might violate the original signer's intent. Furthermore, we propose an improved scheme that remedies the weaknesses of Bao et al 's scheme. The improved scheme satisfies all secure requirements for threshold proxy signature.

  14. A User Authentication Scheme Based on Elliptic Curves Cryptography for Wireless Ad Hoc Networks.

    Science.gov (United States)

    Chen, Huifang; Ge, Linlin; Xie, Lei

    2015-07-14

    The feature of non-infrastructure support in a wireless ad hoc network (WANET) makes it suffer from various attacks. Moreover, user authentication is the first safety barrier in a network. A mutual trust is achieved by a protocol which enables communicating parties to authenticate each other at the same time and to exchange session keys. For the resource-constrained WANET, an efficient and lightweight user authentication scheme is necessary. In this paper, we propose a user authentication scheme based on the self-certified public key system and elliptic curves cryptography for a WANET. Using the proposed scheme, an efficient two-way user authentication and secure session key agreement can be achieved. Security analysis shows that our proposed scheme is resilient to common known attacks. In addition, the performance analysis shows that our proposed scheme performs similar or better compared with some existing user authentication schemes.

  15. Comment Fail-Stop Blind Signature Scheme Design Based on Pairings

    Institute of Scientific and Technical Information of China (English)

    HU Xiaoming; HUANG Shangteng

    2006-01-01

    Fail-stop signature schemes provide security for a signer against forgeries of an enemy with unlimited computational power by enabling the signer to provide a proof of forgery when a forgery happens. Chang et al proposed a robust fail-stop blind signature scheme based on bilinear pairings. However, in this paper, it will be found that there are several mistakes in Chang et al' fail-stop blind signature scheme. Moreover, it will be pointed out that this scheme doesn' meet the property of a fail-stop signature: unconditionally secure for a signer. In Chang et al' scheme, a forger can forge a valid signature that can' be proved by a signer using the "proof of forgery". The scheme also doesn' possess the unlinkability property of a blind signature.

  16. An Efficient Novel Key Management Scheme for Enhancing User Authentication in A WSN

    Directory of Open Access Journals (Sweden)

    Harjot Bawa

    2013-01-01

    Full Text Available The Wireless Sensor Networks are energy constrained and are normally low cost and low power devices. These nodes are deployed over a specific area for specific goals. Due to energy and memory constraints, secure communication among these sensors is challenging management issue. In order to ensure security, proper connectivity among nodes and resilience against node capture, we propose a scheme called as Random Pre-Key distribution scheme which takes advantage of the binomial key pattern while creating and distributing keys. The value of keys would develop the number of patterns, which is given by the binomial distribution, which would be helpful in maintaining a key pool which is all though random in nature and following a pattern leads to more probability of network connection links. This paper provides a secured communication in WSNs environment and pairing user authentication has been proposed. We employ the idea of dividing the sensor network field into scattered nodes. Inside the scenario, one of the sensor nodes is selected as a server sensor node which is responsible for delivering the key. The novelty of the proposed scenario lies behind the idea of incorporating the sensor nodes along with the proper user authentications. We calculate the throughput involving a periodic traffic and obtained results from the xgraph utility with the use of Network Simulator. The results of this key scheme are obtained and show that improvement in terms of connectivity.

  17. Adaptive multi-objective Optimization scheme for cognitive radio resource management

    KAUST Repository

    Alqerm, Ismail

    2014-12-01

    Cognitive Radio is an intelligent Software Defined Radio that is capable to alter its transmission parameters according to predefined objectives and wireless environment conditions. Cognitive engine is the actuator that performs radio parameters configuration by exploiting optimization and machine learning techniques. In this paper, we propose an Adaptive Multi-objective Optimization Scheme (AMOS) for cognitive radio resource management to improve spectrum operation and network performance. The optimization relies on adapting radio transmission parameters to environment conditions using constrained optimization modeling called fitness functions in an iterative manner. These functions include minimizing power consumption, Bit Error Rate, delay and interference. On the other hand, maximizing throughput and spectral efficiency. Cross-layer optimization is exploited to access environmental parameters from all TCP/IP stack layers. AMOS uses adaptive Genetic Algorithm in terms of its parameters and objective weights as the vehicle of optimization. The proposed scheme has demonstrated quick response and efficiency in three different scenarios compared to other schemes. In addition, it shows its capability to optimize the performance of TCP/IP layers as whole not only the physical layer.

  18. A Statistically-Hiding Integer Commitment Scheme Based on Groups with Hidden Order

    DEFF Research Database (Denmark)

    Damgård, Ivan Bjerre; Fujisaki, Eiichiro

    2002-01-01

    of the contents of commitments and for verifying multiplicative relations over the integers on committed values. The scheme can be seen as a generalization, with a slight modification, of the earlier scheme of Fujisaki and Okamoto [14]. The reasons we revisit the earlier scheme and give some modification...... the possibility that a prover manages to produce a common input on which he can cheat easily. This means that the standard definition of proofs of knowledge cannot be satisfied. Therefore we introduce a new definition for computationally convincing proofs of knowledge, designed to handle the case where the common...

  19. Efficient Dynamic Threshold Group Signature Scheme Based on Elliptic Curve Cryptosystem

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The short secret key characteristic of elliptic curve cryptosystem (ECC) are integrated with the (t,n ) threshold method to create a practical threshold group signature scheme characterized by simultaneous signing. The scheme not only meets the requirements of anonymity and traceability of group signature but also can withstand Tseng and Wangs conspiracy attack. It allows the group manager to add new members and delete old members according to actual application, while the system parameters have a little change. Cryptanalysis result shows that the scheme is efficient and secure.

  20. Development of an estuarine assessment scheme for the management of a highly urbanised catchment/estuary system, Sydney estuary, Australia.

    Science.gov (United States)

    Birch, G F; Gunns, T J; Chapman, D; Harrison, D

    2016-05-01

    As coastal populations increase, considerable pressures are exerted on estuarine environments. Recently, there has been a trend towards the development and use of estuarine assessment schemes as a decision support tool in the management of these environments. These schemes offer a method by which complex environmental data is converted into a readily understandable and communicable format for informed decision making and effective distribution of limited management resources. Reliability and effectiveness of these schemes are often limited due to a complex assessment framework, poor data management and use of ineffective environmental indicators. The current scheme aims to improve reliability in the reporting of estuarine condition by including a concise assessment framework, employing high-value indicators and, in a unique approach, employing fuzzy logic in indicator evaluation. Using Sydney estuary as a case study, each of the 15 sub-catchment/sub-estuary systems were assessed using the current scheme. Results identified that poor sediment quality was a significant issue in Blackwattle/Rozelle Bay, Iron Cove and Hen and Chicken Bay while poor water quality was of particular concern in Duck River, Homebush Bay and the Parramatta River. Overall results of the assessment scheme were used to prioritise the management of each sub-catchment/sub-estuary assessed with Blackwattle/Rozelle Bay, Homebush Bay, Iron Cove and Duck River considered to be in need of a high priority management response. A report card format, using letter grades, was employed to convey the results of the assessment in a readily understood manner to estuarine managers and members of the public. Letter grades also provide benchmarking and performance monitoring ability, allowing estuarine managers to set improvement targets and assesses the effectiveness of management strategies. The current assessment scheme provides an effective, integrated and consistent assessment of estuarine health and

  1. Improving Biometric-Based Authentication Schemes with Smart Card Revocation/Reissue for Wireless Sensor Networks

    Science.gov (United States)

    Moon, Jongho; Lee, Donghoon; Lee, Youngsook; Won, Dongho

    2017-01-01

    User authentication in wireless sensor networks is more difficult than in traditional networks owing to sensor network characteristics such as unreliable communication, limited resources, and unattended operation. For these reasons, various authentication schemes have been proposed to provide secure and efficient communication. In 2016, Park et al. proposed a secure biometric-based authentication scheme with smart card revocation/reissue for wireless sensor networks. However, we found that their scheme was still insecure against impersonation attack, and had a problem in the smart card revocation/reissue phase. In this paper, we show how an adversary can impersonate a legitimate user or sensor node, illegal smart card revocation/reissue and prove that Park et al.’s scheme fails to provide revocation/reissue. In addition, we propose an enhanced scheme that provides efficiency, as well as anonymity and security. Finally, we provide security and performance analysis between previous schemes and the proposed scheme, and provide formal analysis based on the random oracle model. The results prove that the proposed scheme can solve the weaknesses of impersonation attack and other security flaws in the security analysis section. Furthermore, performance analysis shows that the computational cost is lower than the previous scheme. PMID:28441331

  2. Efficient hierarchical identity based encryption scheme in the standard model over lattices

    Institute of Scientific and Technical Information of China (English)

    Feng-he WANG; Chun-xiao WANG; Zhen-hua LIU

    2016-01-01

    Using lattice basis delegation in a fi xed dimension, we propose an efficient lattice-based hierarchical identity based encryption (HIBE) scheme in the standard model whose public key size is only (dm2+mn) log q bits and whose message-ciphertext expansion factor is only log q, where d is the maximum hierarchical depth and (n,m,q) are public parameters. In our construction, a novel public key assignment rule is used to averagely assign one random and public matrix to two identity bits, which implies that d random public matrices are enough to build the proposed HIBE scheme in the standard model, compared with the case in which 2d such public matrices are needed in the scheme proposed at Crypto 2010 whose public key size is (2dm2+mn+m) log q. To reduce the message-ciphertext expansion factor of the proposed scheme to log q, the encryption algorithm of this scheme is built based on Gentry’s encryption scheme, by which m2 bits of plaintext are encrypted into m2 log q bits of ciphertext by a one time encryption operation. Hence, the presented scheme has some advantages with respect to not only the public key size but also the message-ciphertext expansion factor. Based on the hardness of the learning with errors problem, we demonstrate that the scheme is secure under selective identity and chosen plaintext attacks.

  3. An implicit evolution scheme for active contours and surfaces based on IIR filtering.

    Science.gov (United States)

    Delibasis, Konstantinos K; Asvestas, Pantelis A; Kechriniotis, Aristides I; Matsopoulos, George K

    2014-05-01

    In this work, we present an approach for implementing an implicit scheme for the numerical solution of the partial differential equation of the evolution of an active contour/surface. The proposed scheme is applicable to any variant of the traditional active contour (AC), irrespectively of the calculation of the image-based force field and it is readily applicable to explicitly parameterized active surfaces (AS). The proposed approach is formulated as an infinite impulse response (IIR) filtering of the coordinates of the contour/surface points. The poles of the filter are determined by the parameters controlling the shape of the active contour/surface. We show that the proposed IIR-based implicit evolution scheme has very low complexity. Furthermore, the proposed scheme is numerically stable, thus it allows the convergence of the AC/AS with significantly fewer iterations than the explicit evolution scheme. It also possesses the separability property along the two parameters of the AS, thus it may be applied to deformable surfaces, without the need to store and invert large sparse matrices. We implemented the proposed IIR-based implicit evolution scheme in the Vector Field Convolution (VFC) AC/AS using synthetic and clinical volumetric data. We compared the segmentation results with those of the explicit AC/AS evolution, in terms of accuracy and efficiency. Results show that the VFC AC/AS with the proposed IIR-based implicit evolution scheme achieves the same segmentation results with the explicit scheme, with considerably less computation time.

  4. Dropping out of Ethiopia’s Community Based Health Insurance scheme

    NARCIS (Netherlands)

    A.D. Mebratie (Anagaw); R.A. Sparrow (Robert); Z.Y. Debebe (Zelalem); G. Alemu (Getnet ); A.S. Bedi (Arjun Singh)

    2014-01-01

    textabstractLow contract renewal rates have been identified as one of the challenges facing the development of community based health insurance schemes (CBHI). This paper uses longitudinal household survey data to examine dropout in the case of Ethiopia’s pilot CBHI scheme, which saw enrolment incre

  5. Design Principles for Secure Wireless Sensor Networks: Key Management Schemes and Malicious Attacks

    Science.gov (United States)

    2010-09-09

    focus in the first period (August 2006 through July 2007) was 1. to de- velop a new key pre-distribution method based on symmetric polynomials (which we...secure sensor net- work, in which sensor devices may also employ periodic sleep -active duty-cycling to conserve precious energy. We provided a...MKPS: A Multivariate Polynomial Scheme for Symmetric Key-Establishment in Distributed Sensor Networks,” in Proc. ACM Inter- national Wireless

  6. Scheme of adaptive polarization filtering based on Kalman model

    Institute of Scientific and Technical Information of China (English)

    Song Lizhong; Qi Haiming; Qiao Xiaolin; Meng Xiande

    2006-01-01

    A new kind of adaptive polarization filtering algorithm in order to suppress the angle cheating interference for the active guidance radar is presented. The polarization characteristic of the interference is dynamically tracked by using Kalman estimator under variable environments with time. The polarization filter parameters are designed according to the polarization characteristic of the interference, and the polarization filtering is finished in the target cell. The system scheme of adaptive polarization filter is studied and the tracking performance of polarization filter and improvement of angle measurement precision are simulated. The research results demonstrate this technology can effectively suppress the angle cheating interference in guidance radar and is feasible in engineering.

  7. Remodulation scheme based on a two-section reflective SOA

    Science.gov (United States)

    Guiying, Jiang; Lirong, Huang

    2014-05-01

    A simple and cost-effective remodulation scheme using a two-section reflective semiconductor optical amplifier (RSOA) is proposed for a colorless optical network unit (ONU). Under proper injection currents, the front section functions as a modulator to upload the upstream signal while the rear section serves as a data eraser for efficient suppression of the downstream data. The dependences of the upstream transmission performance on the lengths and driven currents of the RSOA, the injection optical power and extinction ratio of the downstream are investigated. By optimizing these parameters, the downstream data can be more completely suppressed and the upstream transmission performance can be greatly improved.

  8. Virtual Reality-based Telesurgery via Teleprogramming Scheme Combined with Semi-autonomous Control.

    Science.gov (United States)

    Zhijiang, Du; Zhiheng, Jia; Minxiu, Kong

    2005-01-01

    Telesurgery systems have long been suffering variable and unpredictable Internet commutation time delay, operation fatigue, and other drawbacks. Based on virtual reality technology, a teleprogramming scheme combined with semi-autonomous control is introduced to guarantee the robustness and efficiency of teleoperation of HIT-RAOS, a robot-assisted orthopedic surgery system. In this system, without considering time delay, the operator can just interact with virtual environment which provides real-time 3D vision, stereophonic sound, and tactile and force feedback imitated by a parallel master manipulator. And several tasks can be managed simultaneously via semi-autonomous control. Finally, the method is experimentally demonstrated on an experiment of locking of intramedullary nails, and is shown to effectively provide stability and performances.

  9. NATURAL RESOURCE MANAGEMENT IN THE SIERRA OF SONORA UNDER THE SCHEME UMAFOR. CASE STUDY: SIERRA ALTA AND SIERRA LA MADERA

    Directory of Open Access Journals (Sweden)

    Hugo Silva-Kurumiya

    2011-05-01

    Full Text Available This paper shows the use and value of natural resources from a social, sustainable and legal perspective, under the scheme of Sustainable Forest Management Units (UMAFOR by its Spanish acronym. Two participatory workshops were carried out in March 2010, one in UMAFOR Sierra La Madera and another in UMAFOR Sierra Alta, belonging to the Sierra de Sonora. An adaptation of “Problems, Causes and Consequences” of Ramírez-García (2004 methodology was used to discuss issues such as conservation, productive activities, society, laws, research and support programs. The objective was to analyze challenges and opportunities in the Sierra de Sonora under this management scheme. The ratting of natural resource for inhabitant and producers was documented based in ecosystems type and its value for use. Economic value was the most important for productive and non productive use; however, there are opportunities to transit from traditional to sustainable activities. Local producers are interested in linking whit research centers and consultants to get support for diversification of productive activities. It is possible to have changes according to sustainable development; UMAFOR is an alternative to achieve those changes.

  10. Water management for controlling the breeding of Anopheles mosquitoes in rice irrigation schemes in Kenya

    DEFF Research Database (Denmark)

    Mutero, C M; Blank, H; Konradsen, F

    2000-01-01

    between the 4th and 1st instar larvae in the subplots was only 0.08, indicating very low survival rates. In contrast, the 4th/1st instar ratio for subplots with other water management regimes ranged between 0.27 and 0.68, suggesting a correspondingly higher survival than observed with intermittent...... differences among subplots with different water regimes. The average yield per hectare ranged from 4.8-5.3 metric tonnes. The average daily water percolation/seepage rate was 3.6 mm and did not significantly differ among different water management regimes. Further research is necessary to, among other things......An experiment to assess the impact of intermittent irrigation on Anopheles larval populations, rice yields and water use was conducted in the Mwea rice irrigation scheme in Kenya. Four water regimes including intermittent irrigation were tested in a complete randomized block experimental design...

  11. Comparison of Aircraft Models and Integration Schemes for Interval Management in the TRACON

    Science.gov (United States)

    Neogi, Natasha; Hagen, George E.; Herencia-Zapana, Heber

    2012-01-01

    Reusable models of common elements for communication, computation, decision and control in air traffic management are necessary in order to enable simulation, analysis and assurance of emergent properties, such as safety and stability, for a given operational concept. Uncertainties due to faults, such as dropped messages, along with non-linearities and sensor noise are an integral part of these models, and impact emergent system behavior. Flight control algorithms designed using a linearized version of the flight mechanics will exhibit error due to model uncertainty, and may not be stable outside a neighborhood of the given point of linearization. Moreover, the communication mechanism by which the sensed state of an aircraft is fed back to a flight control system (such as an ADS-B message) impacts the overall system behavior; both due to sensor noise as well as dropped messages (vacant samples). Additionally simulation of the flight controller system can exhibit further numerical instability, due to selection of the integration scheme and approximations made in the flight dynamics. We examine the theoretical and numerical stability of a speed controller under the Euler and Runge-Kutta schemes of integration, for the Maintain phase for a Mid-Term (2035-2045) Interval Management (IM) Operational Concept for descent and landing operations. We model uncertainties in communication due to missed ADS-B messages by vacant samples in the integration schemes, and compare the emergent behavior of the system, in terms of stability, via the boundedness of the final system state. Any bound on the errors incurred by these uncertainties will play an essential part in a composable assurance argument required for real-time, flight-deck guidance and control systems,. Thus, we believe that the creation of reusable models, which possess property guarantees, such as safety and stability, is an innovative and essential requirement to assessing the emergent properties of novel airspace

  12. A transmon-based quantum half-adder scheme

    Science.gov (United States)

    Chatterjee, Dibyendu; Roy, Arijit

    2015-09-01

    A four-level qubit system is applied to realize quantum half-adder operation. The half-adder circuit is obtained in terms of a quantum CPHASE gate realized by the qubits comprised of four energy levels [C. P. Yang, Prog. Theor. Phys. 128, 587 (2012)], and such a CPHASE gate is demonstrated using the transmon. Commonly, higher energy levels are very sensitive and are easily perturbed by the noise sources. Compared to other qubit systems, the higher energy levels of the transmon are less prone to noise such as charge noise, flux noise and other noises. Further, the order of the dephasing time of the higher energy levels (third and fourth energy levels) is nearly the same as that of the lower energy levels of the transmon when the ratio between the Josephson energy and the charging energy ≫ 1. A system of three transmons coupled to a single high quality-factor superconducting coplanar resonator is demonstrated to obtain two- and three-qubit CPHASE gates which are in turn used to obtain the quantum half-adder operation. The main advantage of this quantum half-adder scheme is the reduction in the number of required elementary gates, leading to a significant increase in operational speed and robustness compared to the other existing half-adder schemes. The operational time of a complete half-adder operation is ˜ 37 ns. The methods presented in this article can also be implemented for more complicated quantum circuits.

  13. System for Anonymous Data Collection Based on Group Signature Scheme

    Directory of Open Access Journals (Sweden)

    David Troják

    2016-01-01

    Full Text Available This paper deals with an anonymous data collection in the Internet of Things (IoT. the privacy and anonymity of the data source is important for many IoT applications, such as in agriculture, health, and automotive. the proposed data‑collection system provides anonymity for the data sources by applying a cooperation group scheme. the group scheme also provides a low power consumption. the system is built upon the Tor (The Onion Router anonymous network, which is a part of the Internet darknet. the proposed system was designed for the Android devices on the client side and for Java environment on the server side. We evaluated the anonymous data collection in a real‑use scenario that covers selected data acquisition (e.g. signal strength from smartphones triggered by their geographical location change. the results show that the proposed system provides the sufficient data source anonymity, an effective revocation, a low computational cost and a low overhead.

  14. Designing Pay-As-You-Throw schemes in municipal waste management services: A holistic approach

    Energy Technology Data Exchange (ETDEWEB)

    Elia, Valerio; Gnoni, Maria Grazia, E-mail: mariagrazia.gnoni@unisalento.it; Tornese, Fabiana

    2015-10-15

    Highlights: • Pay-As-You-Throw (PAYT) schemes are becoming widespread in several countries. • Economic, organizational and technological issues have to be integrated in an efficient PAYT model design. • Efficiency refers to a PAYT system which support high citizen participation rates as well as economic sustainability. • Different steps and constraints have to be evaluated from collection services to type technologies. • An holistic approach is discussed to support PAYT systems diffusion. - Abstract: Pay-As-You-Throw (PAYT) strategies are becoming widely applied in solid waste management systems; the main purpose is to support a more sustainable – from economic, environmental and social points of view – management of waste flows. Adopting PAYT charging models increases the complexity level of the waste management service as new organizational issues have to be evaluated compared to flat charging models. In addition, innovative technological solutions could also be adopted to increase the overall efficiency of the service. Unit pricing, user identification and waste measurement represent the three most important processes to be defined in a PAYT system. The paper proposes a holistic framework to support an effective design and management process. The framework defines most critical processes and effective organizational and technological solutions for supporting waste managers as well as researchers.

  15. Review of nuclear waste management schemes in Eastern European countries by CASSIOPEE

    Energy Technology Data Exchange (ETDEWEB)

    Lempert, J.P. [DBE, Peine (Germany)

    1994-12-31

    The European Union launched two important assistance programme Phare and TACIS. Within these programmes the subject of Nuclear Waste Management in Eastern European Countries and in CIS is being investigated by CASSIOPEE. Six national radioactive waste management agencies existing the CEU member states have founded the European Economic Interest Grouping CASSIOPEE. The grouping aims at providing the Eastern European Countries and the CIS within assistance in developing their radioactive waste management system by transferring its experience and expertise. As a first task, the grouping was charged by the EU at Brussels with performing {open_quotes}A Detailed Regional Study of Management Schemes for the Back-end of the Nuclear Fuel Cycle, Radioactive Waste Management and the Decommissioning of Obsolete Nuclear Installations{close_quotes}. During phase A several problem areas have been identified in different countries. The outcome of phase B will include distinct recommendations for improvements to facilities, systems and procedures, as well as recommendations for later specific studies, including a preliminary definition of their subject and scope.

  16. An Efficient Code-Based Threshold Ring Signature Scheme with a Leader-Participant Model

    Directory of Open Access Journals (Sweden)

    Guomin Zhou

    2017-01-01

    Full Text Available Digital signature schemes with additional properties have broad applications, such as in protecting the identity of signers allowing a signer to anonymously sign a message in a group of signers (also known as a ring. While these number-theoretic problems are still secure at the time of this research, the situation could change with advances in quantum computing. There is a pressing need to design PKC schemes that are secure against quantum attacks. In this paper, we propose a novel code-based threshold ring signature scheme with a leader-participant model. A leader is appointed, who chooses some shared parameters for other signers to participate in the signing process. This leader-participant model enhances the performance because every participant including the leader could execute the decoding algorithm (as a part of signing process upon receiving the shared parameters from the leader. The time complexity of our scheme is close to Courtois et al.’s (2001 scheme. The latter is often used as a basis to construct other types of code-based signature schemes. Moreover, as a threshold ring signature scheme, our scheme is as efficient as the normal code-based ring signature.

  17. Implementation of an energy-efficient scheduling scheme based on pipeline flux leak monitoring networks

    Institute of Scientific and Technical Information of China (English)

    ZHOU Peng; YAO JiangHe; PEI JiuLing

    2009-01-01

    Flow against pipeline leakage and the pipe network sudden burst pipe to pipeline leakage flow for the application objects,an energy-efficient real-time scheduling scheme is designed extensively used in pipeline leak monitoring.The proposed scheme can adaptively adjust the network rate in real-time and reduce the cell loss rate,so that it can efficiently avoid the traffic congestion.The recent evolution of wireless sensor networks has yielded a demand to improve energy-efficient scheduling algorithms and energy-efficient medium access protocols.This paper proposes an energy-efficient real-time scheduling scheme that reduces power consumption and network errors on pipeline flux leak monitoring networks.The proposed scheme is based on a dynamic modulation scaling scheme which can scale the number of bits per symbol and a switching scheme which can swap the polling schedule between channels.Built on top of EDF scheduling policy,the proposed scheme enhances the power performance without violating the constraints of real-time streams.The simulation results show that the proposed scheme enhances fault-tolerance and reduces power consumption.Furthermore,that Network congestion avoidance strategy with an energy-efficient real-time scheduling scheme can efficiently improve the bandwidth utilization,TCP friendliness and reduce the packet drop rate in pipeline flux leak monitoring networks.

  18. Cryptanalysis and Performance Evaluation of Enhanced Threshold Proxy Signature Scheme Based on RSA for Known Signers

    Directory of Open Access Journals (Sweden)

    Raman Kumar

    2013-01-01

    Full Text Available In these days there are plenty of signature schemes such as the threshold proxy signature scheme (Kumar and Verma 2010. The network is a shared medium so that the weakness security attacks such as eavesdropping, replay attack, and modification attack. Thus, we have to establish a common key for encrypting/decrypting our communications over an insecure network. In this scheme, a threshold proxy signature scheme based on RSA, any or more proxy signers can cooperatively generate a proxy signature while or fewer of them cannot do it. The threshold proxy signature scheme uses the RSA cryptosystem to generate the private and the public key of the signers (Rivest et al., 1978. Comparison is done on the basis of time complexity, space complexity, and communication overhead. We compare the performance of four schemes (Hwang et al. (2003, Kuo and Chen (2005, Yong-Jun et al. (2007, and Li et al. (2007, with the performance of a scheme that has been proposed earlier by the authors of this paper. In the proposed scheme, both the combiner and the secret share holder can verify the correctness of the information that they are receiving from each other. Therefore, the enhanced threshold proxy signature scheme is secure and efficient against notorious conspiracy attacks.

  19. Security enhancement of a biometric based authentication scheme for telecare medicine information systems with nonce.

    Science.gov (United States)

    Mishra, Dheerendra; Mukhopadhyay, Sourav; Kumari, Saru; Khan, Muhammad Khurram; Chaturvedi, Ankita

    2014-05-01

    Telecare medicine information systems (TMIS) present the platform to deliver clinical service door to door. The technological advances in mobile computing are enhancing the quality of healthcare and a user can access these services using its mobile device. However, user and Telecare system communicate via public channels in these online services which increase the security risk. Therefore, it is required to ensure that only authorized user is accessing the system and user is interacting with the correct system. The mutual authentication provides the way to achieve this. Although existing schemes are either vulnerable to attacks or they have higher computational cost while an scalable authentication scheme for mobile devices should be secure and efficient. Recently, Awasthi and Srivastava presented a biometric based authentication scheme for TMIS with nonce. Their scheme only requires the computation of the hash and XOR functions.pagebreak Thus, this scheme fits for TMIS. However, we observe that Awasthi and Srivastava's scheme does not achieve efficient password change phase. Moreover, their scheme does not resist off-line password guessing attack. Further, we propose an improvement of Awasthi and Srivastava's scheme with the aim to remove the drawbacks of their scheme.

  20. Efficient enhancing scheme for TCP performance over satellite-based internet

    Institute of Scientific and Technical Information of China (English)

    Wang Lina; Gu Xuemai

    2007-01-01

    Satellite link characteristics drastically degrade transport control protocol (TCP) performance. An efficient performance enhancing scheme is proposed. The improvement of TCP performance over satellite-based Intemet is accomplished by protocol transition gateways at each end ora satellite link. The protocol which runs over a satellite link executes the receiver-driven flow control and acknowledgements- and timeouts-based error control strategies. The validity of this TCP performance enhancing scheme is verified by a series of simulation experiments. Results show that the proposed scheme can efficiently enhance the TCP performance over satellite-based Intemet and ensure that the available bandwidth resources of the satellite link are fully utilized.

  1. Pairing-Free ID-Based Key-Insulated Signature Scheme

    Institute of Scientific and Technical Information of China (English)

    Guo-Bin Zhu; Hu Xiong; Zhi-Guang Qin

    2015-01-01

    Abstract⎯Without the assumption that the private keys are kept secure perfectly, cryptographic primitives cannot be deployed in the insecure environments where the key leakage is inevitable. In order to reduce the damage caused by the key exposure in the identity-based (ID-based) signature scenarios efficiently, we propose an ID-based key-insulated signature scheme in this paper, which eliminates the expensive bilinear pairing operations. Compared with the previous work, our scheme minimizes the computation cost without any extra cost. Under the discrete logarithm (DL) assumption, a security proof of our scheme in the random oracle model has also been given.

  2. An Effective Capacity Estimation Scheme in IEEE802.11-based Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    H. Zafar

    2012-11-01

    Full Text Available Capacity estimation is a key component of any admission control scheme required to support quality of serviceprovision in mobile ad hoc networks. A range of schemes have been previously proposed to estimate residualcapacity that is derived from window-based measurements of channel estimation. In this paper a simple and improvedmechanism to estimate residual capacity in IEEE802.11-based ad hoc networks is presented. The scheme proposesthe use of a ‘forgiveness’ factor to weight these previous measurements and is shown through simulation-basedevaluation to provide accurate utilizations estimation and improved residual capacity based admission control.

  3. A Fair Off-Line Electronic Cash Scheme Based on Restrictive Partially Blind Signature

    Institute of Scientific and Technical Information of China (English)

    王常吉; 吴建平; 段海新

    2004-01-01

    A fair off-line electronic cash scheme was presented based on a provable secure restrictive partially blind signature.The scheme is more efficient than those of previous works as the expiry date and denomination information are embedded in the electronic cash,which alleviates the storage pressure for the bank to check double spending,and the bank need not use different public keys for different coin values,shops and users need not carry a list of bank's public keys to verify in their electronic wallet.The modular exponentiations are reduced for both the user and the bank by letting the trustee publish the public values with different structure as those of previous electronic cash schemes.The scheme security is based on the random oracle model and the decision Diffie-Hellman assumption.The scheme can be easily extended to multi-trustees and multi-banks using threshold cryptography.

  4. A kind of signature scheme based on class groups of quadratic fields

    Institute of Scientific and Technical Information of China (English)

    董晓蕾; 曹珍富

    2004-01-01

    Quadratic-field cryptosystem is a cryptosystem built from discrete logarithm problem in ideal class groups of quadratic fields(CL-DLP). The problem on digital signature scheme based on ideal class groups of quadratic fields remained open, because of the difficulty of computing class numbers of quadratic fields. In this paper, according to our researches on quadratic fields, we construct the first digital signature scheme in ideal class groups of quadratic fields, using q as modulus, which denotes the prime divisors of ideal class numbers of quadratic fields. Security of the new signature scheme is based fully on CL-DLP. This paper also investigates realization of the scheme, and proposes the concrete technique. In addition, the technique introduced in the paper can be utilized to realize signature schemes of other kinds.

  5. PERFORMANCE COMPARISON OF CELL-BASED AND PACKET-BASED SWITCHING SCHEMES FOR SHARED MEMORY SWITCHES

    Institute of Scientific and Technical Information of China (English)

    Xi Kang; Ge Ning; Feng Chongxi

    2004-01-01

    Shared Memory (SM) switches are widely used for its high throughput, low delay and efficient use of memory. This paper compares the performance of two prominent switching schemes of SM packet switches: Cell-Based Switching (CBS) and Packet-Based Switching (PBS).Theoretical analysis is carried out to draw qualitative conclusion on the memory requirement,throughput and packet delay of the two schemes. Furthermore, simulations are carried out to get quantitative results of the performance comparison under various system load, traffic patterns,and memory sizes. Simulation results show that PBS has the advantage of shorter time delay while CBS has lower memory requirement and outperforms in throughput when the memory size is limited. The comparison can be used for tradeoff between performance and complexity in switch design.

  6. Design and simulation of a fuel cell hybrid emergency power system for a more electric aircraft: Evaluation of energy management schemes

    Science.gov (United States)

    Njoya Motapon, Souleman

    As the aircraft industries are moving toward more electric aircraft (MEA), the electrical peak load seen by the main and emergency generators becomes higher than in conventional aircraft. Consequently, there is a major concern regarding the aircraft emergency system, which consists of a ram air turbine (RAT) or air driven generator (ADG), to fulfill the load demand during critical situations; particularly at low aircraft speed where the output power is very low. A potential solution under study by most aircraft manufacturers is to replace the air turbine by a fuel cell hybrid system, consisting of fuel cell combined with other high power density sources such as supercapacitors or lithium-ion batteries. To ensure the fuel cell hybrid system will be able to meet the load demand, it must be properly designed and an effective energy management strategy must be tested with real situations load profile. This work aims at designing a fuel cell emergency power system of a more electric aircraft and comparing different energy management schemes (EMS); with the goal to ensure the load demand is fully satisfied within the constraints of each energy source. The fuel cell hybrid system considered in this study consists of fuel cell, lithium-ion batteries and supercapacitors, along with associated DC-DC and DC-AC converters. The energy management schemes addressed are state-of-the-art, most commonly used energy management techniques in fuel cell vehicle applications and include: the state machine control strategy, the rule based fuzzy logic strategy, the classical PI control strategy, the frequency decoupling/fuzzy logic control strategy and the equivalent consumption minimization strategy (ECMS). Moreover, a new optimal scheme based on maximizing the instantaneous energy of batteries/supercapacitors, to improve the fuel economy is proposed. An off-line optimization based scheme is also developed to ascertain the validity of the proposed strategy in terms of fuel consumption

  7. A classification scheme for analyzing mobile apps used to prevent and manage disease in late life.

    Science.gov (United States)

    Wang, Aiguo; An, Ning; Lu, Xin; Chen, Hongtu; Li, Changqun; Levkoff, Sue

    2014-02-17

    There are several mobile apps that offer tools for disease prevention and management among older adults, and promote health behaviors that could potentially reduce or delay the onset of disease. A classification scheme that categorizes apps could be useful to both older adult app users and app developers. The objective of our study was to build and evaluate the effectiveness of a classification scheme that classifies mobile apps available for older adults in the "Health & Fitness" category of the iTunes App Store. We constructed a classification scheme for mobile apps according to three dimensions: (1) the Precede-Proceed Model (PPM), which classifies mobile apps in terms of predisposing, enabling, and reinforcing factors for behavior change; (2) health care process, specifically prevention versus management of disease; and (3) health conditions, including physical health and mental health. Content analysis was conducted by the research team on health and fitness apps designed specifically for older adults, as well as those applicable to older adults, released during the months of June and August 2011 and August 2012. Face validity was assessed by a different group of individuals, who were not related to the study. A reliability analysis was conducted to confirm the accuracy of the coding scheme of the sample apps in this study. After applying sample inclusion and exclusion criteria, a total of 119 apps were included in the study sample, of which 26/119 (21.8%) were released in June 2011, 45/119 (37.8%) in August 2011, and 48/119 (40.3%) in August 2012. Face validity was determined by interviewing 11 people, who agreed that this scheme accurately reflected the nature of this application. The entire study sample was successfully coded, demonstrating satisfactory inter-rater reliability by two independent coders (95.8% initial concordance and 100% concordance after consensus was reached). The apps included in the study sample were more likely to be used for the

  8. Comparative Study between Two Schemes of Active-Control-Based Mechatronic Inerter

    Directory of Open Access Journals (Sweden)

    He Lingduo

    2017-01-01

    Full Text Available Based on force-current analogy and velocity-voltage analogy in the theory of electromechanical analogy, the inerter is a device that corresponded to the capacitor completely where conquers the nature restriction of mass, what’s more, it is significant to improve the ratio of the inerter’s inertance to its mass for mechanical networks synthesis. And according to the principle of active-control-based mechatronic inerter, we present two implementation schemes. One was based on linear motor, and the other was based on the ball screw and rotary motor. We introduced the implementation methods and established theoretical model of the two schemes, then compared the ratio of the inerter’s inertance to its mass for the two schemes. Finally, we consider the scheme is better which was based on the ball screw and rotary motor.

  9. Curve interpolation based on Catmull-Clark subdivision scheme

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    An efficient algorithm for curve interpolation is proposed. The algorithm can produce a subdivision surface that can interpolate the predefined cubic B-spline curves by applying the Catmull-Clark scheme to a polygonal mesh containing "symmetric zonal meshes", which possesses some special properties. Many kinds of curve interpolation problems can be dealt with by this algorithm, such as interpolating single open curve or closed curve, a mesh of nonintersecting or intersecting curve. The interpolating surface is C2 everywhere excepting at a finite number of points. At the same time, sharp creases can also be modeled on the limit subdivision surface by duplicating the vertices of the tagged edges of initial mesh, i.e. the surface is only C0 along the cubic B-spline curve that is defined by the tagged edges. Because of being simple and easy to implement, this method can be used for product shape design and graphic software development.

  10. Sparse Parallel MRI Based on Accelerated Operator Splitting Schemes

    Science.gov (United States)

    Xie, Weisi; Su, Zhenghang

    2016-01-01

    Recently, the sparsity which is implicit in MR images has been successfully exploited for fast MR imaging with incomplete acquisitions. In this paper, two novel algorithms are proposed to solve the sparse parallel MR imaging problem, which consists of l1 regularization and fidelity terms. The two algorithms combine forward-backward operator splitting and Barzilai-Borwein schemes. Theoretically, the presented algorithms overcome the nondifferentiable property in l1 regularization term. Meanwhile, they are able to treat a general matrix operator that may not be diagonalized by fast Fourier transform and to ensure that a well-conditioned optimization system of equations is simply solved. In addition, we build connections between the proposed algorithms and the state-of-the-art existing methods and prove their convergence with a constant stepsize in Appendix. Numerical results and comparisons with the advanced methods demonstrate the efficiency of proposed algorithms. PMID:27746824

  11. Analysis on Stability of a Network Based on RED Scheme

    Directory of Open Access Journals (Sweden)

    Shengbo Hu

    2011-04-01

    Full Text Available The RED scheme allows to prevent global synchronization of the sources associated with drop-tail buffers. However, from a control point of view, the drop-tail discipline could lead to strong oscillations and complex behavior of the system. In this paper, the behavior of TCP in high bandwidth-delay product network is analyzed. Secondly, a model of TCP network using RED is described, including RED drop function and model of TCP source. Thirdly, the linear analysis of a single link topology is focused. Finally, a sufficient condition for the stability of a network using RED is given and an engineering approach to select network and protocols’ parameters that lead to stable operation of the linear feedback control system is presented.

  12. Multiple time scale based reduction scheme for nonlinear chemical dynamics

    Science.gov (United States)

    Das, D.; Ray, D. S.

    2013-07-01

    A chemical reaction is often characterized by multiple time scales governing the kinetics of reactants, products and intermediates. We eliminate the fast relaxing intermediates in autocatalytic reaction by transforming the original system into a new one in which the linearized part is diagonal. This allows us to reduce the dynamical system by identifying the associated time scales and subsequent adiabatic elimination of the fast modes. It has been shown that the reduced system sustains the robust qualitative signatures of the original system and at times the generic form of the return map for the chaotic system from which complex dynamics stems out in the original system can be identified. We illustrate the scheme for a three-variable cubic autocatalytic reaction and four-variable peroxidase-oxidase reaction.

  13. Network-based Arbitrated Quantum Signature Scheme with Graph State

    Science.gov (United States)

    Ma, Hongling; Li, Fei; Mao, Ningyi; Wang, Yijun; Guo, Ying

    2017-08-01

    Implementing an arbitrated quantum signature(QAS) through complex networks is an interesting cryptography technology in the literature. In this paper, we propose an arbitrated quantum signature for the multi-user-involved networks, whose topological structures are established by the encoded graph state. The determinative transmission of the shared keys, is enabled by the appropriate stabilizers performed on the graph state. The implementation of this scheme depends on the deterministic distribution of the multi-user-shared graph state on which the encoded message can be processed in signing and verifying phases. There are four parties involved, the signatory Alice, the verifier Bob, the arbitrator Trent and Dealer who assists the legal participants in the signature generation and verification. The security is guaranteed by the entanglement of the encoded graph state which is cooperatively prepared by legal participants in complex quantum networks.

  14. A novel dynamical community detection algorithm based on weighting scheme

    Science.gov (United States)

    Li, Ju; Yu, Kai; Hu, Ke

    2015-12-01

    Network dynamics plays an important role in analyzing the correlation between the function properties and the topological structure. In this paper, we propose a novel dynamical iteration (DI) algorithm, which incorporates the iterative process of membership vector with weighting scheme, i.e. weighting W and tightness T. These new elements can be used to adjust the link strength and the node compactness for improving the speed and accuracy of community structure detection. To estimate the optimal stop time of iteration, we utilize a new stability measure which is defined as the Markov random walk auto-covariance. We do not need to specify the number of communities in advance. It naturally supports the overlapping communities by associating each node with a membership vector describing the node's involvement in each community. Theoretical analysis and experiments show that the algorithm can uncover communities effectively and efficiently.

  15. AN IMPROVED DOS-RESISTANT ID-BASED PASSWORD AUTHENTICATION SCHEME WITHOUT USING SMART CARD

    Institute of Scientific and Technical Information of China (English)

    Wen Fengtong; Li Xuelei; Cui Shenjun

    2011-01-01

    In 2010,Hwang,et al.proposed a 'DoS-resistant ID-based password authentication scheme using smart cards' as an improvement of Kim-Lee-Yoo's ‘ID-based password authentication scheme'.In this paper,we cryptanalyze Hwang,et al.'s scheme and point out that the revealed session key could threat the security of the scheme.We demonstrate that extracting information from smart cards is equal to knowing the session key.Thus known session key attacks are also effective under the assumption that the adversary could obtain the information stored in the smart cards.We proposed an improved scheme with security analysis to remedy the weaknesses of Hwang,et al.'s scheme.The new scheme does not only keep all the merits of the original,but also provides several additional phases to improve the flexibility.Finally,the improved scheme is more secure,efficient,practical,and convenient,because elliptic curve cryptosystem is introduced,the expensive smart cards and synchronized clock system are replaced by mobile devices and nonces.

  16. A target coverage scheduling scheme based on genetic algorithms in directional sensor networks.

    Science.gov (United States)

    Gil, Joon-Min; Han, Youn-Hee

    2011-01-01

    As a promising tool for monitoring the physical world, directional sensor networks (DSNs) consisting of a large number of directional sensors are attracting increasing attention. As directional sensors in DSNs have limited battery power and restricted angles of sensing range, maximizing the network lifetime while monitoring all the targets in a given area remains a challenge. A major technique to conserve the energy of directional sensors is to use a node wake-up scheduling protocol by which some sensors remain active to provide sensing services, while the others are inactive to conserve their energy. In this paper, we first address a Maximum Set Covers for DSNs (MSCD) problem, which is known to be NP-complete, and present a greedy algorithm-based target coverage scheduling scheme that can solve this problem by heuristics. This scheme is used as a baseline for comparison. We then propose a target coverage scheduling scheme based on a genetic algorithm that can find the optimal cover sets to extend the network lifetime while monitoring all targets by the evolutionary global search technique. To verify and evaluate these schemes, we conducted simulations and showed that the schemes can contribute to extending the network lifetime. Simulation results indicated that the genetic algorithm-based scheduling scheme had better performance than the greedy algorithm-based scheme in terms of maximizing network lifetime.

  17. Knowledge-Based Trajectory Error Pattern Method Applied to an Active Force Control Scheme

    Directory of Open Access Journals (Sweden)

    Endra Pitowarno, Musa Mailah, Hishamuddin Jamaluddin

    2012-08-01

    Full Text Available The active force control (AFC method is known as a robust control scheme that dramatically enhances the performance of a robot arm particularly in compensating the disturbance effects. The main task of the AFC method is to estimate the inertia matrix in the feedback loop to provide the correct (motor torque required to cancel out these disturbances. Several intelligent control schemes have already been introduced to enhance the estimation methods of acquiring the inertia matrix such as those using neural network, iterative learning and fuzzy logic. In this paper, we propose an alternative scheme called Knowledge-Based Trajectory Error Pattern Method (KBTEPM to suppress the trajectory track error of the AFC scheme. The knowledge is developed from the trajectory track error characteristic based on the previous experimental results of the crude approximation method. It produces a unique, new and desirable error pattern when a trajectory command is forced. An experimental study was performed using simulation work on the AFC scheme with KBTEPM applied to a two-planar manipulator in which a set of rule-based algorithm is derived. A number of previous AFC schemes are also reviewed as benchmark. The simulation results show that the AFC-KBTEPM scheme successfully reduces the trajectory track error significantly even in the presence of the introduced disturbances.Key Words:  Active force control, estimated inertia matrix, robot arm, trajectory error pattern, knowledge-based.

  18. EBAA:An effcient broadcast authentication scheme for ADS-B communication based on IBS-MR

    Institute of Scientific and Technical Information of China (English)

    Yang Haomiao; Huang Rongshun; Wang Xiaofen; Deng Jiang; Chen Ruidong

    2014-01-01

    Automatic dependent surveillance-broadcast (ADS-B) systems can broadcast satellite-based aircraft position, identification, etc., periodically, and are now on track to replace radar to become the backbone of next-generation air traffic management (ATM) systems. However, ADS-B systems suffer severe cyber-security problems due to the broadcast-type data link and the lack of designed-in security measures. Especially, since ADS-B messages are unauthenticated, it is easy to insert fake aircraft into a system via spoofing or insertion of false messages. Unfortu-nately, the authentication for ADS-B messages has not yet been well studied. In this paper, based on identity-based signature with message recovery (IBS-MR), an efficient broadcast authentication scheme for ADS-B messages is proposed. The security analysis demonstrates that the scheme can achieve authenticity and integrity of ADS-B broadcast messages, as well as adaptive evolution of broadcasters’ private keys. The performance evaluation shows that the scheme is computationally efficient for typical avionics devices with limited resources. Furthermore, the scheme achieves low communication overhead since broadcast messages can be recovered from signatures, and thus it is suitable for low-bandwidth ADS-B data link.

  19. A New Loss-Tolerant Image Encryption Scheme Based on Secret Sharing and Two Chaotic Systems

    Directory of Open Access Journals (Sweden)

    Li Li

    2012-04-01

    Full Text Available In this study, we propose an efficient loss-tolerant image encryption scheme that protects both confidentiality and loss-tolerance simultaneously in shadow images. In this scheme, we generate the key sequence based on two chaotic maps and then encrypt the image during the sharing phase based on Shamir’s method. Experimental results show a better performance of the proposed scheme for different images than other methods from human vision. Security analysis confirms a high probability to resist both brute-force and collusion attacks.

  20. Training-Based Schemes are Suboptimal for High Rate Asynchronous Communication

    CERN Document Server

    Chandar, Venkat; Wornell, Gregory W

    2009-01-01

    We consider asynchronous point-to-point communication. Building on a recently developed model, we show that training based schemes, i.e., communication strategies that separate synchronization from information transmission, perform suboptimally at high rate.

  1. An Improved MAC Scheme of HORNET Based on Node Structure with Variable Optical Buffer

    Institute of Scientific and Technical Information of China (English)

    Nian Fang; Lutang Wang; Zhaoming Huang

    2003-01-01

    An improved unslotted CSMA/CA MAC scheme of HORNET based on the node structure with variable optical buffer is reported. It can be used for transmitting high effectively all variable IP packets in the WDM network.

  2. Participatory innovation process for testing new practices for soil fertility management in Chókwè Irrigation Scheme (Mozambique)

    Science.gov (United States)

    Sánchez Reparaz, Maite; de Vente, Joris; Famba, Sebastiao; Rougier, Jean-Emmanuel; Ángel Sánchez-Monedero, Miguel; Barberá, Gonzalo G.

    2015-04-01

    Integrated water and nutrient management are key factors to increase productivity and to reduce the yield gap in irrigated systems in Sub-Saharan Africa. These two elements are affected by an ensemble of abiotic, biotic, management and socio-economic factors that need to be taken into account to reduce the yield gap, as well as farmers' perceptions and knowledge. In the framework of the project European Union and African Union cooperative research to increase Food production in irrigated farming systems in Africa (EAU4Food project) we are carrying out a participatory innovation process in Chókwè irrigation scheme (Mozambique) based on stakeholders engagement, to test new practices for soil fertility management that can increase yields reducing costs. Through a method combining interviews with three farmers' associations and other relevant stakeholders and soil sampling from the interviewed farmers' plots with the organization of Communities of Practices, we tried to capture how soil fertility is managed by farmers, the constraints they find as well as their perceptions about soil resources. This information was the basis to design and conduct a participatory innovation process where compost made with rice straw and manure is being tested by a farmers' association. Most important limitations of the method are also evaluated. Our results show that socio-economic characteristics of farmers condition how they manage soil fertility and their perceptions. The difficulties they face to adopt new practices for soil fertility management, mainly related to economic resources limitations, labour availability, knowledge time or farm structure, require a systemic understanding that takes into account abiotic, biotic, management and socio-economic factors and their implication as active stakeholders in all phases of the innovation process.

  3. A Non-symmetric Digital Image Secure Communication Scheme Based on Generalized Chaos Synchronization System

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiao-Hong; MIN Le-Quan

    2005-01-01

    Based on a generalized chaos synchronization system and a discrete Sinai map, a non-symmetric true color(RGB) digital image secur e communication scheme is proposed. The scheme first changes an ordinary RGB digital image with 8 bits into unrecognizable disorder codes and then transforms the disorder codes into an RGB digital image with 16 bits for transmitting. A receiver uses a non-symmetric key to verify the authentication of the received data origin,and decrypts the ciphertext. The scheme can encrypt and decrypt most formatted digital RGB images recognized by computers, and recover the plaintext almost without any errors. The scheme is suitable to be applied in network image communications. The analysis of the key space, sensitivity of key parameters, and correlation of encrypted images imply that this scheme has sound security.

  4. A RBF Based Local Gridfree Scheme for Unsteady Convection-Diffusion Problems

    Directory of Open Access Journals (Sweden)

    Sanyasiraju VSS Yedida

    2009-12-01

    Full Text Available In this work a Radial Basis Function (RBF based local gridfree scheme has been presented for unsteady convection diffusion equations. Numerical studies have been made using multiquadric (MQ radial function. Euler and a three stage Runge-Kutta schemes have been used for temporal discretization. The developed scheme is compared with the corresponding finite difference (FD counterpart and found that the solutions obtained using the former are more superior. As expected, for a fixed time step and for large nodal densities, thought the Runge-Kutta scheme is able to maintain higher order of accuracy over the Euler method, the temporal discretization is independent of the improvement in the solution which in the developed scheme has been achived by optimizing the shape parameter of the RBF.

  5. A multi-label image annotation scheme based on improved SVM multiple kernel learning

    Science.gov (United States)

    Jin, Cong; Jin, Shu-Wei

    2017-02-01

    Multi-label image annotation (MIA) has been widely studied during recent years and many MIA schemes have been proposed. However, the most existing schemes are not satisfactory. In this paper, an improved multiple kernel learning (IMKL) method of support vector machine (SVM) is proposed to improve the classification accuracy of SVM, then a novel MIA scheme based on IMKL is presented, which uses the discriminant loss to control the number of top semantic labels, and the feature selection approach is also used for improving the performance of MIA. The experiment results show that proposed MIA scheme achieves higher the performance than the existing other MIA schemes, its performance is satisfactory for large image dataset.

  6. Asynchronous error-correcting secure communication scheme based on fractional-order shifting chaotic system

    Science.gov (United States)

    Chao, Luo

    2015-11-01

    In this paper, a novel digital secure communication scheme is firstly proposed. Different from the usual secure communication schemes based on chaotic synchronization, the proposed scheme employs asynchronous communication which avoids the weakness of synchronous systems and is susceptible to environmental interference. Moreover, as to the transmission errors and data loss in the process of communication, the proposed scheme has the ability to be error-checking and error-correcting in real time. In order to guarantee security, the fractional-order complex chaotic system with the shifting of order is utilized to modulate the transmitted signal, which has high nonlinearity and complexity in both frequency and time domains. The corresponding numerical simulations demonstrate the effectiveness and feasibility of the scheme.

  7. Optimal Scheme Selection of Agricultural Production Structure Adjustment - Based on DEA Model; Punjab (Pakistan)

    Institute of Scientific and Technical Information of China (English)

    Zeeshan Ahmad; Meng Jun; Muhammad Abdullah; Mazhar Nadeem Ishaq; Majid Lateef; Imran Khan

    2015-01-01

    This paper used the modern evaluation method of DEA (Data Envelopment Analysis) to assess the comparative efficiency and then on the basis of this among multiple schemes chose the optimal scheme of agricultural production structure adjustment. Based on the results of DEA model, we dissected scale advantages of each discretionary scheme or plan. We examined scale advantages of each discretionary scheme, tested profoundly a definitive purpose behind not-DEA efficient, which elucidated the system and methodology to enhance these discretionary plans. At the end, another method had been proposed to rank and select the optimal scheme. The research was important to guide the practice if the modification of agricultural production industrial structure was carried on.

  8. A Sentiment Delivering Estimate Scheme Based on Trust Chain in Mobile Social Network

    Directory of Open Access Journals (Sweden)

    Meizi Li

    2015-01-01

    Full Text Available User sentiment analysis has become a flourishing frontier in data mining mobile social network platform since the mobile social network plays a significant role in users’ daily communication and sentiment interaction. This study studies the scheme of sentiment estimate by using the users’ trustworthy relationships for evaluating sentiment delivering. First, we address an overview of sentiment delivering estimate scheme and propose its related definitions, that is, trust chain among users, sentiment semantics, and sentiment ontology. Second, this study proposes the trust chain model and its evaluation method, which is composed of evaluation of atomic, serial, parallel, and combined trust chains. Then, we propose sentiment modeling method by presenting its modeling rules. Further, we propose the sentiment delivering estimate scheme from two aspects: explicit and implicit sentiment delivering estimate schemes, based on trust chain and sentiment modeling method. Finally, examinations and results are given to further explain effectiveness and feasibility of our scheme.

  9. Breaking and Fixing of an Identity Based Multi-Signcryption Scheme

    Science.gov (United States)

    Selvi, S. Sharmila Deva; Vivek, S. Sree; Rangan, C. Pandu

    Signcryption is a cryptographic primitive that provides authentication and confidentiality simultaneously in a single logical step. It is often required that multiple senders have to signcrypt a single message to a certain receiver. Obviously, it is inefficient to signcrypt the messages separately. An efficient alternative is to go for multi-signcryption. The concept of multi-signcryption is similar to that of multi-signatures with the added property - confidentiality. Recently, Jianhong et al. proposed an identity based multi-signcryption scheme. They claimed that their scheme is secure against adaptive chosen ciphertext attack and it is existentially unforgeable. In this paper, we show that their scheme is not secure against chosen plaintext attack and is existentially forgeable, we also provide a fix for the scheme and prove formally that the improved scheme is secure against both adaptive chosen ciphertext attack and existential forgery.

  10. RTP-Packets' Loss Recovery Scheme Based on Layered Buffer-Routers

    Institute of Scientific and Technical Information of China (English)

    XU Xian-bin; YU Wei; CHEN Xin-meng

    2004-01-01

    This paper introduces an RTP-packets' loss recovery scheme in MPEG-4 playback type multicast application model, which is based on retransmission scheme. Through the auxiliary and coordinated buffer playing scheme of layered "buffer-routers", the RTP-packets' loss recovery in limited time is made possible. We consider in the scheme to handle retransmission request with buffer waiting when network congestion occurs. Thus, neither the degree of congestion will be worsened nor the retransmission request will be lost when sending the request to higher-level buffer router. The RTP-packets' loss recovery scheme suggested by us is not only applied to MPEG-4 multicast application in LAN, but also can be extended to more spacious WAN (wide area network) when user groups comparatively centralize in certain number of local areas.

  11. Security analysis of the unrestricted identity-based aggregate signature scheme.

    Directory of Open Access Journals (Sweden)

    Kwangsu Lee

    Full Text Available Aggregate signatures allow anyone to combine different signatures signed by different signers on different messages into a short signature. An ideal aggregate signature scheme is an identity-based aggregate signature (IBAS scheme that supports full aggregation since it can reduce the total transmitted data by using an identity string as a public key and anyone can freely aggregate different signatures. Constructing a secure IBAS scheme that supports full aggregation in bilinear maps is an important open problem. Recently, Yuan et al. proposed such a scheme and claimed its security in the random oracle model under the computational Diffie-Hellman assumption. In this paper, we show that there is an efficient forgery on their IBAS scheme and that their security proof has a serious flaw.

  12. FINGERPRINT-BASED KEY BINDING/RECOVERING SCHEME BASED ON FUZZY VAULT

    Institute of Scientific and Technical Information of China (English)

    Feng Quan; Su Fei; Cai Anni

    2008-01-01

    This letter proposes fingerprint-based key binding/recovering with fuzzy vault. Fingerprint minutiae data and the cryptographic key are merged together by a multivariable linear function. First,the minutiae data are bound by a set of random data through the linear function. The number of the function's variables is determined by the required number of matched minutiae. Then, a new key derived from the random data is used to encrypt the cryptographic key. Lastly, the binding data are protected using fuzzy vault scheme. The proposed scheme provides the system with the flexibility to use changeable number of minutiae to bind/recover the protected key and a unified method regardless of the length of the key.

  13. Comparison of horizontal dust fluxes simulated with two dust emission schemes based on field experiments in Xinjiang, China

    Science.gov (United States)

    Yang, Xinghua; Yang, Fan; Liu, Xinchun; Huo, Wen; He, Qing; Mamtimin, Ali; Zhang, Qingyu

    2016-10-01

    Horizontal dust fluxes were simulated with two different dust emission schemes developed by Marticorena and Shao (hereinafter referred to as the M scheme, S scheme, and S scheme corrections), based on field experiments over a bare desert surface and a vegetated desert surface from May 19 to June 18, 2010 in Xinjiang, China. The M scheme produced a much higher dust emission than the S schemes over different surface conditions, with the emission being about 4 times larger than that produced by the S schemes over the bare desert, and 3 to 200 times larger over the vegetated surface. Compared to observations, the missing report rate of wind erosion events was about 30 % for the S schemes and about 10 % for the M scheme over the bare desert surface, while all schemes had a false alarm rate of wind erosion events over the vegetated desert surface. The total dust emission from the bare desert surface during the study period was 674.4, 551.5, 595.2, and 2995.8 kg/m for observation, the S scheme, S scheme correction 2, and M scheme, respectively. Total dust emission from the vegetated desert surface was 1.6, 0, 55.5, 0.9, and 227.7 kg/m for observation, the S scheme, S scheme correction 1, S scheme correction 2, and M scheme, respectively.

  14. A Contourlet-Based Embedded Image Coding Scheme on Low Bit-Rate

    Science.gov (United States)

    Song, Haohao; Yu, Songyu

    Contourlet transform (CT) is a new image representation method, which can efficiently represent contours and textures in images. However, CT is a kind of overcomplete transform with a redundancy factor of 4/3. If it is applied to image compression straightforwardly, the encoding bit-rate may increase to meet a given distortion. This fact baffles the coding community to develop CT-based image compression techniques with satisfactory performance. In this paper, we analyze the distribution of significant contourlet coefficients in different subbands and propose a new contourlet-based embedded image coding (CEIC) scheme on low bit-rate. The well-known wavelet-based embedded image coding (WEIC) algorithms such as EZW, SPIHT and SPECK can be easily integrated into the proposed scheme by constructing a virtual low frequency subband, modifying the coding framework of WEIC algorithms according to the structure of contourlet coefficients, and adopting a high-efficiency significant coefficient scanning scheme for CEIC scheme. The proposed CEIC scheme can provide an embedded bit-stream, which is desirable in heterogeneous networks. Our experiments demonstrate that the proposed scheme can achieve the better compression performance on low bit-rate. Furthermore, thanks to the contourlet adopted in the proposed scheme, more contours and textures in the coded images are preserved to ensure the superior subjective quality.

  15. The Financial Analysis of a Modern Scheme for Managing Waste Proposed for the Urban Community Arieş, Cluj County

    Directory of Open Access Journals (Sweden)

    Lucia Monica SCORȚAR

    2009-10-01

    Full Text Available This paper presents a scheme for managingwaste, proposed for the urban community of Arieş,Cluj County, in which we are going to show themain activities that should be accomplished withthe support of the local public administration.Based on the analysis of the waste flows, thedemographic trends and the waste generatingtrends, we propose a scheme for managingwaste that has a major investment component,an administrative re-organizing component andan educational one. We suggest a scheme whichincludes advanced techniques and methods fortreating waste. Moreover, we demonstrated thatthe efficiency of the scheme cannot be conceivedoutside a circuit for valorizing and recycling theuseful materials contained in the waste.

  16. A Fuzzy Identity-Based Signature Scheme from Lattices in the Standard Model

    Directory of Open Access Journals (Sweden)

    Chunli Yang

    2014-01-01

    Full Text Available A fuzzy identity-based signature (FIBS scheme allows a user with identity ID to issue a signature that could be verified with identity ID' if and only if ID and ID' lie within a certain distance. To obtain an FIBS scheme that can resist known quantum attacks, we use the double-trapdoor technique from ABB10a for secret key extracting and the vanishing trapdoor technique from Boyen10 for message signing. In addition, in order to reflect the functionality of fuzziness, Shamir secret sharing scheme is also used in our construction. In this paper, we propose an FIBS scheme from lattices and prove that this new scheme achieves strong unforgeability under selective chosen-identity and adaptive chosen-message attacks (SU-sID-CMA in the standard model. To the best of our knowledge, our scheme is not only the first FIBS scheme from lattices without random oracles but also the first FIBS scheme that achieves strong unforgeability.

  17. A Temporal Credential-Based Mutual Authentication with Multiple-Password Scheme for Wireless Sensor Networks.

    Science.gov (United States)

    Liu, Xin; Zhang, Ruisheng; Liu, Qidong

    2017-01-01

    Wireless sensor networks (WSNs), which consist of a large number of sensor nodes, have become among the most important technologies in numerous fields, such as environmental monitoring, military surveillance, control systems in nuclear reactors, vehicle safety systems, and medical monitoring. The most serious drawback for the widespread application of WSNs is the lack of security. Given the resource limitation of WSNs, traditional security schemes are unsuitable. Approaches toward withstanding related attacks with small overhead have thus recently been studied by many researchers. Numerous studies have focused on the authentication scheme for WSNs, but most of these works cannot achieve the security performance and overhead perfectly. Nam et al. proposed a two-factor authentication scheme with lightweight sensor computation for WSNs. In this paper, we review this scheme, emphasize its drawbacks, and propose a temporal credential-based mutual authentication with a multiple-password scheme for WSNs. Our scheme uses multiple passwords to achieve three-factor security performance and generate a session key between user and sensor nodes. The security analysis phase shows that our scheme can withstand related attacks, including a lost password threat, and the comparison phase shows that our scheme involves a relatively small overhead. In the comparison of the overhead phase, the result indicates that more than 95% of the overhead is composed of communication and not computation overhead. Therefore, the result motivates us to pay further attention to communication overhead than computation overhead in future research.

  18. A Temporal Credential-Based Mutual Authentication with Multiple-Password Scheme for Wireless Sensor Networks

    Science.gov (United States)

    Zhang, Ruisheng; Liu, Qidong

    2017-01-01

    Wireless sensor networks (WSNs), which consist of a large number of sensor nodes, have become among the most important technologies in numerous fields, such as environmental monitoring, military surveillance, control systems in nuclear reactors, vehicle safety systems, and medical monitoring. The most serious drawback for the widespread application of WSNs is the lack of security. Given the resource limitation of WSNs, traditional security schemes are unsuitable. Approaches toward withstanding related attacks with small overhead have thus recently been studied by many researchers. Numerous studies have focused on the authentication scheme for WSNs, but most of these works cannot achieve the security performance and overhead perfectly. Nam et al. proposed a two-factor authentication scheme with lightweight sensor computation for WSNs. In this paper, we review this scheme, emphasize its drawbacks, and propose a temporal credential-based mutual authentication with a multiple-password scheme for WSNs. Our scheme uses multiple passwords to achieve three-factor security performance and generate a session key between user and sensor nodes. The security analysis phase shows that our scheme can withstand related attacks, including a lost password threat, and the comparison phase shows that our scheme involves a relatively small overhead. In the comparison of the overhead phase, the result indicates that more than 95% of the overhead is composed of communication and not computation overhead. Therefore, the result motivates us to pay further attention to communication overhead than computation overhead in future research. PMID:28135288

  19. An efficient and secure dynamic ID-based authentication scheme for telecare medical information systems.

    Science.gov (United States)

    Chen, Hung-Ming; Lo, Jung-Wen; Yeh, Chang-Kuo

    2012-12-01

    The rapidly increased availability of always-on broadband telecommunication environments and lower-cost vital signs monitoring devices bring the advantages of telemedicine directly into the patient's home. Hence, the control of access to remote medical servers' resources has become a crucial challenge. A secure authentication scheme between the medical server and remote users is therefore needed to safeguard data integrity, confidentiality and to ensure availability. Recently, many authentication schemes that use low-cost mobile devices have been proposed to meet these requirements. In contrast to previous schemes, Khan et al. proposed a dynamic ID-based remote user authentication scheme that reduces computational complexity and includes features such as a provision for the revocation of lost or stolen smart cards and a time expiry check for the authentication process. However, Khan et al.'s scheme has some security drawbacks. To remedy theses, this study proposes an enhanced authentication scheme that overcomes the weaknesses inherent in Khan et al.'s scheme and demonstrated this scheme is more secure and robust for use in a telecare medical information system.

  20. Improvement of the ElGamal Based Remote Authentication Scheme Using Smart Cards

    Directory of Open Access Journals (Sweden)

    Yung-Cheng Lee

    2014-12-01

    Full Text Available Nowadays, we can easily obtain variety of services through networks. But due to the open environment, networks are vulnerable to many security threats. The remote user authentication scheme is one of the most widely used mechanisms for servers to authorize users to access the services. In 2009, Ramasamy and Muniyandi proposed a discrete logarithm based remote authentication scheme with smart cards. Their scheme provides mutual authentication and withstands the denial of service attack, forgery attack and parallel session attack. In this article, we show that their scheme is not a practical solution for remote access. It lacks key agreement mechanism and users cannot choose or update passwords freely. Moreover, their scheme cannot resist the stolen-verifier attack, off-line guessing attack, impersonation attack and smart-card-loss-attack. We propose an improved scheme to remedy the drawbacks. The improved scheme has the merits of providing mutual authentication and key agreement, while forward and backward secrecy are ensured as well. The users can choose and update their passwords freely. Furthermore, the scheme can also withstand many attacks such as the smart-card-loss-attack, the replay attack, the off-line guessing attack, the insider attack, the impersonation attack and the parallel session attack.

  1. A New Flux Splitting Scheme Based on Toro-Vazquez and HLL Schemes for the Euler Equations

    Directory of Open Access Journals (Sweden)

    Pascalin Tiam Kapen

    2014-01-01

    Full Text Available This paper presents a new flux splitting scheme for the Euler equations. The proposed scheme termed TV-HLL is obtained by following the Toro-Vazquez splitting (Toro and Vázquez-Cendón, 2012 and using the HLL algorithm with modified wave speeds for the pressure system. Here, the intercell velocity for the advection system is taken as the arithmetic mean. The resulting scheme is more accurate when compared to the Toro-Vazquez schemes and also enjoys the property of recognition of contact discontinuities and shear waves. Accuracy, efficiency, and other essential features of the proposed scheme are evaluated by analyzing shock propagation behaviours for both the steady and unsteady compressible flows. The accuracy of the scheme is shown in 1D test cases designed by Toro.

  2. IP Packet Size Entropy-Based Scheme for Detection of DoS/DDoS Attacks

    Science.gov (United States)

    Du, Ping; Abe, Shunji

    Denial of service (DoS) attacks have become one of the most serious threats to the Internet. Enabling detection of attacks in network traffic is an important and challenging task. However, most existing volume-based schemes can not detect short-term attacks that have a minor effect on traffic volume. On the other hand, feature-based schemes are not suitable for real-time detection because of their complicated calculations. In this paper, we develop an IP packet size entropy (IPSE)-based DoS/DDoS detection scheme in which the entropy is markedly changed when traffic is affected by an attack. Through our analysis, we find that the IPSE-based scheme is capable of detecting not only long-term attacks but also short-term attacks that are beyond the volume-based schemes' ability to detect. Moreover, we test our proposal using two typical Internet traffic data sets from DARPA and SINET, and the test results show that the IPSE-based detection scheme can provide detection of DoS/DDoS attacks not only in a local area network (DARPA) and but also in academic backbone network (SINET).

  3. A Novel Encryption scheme based on Double Based Canonical Number System

    Directory of Open Access Journals (Sweden)

    A.Chandra Sekhar

    2010-05-01

    Full Text Available Cryptography is the study of mathematical techniques related to aspects of information security such as confidentiality, data integrity, entity authentication, and data origin authentication. Recently, a non-standard number representation, called Double Base Number System (DBNS has found application in cryptography. In traditional number systems, there is one radix used to represent numbers.For example in decimal systems, numbers are expressed as sum of powers of 10. In DBNS numbers are represented as sum of product of powers of 2 radices. In the present paper, a cryptographic scheme is proposed using Double Based Canonical Number System .

  4. Performance Analysis Of Active Queue Management AQM In VOIP Using Different Voice Encoder Scheme

    Directory of Open Access Journals (Sweden)

    Samir Eid Mohammed

    2015-08-01

    Full Text Available Abstract Voice over Internet Protocol VoIP is a rapidly growing technology that enables transport of voice over data networks such as Ethernet Wide area networks WANs due to this important different codec scheme is developed to meet the QoS requirements. This thesis presents a comprehensive study about the impact of active queue management AQM on Voice over Internet Protocol VoIP quality of service using different codec scheme such as G711 G723 G729 and GSM using simulations tools. The evaluation is done using the OPNET Modeler which provides a convenient and easy-to-use platform for simulating large scale networks and this also give a power to go through different levels of designing a network even with the ability to program the mechanism you want which is used here to implement two types of AQM mechanism which is not included by default in the OPNET and these two mechanisms are ARED and GRED. The performance metrics used in the study are jitter throughput and delay. The study shows that G.711 and G729 codecs in a simulation gives a significant result for the performance of VoIP that codec G711 and G.729A has acceptable throughput and less deviation of received to transmit packet as compared to GSM and G.723 also average delay like end to end delay and Voice jitter is lesser in codec G711 and G.729 as compared to the other two referenced codecs.

  5. Review on buffer management schemes for packet queues in wired & wireless network

    Directory of Open Access Journals (Sweden)

    Shaheen C. Pathan,

    2015-08-01

    Full Text Available Mobile AdHoc Network (MANET is a wireless network with a set of mobile nodes that can communicate with each other with no access point and without any fixed infrastructure. But mobile devices usually have limited resources (battery power, memory, CPU which limit their transmission range. Hence, in order to conserve the limited resource, it is highly desirable that transmission should be as efficient as possible. MANET can be implemented in any environment because of its dynamic nature. For routing of information packets queuing is done at the buffer and transferred through intermediate nodes to the destination on priority basis which help to improve the overall network performance. This paper provides a review of various buffer management schemes for packet queues in wired & wireless networks (specialy MANET.

  6. On the security flaws in ID-based password authentication schemes for telecare medical information systems.

    Science.gov (United States)

    Mishra, Dheerendra

    2015-01-01

    Telecare medical information systems (TMIS) enable healthcare delivery services. However, access of these services via public channel raises security and privacy issues. In recent years, several smart card based authentication schemes have been introduced to ensure secure and authorized communication between remote entities over the public channel for the (TMIS). We analyze the security of some of the recently proposed authentication schemes of Lin, Xie et al., Cao and Zhai, and Wu and Xu's for TMIS. Unfortunately, we identify that these schemes failed to satisfy desirable security attributes. In this article we briefly discuss four dynamic ID-based authentication schemes and demonstrate their failure to satisfy desirable security attributes. The study is aimed to demonstrate how inefficient password change phase can lead to denial of server scenario for an authorized user, and how an inefficient login phase causes the communication and computational overhead and decrease the performance of the system. Moreover, we show the vulnerability of Cao and Zhai's scheme to known session specific temporary information attack, vulnerability of Wu and Xu's scheme to off-line password guessing attack, and vulnerability of Xie et al.'s scheme to untraceable on-line password guessing attack.

  7. Twin-Schnorr: A Security Upgrade for the Schnorr Identity-Based Identification Scheme

    Directory of Open Access Journals (Sweden)

    Ji-Jian Chin

    2015-01-01

    Full Text Available Most identity-based identification (IBI schemes proposed in recent literature are built using pairing operations. This decreases efficiency due to the high operation costs of pairings. Furthermore, most of these IBI schemes are proven to be secure against impersonation under active and concurrent attacks using interactive assumptions such as the one-more RSA inversion assumption or the one-more discrete logarithm assumption, translating to weaker security guarantees due to the interactive nature of these assumptions. The Schnorr-IBI scheme was first proposed through the Kurosawa-Heng transformation from the Schnorr signature. It remains one of the fastest yet most secure IBI schemes under impersonation against passive attacks due to its pairing-free design. However, when required to be secure against impersonators under active and concurrent attacks, it deteriorates greatly in terms of efficiency due to the protocol having to be repeated multiple times. In this paper, we upgrade the Schnorr-IBI scheme to be secure against impersonation under active and concurrent attacks using only the classical discrete logarithm assumption. This translates to a higher degree of security guarantee with only some minor increments in operational costs. Furthermore, because the scheme operates without pairings, it still retains its efficiency and superiority when compared to other pairing-based IBI schemes.

  8. Development of trigger scheme for the ICAL detector of India-based Neutrino Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Dasgupta, S., E-mail: sudeshnadasgupta@tifr.res.in [Department of High Energy Physics, Tata Institute of Fundamental Research, Mumbai 400005 (India); Mondal, N.K.; Samuel, D.; Saraf, M.N.; Satyanarayana, B.; Upadhya, S.S. [Department of High Energy Physics, Tata Institute of Fundamental Research, Mumbai 400005 (India)

    2012-06-21

    The India-based Neutrino Observatory (INO) collaboration has proposed to build a 50 kton magnetized Iron Calorimeter (ICAL) detector with the primary goal to study neutrino oscillations, employing Resistive Plate Chambers (RPCs) as active detector elements. Various aspects of a proposed trigger scheme for the ICAL detector are discussed. The associated chance trigger rates are calculated and the trigger efficiency of the scheme for the events of interest for the ICAL detector is determined. An approach toward the implementation of the scheme is also presented.

  9. Digital Multi-Signature Scheme Based on the Elliptic Curve Cryptosystem

    Institute of Scientific and Technical Information of China (English)

    Tzer-Shyong Chen; Kuo-Hsuan Huang; Yu-Fang Chung

    2004-01-01

    In the study,the digital multi-signature scheme,constructed by the integration of one-way hash function and identification scheme,are proposed based on the elliptic curve cryptosystem(ECC).To the efficiency in performance,the ECC has been generally regarded as positive; and the security caused by the Elliptic Curve Discrete Logarithm Problem(ECDLP)is highly also taken highly important.The main characteristic of the proposed scheme is that the length of the multi-signature is fixed rather than changeable and it will not increase with the number of group members.

  10. An image encryption scheme based on the MLNCML system using DNA sequences

    Science.gov (United States)

    Zhang, Ying-Qian; Wang, Xing-Yuan; Liu, Jia; Chi, Ze-Lin

    2016-07-01

    We propose a new image scheme based on the spatiotemporal chaos of the Mixed Linear-Nonlinear Coupled Map Lattices (MLNCML). This spatiotemporal chaotic system has more cryptographic features in dynamics than the system of Coupled Map Lattices (CML). In the proposed scheme, we employ the strategy of DNA computing and one time pad encryption policy, which can enhance the sensitivity to the plaintext and resist differential attack, brute-force attack, statistical attack and plaintext attack. Simulation results and theoretical analysis indicate that the proposed scheme has superior high security.

  11. Vector-lifting schemes based on sorting techniques for lossless compression of multispectral images

    Science.gov (United States)

    Benazza-Benyahia, Amel; Pesquet, Jean-Christophe

    2003-01-01

    In this paper, we introduce vector-lifting schemes which allow to generate very compact multiresolution representations, suitable for lossless and progressive coding of multispectral images. These new decomposition schemes exploit simultaneously the spatial and the spectral redundancies contained in multispectral images. When the spectral bands have different dynamic ranges, we improve dramatically the performances of the proposed schemes by a reversible histogram modification based on sorting permutations. Simulation tests carried out on real images allow to evaluate the performances of this new compression method. They indicate that the achieved compression ratios are higher than those obtained with currently used lossless coders.

  12. A Chaotic Communication Scheme Based on Generalized Synchronization and Hash Functions

    Institute of Scientific and Technical Information of China (English)

    XU Jiang-Feng; MIN Le-Quan; CHEN Guan-Rong

    2004-01-01

    @@ A new chaotic communication scheme based on generalized chaotic synchronization (GCS) and hash function transpositions is presented. The communication scheme has nonsymmetric secrete keys and its ability is similar to traditional digital signatures, i.e. a receiver can convince himself whether or not the sender's message contents have been modified. As a direct application of the scheme, a GCS system is designed by using Chen's chaotic circuit and is studied in some detail. The numerical simulation shows that this Chen GCS system has high security and is fast and reliable for secure Internet communications.

  13. A Fingerprint Encryption Scheme Based on Irreversible Function and Secure Authentication

    Directory of Open Access Journals (Sweden)

    Yijun Yang

    2015-01-01

    Full Text Available A fingerprint encryption scheme based on irreversible function has been designed in this paper. Since the fingerprint template includes almost the entire information of users’ fingerprints, the personal authentication can be determined only by the fingerprint features. This paper proposes an irreversible transforming function (using the improved SHA1 algorithm to transform the original minutiae which are extracted from the thinned fingerprint image. Then, Chinese remainder theorem is used to obtain the biokey from the integration of the transformed minutiae and the private key. The result shows that the scheme has better performance on security and efficiency comparing with other irreversible function schemes.

  14. A Fingerprint Encryption Scheme Based on Irreversible Function and Secure Authentication

    Science.gov (United States)

    Yu, Jianping; Zhang, Peng; Wang, Shulan

    2015-01-01

    A fingerprint encryption scheme based on irreversible function has been designed in this paper. Since the fingerprint template includes almost the entire information of users' fingerprints, the personal authentication can be determined only by the fingerprint features. This paper proposes an irreversible transforming function (using the improved SHA1 algorithm) to transform the original minutiae which are extracted from the thinned fingerprint image. Then, Chinese remainder theorem is used to obtain the biokey from the integration of the transformed minutiae and the private key. The result shows that the scheme has better performance on security and efficiency comparing with other irreversible function schemes. PMID:25873989

  15. Transfer Scheme Evaluation Model for a Transportation Hub based on Vectorial Angle Cosine

    Directory of Open Access Journals (Sweden)

    Li-Ya Yao

    2014-07-01

    Full Text Available As the most important node in public transport network, efficiency of a transport hub determines the entire efficiency of the whole transport network. In order to put forward effective transfer schemes, a comprehensive evaluation index system of urban transport hubs’ transfer efficiency was built, evaluation indexes were quantified, and an evaluation model of a multi-objective decision hub transfer scheme was established based on vectorial angle cosine. Qualitative and quantitative analysis on factors affecting transfer efficiency is conducted, which discusses the passenger satisfaction, transfer coordination, transfer efficiency, smoothness, economy, etc. Thus, a new solution to transfer scheme utilization was proposed.

  16. An Ultra-Low-Latency Geo-Routing Scheme for Team-Based Unmanned Vehicular Applications

    KAUST Repository

    Bader, Ahmed

    2016-02-26

    Results and lessons learned from the implementation of a novel ultra low-latency geo-routing scheme are presented in this paper. The geo-routing scheme is intended for team-based mobile systems whereby a cluster of unmanned autonomous vehicles are deployed to accomplish a critical mission under human supervision. The contention-free nature of the developed scheme lends itself to jointly achieve lower latency and higher throughput. Implementation challenges are presented and corresponding resolutions are discussed herewith. © 2015 IEEE.

  17. A fingerprint encryption scheme based on irreversible function and secure authentication.

    Science.gov (United States)

    Yang, Yijun; Yu, Jianping; Zhang, Peng; Wang, Shulan

    2015-01-01

    A fingerprint encryption scheme based on irreversible function has been designed in this paper. Since the fingerprint template includes almost the entire information of users' fingerprints, the personal authentication can be determined only by the fingerprint features. This paper proposes an irreversible transforming function (using the improved SHA1 algorithm) to transform the original minutiae which are extracted from the thinned fingerprint image. Then, Chinese remainder theorem is used to obtain the biokey from the integration of the transformed minutiae and the private key. The result shows that the scheme has better performance on security and efficiency comparing with other irreversible function schemes.

  18. The Catalog Management Strategy of Distributed Data Base Systems

    Institute of Scientific and Technical Information of China (English)

    周龙骧; 秦箕英

    1994-01-01

    In this paper the catalog management strategy of the successfully integrating and running DDBMS C-POREL is summarized.The new catalog management strategy and its implementation scheme are based on the analysis of the catalog management methods of the pioneer DDBMS.The goal of the new strategy is to improve the system efficiency.Analysis and practice show that this strategy is successful.

  19. Survey on Industry Requirements and Drivers for the Development of a Process-Related Certification Scheme for Ecodesign Implementation and Management

    DEFF Research Database (Denmark)

    Pigosso, Daniela Cristina Antelmi; Jakobsen, Maja; McAloone, Tim C.

    2014-01-01

    Despite the existence of a large amount of eco-labels and eco-standards for product declaration, there is still limited research for the development of process-related certification schemes dealing with ecodesign implementation and management. In order to identify companies’ drivers, barriers...... and expected benefits in regards to the development and application of process-related ecodesign certification schemes, a survey was carried out inthis research. This paper presents and discusses the main results obtained in the survey, which comprised the participation of more than 100 professionals from more...... than 25 countries. The results will be employed for the development of an ecodesign process-related certification scheme based on the Ecodesign Maturity Model (EcoM2)....

  20. A secure quantum key distribution scheme based on variable quantum encoding algorithms

    Institute of Scientific and Technical Information of China (English)

    Zhiwen Zhao; Yi Luo; Zhangji Zhao; Haiming Long

    2011-01-01

    The security of the quantum secret key plays a critical role in quantum communications. Thus far, one problem that still exists in existing protocols is the leakage of the length of the secret key. In this letter, based on variable quantum encoding algorithms, we propose a secure quantum key distribution scheme, which can overcome the security problem involving the leakage of the secret key. Security analysis shows that the proposed scheme is both secure and effective.%@@ The security of the quantum secret key plays a critical role in quantum communications.Thus far, one problem that still exists in existing protocols is the leakage of the length of the secret key.In this letter,based on variable quantum encoding algorithms, we propose a secure quantum key distribution scheme,which can overcome the security problem involving the leakage of the secret key.Security analysis shows that the proposed scheme is both secure and effective.

  1. Underwater Acoustic Communication Based on Pattern Time Delay Shift Coding Scheme

    Institute of Scientific and Technical Information of China (English)

    YIN Jing-wei; HUI Jun-ying; HUI Juan; YAO Zhi-xiang; WANG Yi-lin

    2006-01-01

    Underwater acoustic communication based on Pattern Time Delay Shift Coding (PDS) communication scheme is studied. The time delay shift values of the pattern are used to encode the digital information in the PDS scheme, which belongs to the Pulse Position Modulation (PPM). The duty cycle of the PDS scheme is small, so it can economize the power for communication. By use of different patterns for code division and different frequencies for channel division, the communication system is capable of mitigating the inter-symbol interference (ISI) caused by the multipath channel. The data rate of communication is 1000 bits/s at 8 kHz bandwidth. The receiver separates the channels by means of band-pass filters, and performs decoding by 4 copy-correlators to estimate the time delay shift value. Based on the theoretical analysis and numerical simulations, the PDS scheme is shown to be a robust and effective approach for underwater acoustic communication.

  2. Feedback control scheme of traffic jams based on the coupled map car-following model

    Science.gov (United States)

    Zhou, Tong; Sun, Di-Hua; Zhao, Min; Li, Hua-Min

    2013-09-01

    Based on the pioneering work of Konishi et al. [Phys. Rev. E (1999) 60 4000], a new feedback control scheme is presented to suppress traffic jams based on the coupled map car-following model under the open boundary condition. The effect of the safe headway on the traffic system is considered. According to the control theory, the condition under which traffic jams can be suppressed is analyzed. The results are compared with the previous results concerning congestion control. The simulations show that the suppression performance of our scheme on traffic jams is better than those of the previous schemes, although all the schemes can suppress traffic jams. The simulation results are consistent with theoretical analyses.

  3. Cryptanalysis of Chatterjee-Sarkar Hierarchical Identity-Based Encryption Scheme at PKC 06

    Science.gov (United States)

    Park, Jong Hwan; Lee, Dong Hoon

    In 2006, Chatterjee and Sarkar proposed a hierarchical identity-based encryption (HIBE) scheme which can support an unbounded number of identity levels. This property is particularly useful in providing forward secrecy by embedding time components within hierarchical identities. In this paper we show that their scheme does not provide the claimed property. Our analysis shows that if the number of identity levels becomes larger than the value of a fixed public parameter, an unintended receiver can reconstruct a new valid ciphertext and decrypt the ciphertext using his or her own private key. The analysis is similarly applied to a multi-receiver identity-based encryption scheme presented as an application of Chatterjee and Sarkar's HIBE scheme.

  4. A Co ding Scheme for Noisy Image Based on Layer Segmentation

    Institute of Scientific and Technical Information of China (English)

    LI Tao; TIAN Xin; XIONG Chengyi; TIAN Jinwen

    2016-01-01

    Heavy noises distribute in the images when imaging in a poor environment. The randomness of noises makes pixels distributing singularly, which weakens the 1-D piecewise smooth property of original scenes. Thus, wavelets-based compression method no longer works well. In this paper, a layer segmentation based compression scheme is proposed for gray images. Image textures and some high frequency noises are described in a high fre-quency layer while the coarse part of the image is described in the low frequency layer. The high frequency layer is represented by a joint dictionary, and the low frequency layer is coded with the traditional wavelets. The proposed scheme is tested on nature images and synthetic images. The results show that the proposed scheme achieves better rate-distortion performance compared with several com-peting compression systems. Besides, further degradation of edges is avoided by the proposed compression scheme.

  5. A Spectrum Handoff Scheme for Optimal Network Selection in NEMO Based Cognitive Radio Vehicular Networks

    Directory of Open Access Journals (Sweden)

    Krishan Kumar

    2017-01-01

    Full Text Available When a mobile network changes its point of attachments in Cognitive Radio (CR vehicular networks, the Mobile Router (MR requires spectrum handoff. Network Mobility (NEMO in CR vehicular networks is concerned with the management of this movement. In future NEMO based CR vehicular networks deployment, multiple radio access networks may coexist in the overlapping areas having different characteristics in terms of multiple attributes. The CR vehicular node may have the capability to make call for two or more types of nonsafety services such as voice, video, and best effort simultaneously. Hence, it becomes difficult for MR to select optimal network for the spectrum handoff. This can be done by performing spectrum handoff using Multiple Attributes Decision Making (MADM methods which is the objective of the paper. The MADM methods such as grey relational analysis and cost based methods are used. The application of MADM methods provides wider and optimum choice among the available networks with quality of service. Numerical results reveal that the proposed scheme is effective for spectrum handoff decision for optimal network selection with reduced complexity in NEMO based CR vehicular networks.

  6. Digital image communication scheme based on the breakup of spiral waves

    Science.gov (United States)

    Vaidelys, Martynas; Lu, Chen; Cheng, Yujie; Ragulskis, Minvydas

    2017-02-01

    A digital image communication scheme based on the breakup of spiral waves is presented in this paper. This communication system does not require spatially homogeneous random initial conditions. Moreover, the secret image is not embedded into the initial conditions of the evolving self-organizing patterns. Such features increase the security of the communication, but still enable an effective transmission of the secret image. Computational experiments are used to demonstrate the properties and efficiency of the proposed scheme.

  7. A Novel Bandwidth Efficient Transmit Diversity Scheme Based on Water-filling

    Institute of Scientific and Technical Information of China (English)

    SHENCong; DAILin; ZHOUShidong; YAOYan

    2004-01-01

    In this paper we propose a novel bandwidth efficient transmit diversity scheme based on layered space-time architecture, in which Channel state information (CSI) is fully utilized to maximize channel capacity according to water-filling principle. It is shown that compared with V-BLAST, this new scheme can maintain the same high bandwidth efficiency, but achieve much better performance thanks to more effective transmission power allocation and diversity gain.

  8. DIFFERENCE SCHEME AND NUMERICAL SIMULATION BASED ON MIXED FINITE ELEMENT METHOD FOR NATURAL CONVECTION PROBLEM

    Institute of Scientific and Technical Information of China (English)

    罗振东; 朱江; 谢正辉; 张桂芳

    2003-01-01

    The non-stationary natural convection problem is studied. A lowest order finite difference scheme based on mixed finite element method for non-stationary natural convection problem, by the spatial variations discreted with finite element method and time with finite difference scheme was derived, where the numerical solution of velocity, pressure, and temperature can be found together, and a numerical example to simulate the close square cavity is given, which is of practical importance.

  9. Finite volume schemes for multi-dimensional hyperbolic systems based on the use of bicharacteristics

    OpenAIRE

    Lukácová-Medvid'ová, Maria; Saibertova, Jitka

    2004-01-01

    In this paper we present recent results for the bicharacteristic based finite volume schemes, the so-called finite volume evolution Galerkin (FVEG) schemes. These methods were proposed to solve multi-dimensional hyperbolic conservation laws. They combine the usually conflicting design objectives of using the conservation form and following the characteristics, or bicharacteristics. This is realized by combining the finite volume formulation with approximate evolution operators, which use bich...

  10. Finite volume schemes for multidimensional hyperbolic systems based on the use of bicharacteristics

    OpenAIRE

    Lukácová-Medvid'ová, Maria

    2003-01-01

    In this survey paper we present an overview on recent results for the bicharacteristics based finite volume schemes, the so-called finite volume evolution Galerkin (FVEG) schemes. These methods were proposed to solve multidimensional hyperbolic conservation laws. They combine the usually conflicting design objectives of using the conservation form and following the characteritics, or bicharacteritics. This is realized by combining the finite volume formulation with approximate evolution opera...

  11. Provable Data Possession Scheme based on Homomorphic Hash Function in Cloud Storage

    Directory of Open Access Journals (Sweden)

    Li Yu

    2016-01-01

    Full Text Available Cloud storage can satisfy the demand of accessing data at anytime, anyplace. In cloud storage, only when the users can verify that the cloud storage server possesses the data correctly, users shall feel relax to use cloud storage. Provable data possession(PDP makes it easy for a third party to verify whether the data is integrity in the cloud storage server. We analyze the existing PDP schemes, find that these schemes have some drawbacks, such as computationally expensive, only performing a limited number provable data possession. This paper proposes a provable data possession scheme based on homomorphic hash function according to the problems exist in the existing algorithms. The advantage of homomorphic hash function is that it provides provable data possession and data integrity protection. The scheme is a good way to ensure the integrity of remote data and reduce redundant storage space and bandwidth consumption on the premise that users do not retrieve data. The main cost of the scheme is in the server side, it is suitable for mobile devices in the cloud storage environments. We prove that the scheme is feasible by analyzing the security and performance of the scheme.

  12. Security analysis of a chaotic map-based authentication scheme for telecare medicine information systems.

    Science.gov (United States)

    Yau, Wei-Chuen; Phan, Raphael C-W

    2013-12-01

    Many authentication schemes have been proposed for telecare medicine information systems (TMIS) to ensure the privacy, integrity, and availability of patient records. These schemes are crucial for TMIS systems because otherwise patients' medical records become susceptible to tampering thus hampering diagnosis or private medical conditions of patients could be disclosed to parties who do not have a right to access such information. Very recently, Hao et al. proposed a chaotic map-based authentication scheme for telecare medicine information systems in a recent issue of Journal of Medical Systems. They claimed that the authentication scheme can withstand various attacks and it is secure to be used in TMIS. In this paper, we show that this authentication scheme is vulnerable to key-compromise impersonation attacks, off-line password guessing attacks upon compromising of a smart card, and parallel session attacks. We also exploit weaknesses in the password change phase of the scheme to mount a denial-of-service attack. Our results show that this scheme cannot be used to provide security in a telecare medicine information system.

  13. A chaos-based quantum group signature scheme in quantum cryptosystem

    Institute of Scientific and Technical Information of China (English)

    娄小平; 陈志刚; MoonHoLee

    2015-01-01

    A quantum group signature (QGS) scheme is proposed on the basis of an improved quantum chaotic encryption algorithm using the quantum one-time pad with a chaotic operation string. It involves a small-scale quantum computation network in three phases, i.e. initializing phase, signing phase and verifying phase. In the scheme, a member of the group signs the message on behalf of the group while the receiver verifies the signature’s validity with the aid of the trusty group manager who plays a crucial role when a possible dispute arises. Analysis result shows that the signature can neither be forged nor disavowed by any malicious attackers.

  14. Bernoulli-based random undersampling schemes for 2D seismic data regularization

    Institute of Scientific and Technical Information of China (English)

    Cai Rui; Zhao Qun; She De-Ping; Yang Li; Cao Hui; Yang Qin-Yong

    2014-01-01

    Seismic data regularization is an important preprocessing step in seismic signal processing. Traditional seismic acquisition methods follow the Shannon-Nyquist sampling theorem, whereas compressive sensing (CS) provides a fundamentally new paradigm to overcome limitations in data acquisition. Besides the sparse representation of seismic signal in some transform domain and the 1-norm reconstruction algorithm, the seismic data regularization quality of CS-based techniques strongly depends on random undersampling schemes. For 2D seismic data, discrete uniform-based methods have been investigated, where some seismic traces are randomly sampled with an equal probability. However, in theory and practice, some seismic traces with different probability are required to be sampled for satisfying the assumptions in CS. Therefore, designing new undersampling schemes is imperative. We propose a Bernoulli-based random undersampling scheme and its jittered version to determine the regular traces that are randomly sampled with different probability, while both schemes comply with the Bernoulli process distribution. We performed experiments using the Fourier and curvelet transforms and the spectral projected gradient reconstruction algorithm for 1-norm (SPGL1), and ten different random seeds. According to the signal-to-noise ratio (SNR) between the original and reconstructed seismic data, the detailed experimental results from 2D numerical and physical simulation data show that the proposed novel schemes perform overall better than the discrete uniform schemes.

  15. PLS-based memory control scheme for enhanced process monitoring

    KAUST Repository

    Harrou, Fouzi

    2017-01-20

    Fault detection is important for safe operation of various modern engineering systems. Partial least square (PLS) has been widely used in monitoring highly correlated process variables. Conventional PLS-based methods, nevertheless, often fail to detect incipient faults. In this paper, we develop new PLS-based monitoring chart, combining PLS with multivariate memory control chart, the multivariate exponentially weighted moving average (MEWMA) monitoring chart. The MEWMA are sensitive to incipient faults in the process mean, which significantly improves the performance of PLS methods and widen their applicability in practice. Using simulated distillation column data, we demonstrate that the proposed PLS-based MEWMA control chart is more effective in detecting incipient fault in the mean of the multivariate process variables, and outperform the conventional PLS-based monitoring charts.

  16. Route Challenging Scheme Using Friend Based Rating in MANETs

    Directory of Open Access Journals (Sweden)

    S. Shantha Meena

    2013-04-01

    Full Text Available Security and Route identification are the major challenges in MANETs. Existing neighbour based routing algorithms provide route based on the quantity of data transferred [1] which may result in congestion. This is because the route having higher amount of transaction is preferred every time. In this paper we propose a Friend Based Routing algorithm [FBRA] for solving this problem. Here, the appropriate route is found not only based on the quantity of data transferred but also considers RSS and RTT. For providing re-authentication to the nodes in the network, FBRA uses Zero-Knowledge Protocol. The main advantage of this method is providing enhanced security and distinguishes the malicious nodes from the trusted nodes in the network.

  17. Ensemble-based Malware Detection with Different Voting Schemes

    Directory of Open Access Journals (Sweden)

    Ms. Jyoti H. Landage

    2014-10-01

    Full Text Available Now a day’s computer security is the field which attempts to keep information on the computer safe and secure. Security means permitting things you do want, while preventing things you don’t want from happening. Malware represents a serious threat to security of computer system. Traditional anti-malware products use the signature-based, heuristic-based detection techniques to detect the malware. These techniques detect the known malware accurately but can’t detect the new, unknown malware. This paper presents a malware detection system based on the data mining and machine learning technique. The proposed method consists of disassemble process, feature extraction process and feature selection process. Three classification algorithms are employed on dataset to generate and train the classifiers named as Ripper, C4.5, IBk. The ensemble method Voting is used to improve the accuracy of results. Here majority voting and veto voting are implemented; the expected output is decided on the basis of majority and veto voting. The decision strategy of veto is improved by introducing the trust-based veto voting. The results of majority voting, veto voting and trust-based veto voting are compared. The experimental results show that the trust-based veto voting can accurately detect known and unknown malware instances better than majority voting and can identify the benign files better than veto voting.

  18. ENSEMBLE-BASED MALWARE DETECTION WITH DIFFERENT VOTING SCHEMES

    Directory of Open Access Journals (Sweden)

    Jyoti H. Landage

    2015-10-01

    Full Text Available Now a day’s computer security is the field which attempts to keep information on the computer safe and secure. Security means permitting things you do want, while preventing things you don't want from happening. Malware represents a serious threat to security of computer system. Traditional anti-malware products use the signature-based, heuristic-based detection techniques to detect the malware. These techniques detect the known malware accurately but can't detect the new, unknown malware. This paper presents a malware detection system based on the data mining and machine learning technique. The proposed method consists of disassemble process, feature extraction process and feature selection process. Three classification algorithms are employed on dataset to generate and train the classifiers named as Ripper, C4.5, IBk. The ensemble method Voting is used to improve the accuracy of results. Here majority voting and veto voting are implemented; the expected output is decided on the basis of majority and veto voting. The decision strategy of veto is improved by introducing the trust-based veto voting. The results of majority voting, veto voting and trust-based veto voting are compared. The experimental results show that the trust-based veto voting can accurately detect known and unknown malware instances better than majority voting and can identify the benign files better than veto voting.

  19. A learning scheme for reach to grasp movements: on EMG-based interfaces using task specific motion decoding models.

    Science.gov (United States)

    Liarokapis, Minas V; Artemiadis, Panagiotis K; Kyriakopoulos, Kostas J; Manolakos, Elias S

    2013-09-01

    A learning scheme based on random forests is used to discriminate between different reach to grasp movements in 3-D space, based on the myoelectric activity of human muscles of the upper-arm and the forearm. Task specificity for motion decoding is introduced in two different levels: Subspace to move toward and object to be grasped. The discrimination between the different reach to grasp strategies is accomplished with machine learning techniques for classification. The classification decision is then used in order to trigger an EMG-based task-specific motion decoding model. Task specific models manage to outperform "general" models providing better estimation accuracy. Thus, the proposed scheme takes advantage of a framework incorporating both a classifier and a regressor that cooperate advantageously in order to split the task space. The proposed learning scheme can be easily used to a series of EMG-based interfaces that must operate in real time, providing data-driven capabilities for multiclass problems, that occur in everyday life complex environments.

  20. Proxy-Based IPv6 Neighbor Discovery Scheme for Wireless LAN Based Mesh Networks

    Science.gov (United States)

    Lee, Jihoon; Jeon, Seungwoo; Kim, Jaehoon

    Multi-hop Wireless LAN-based mesh network (WMN) provides high capacity and self-configuring capabilities. Due to data forwarding and path selection based on MAC address, WMN requires additional operations to achieve global connectivity using IPv6 address. The neighbor discovery operation over WLAN mesh networks requires repeated all-node broadcasting and this gives rise to a big burden in the entire mesh networks. In this letter, we propose the proxy neighbor discovery scheme for optimized IPv6 communication over WMN to reduce network overhead and communication latency. Using simulation experiments, we show that the control overhead and communication setup latency can be significantly reduced using the proxy-based neighbor discovery mechanism.

  1. A Distributed Cluster Scheme For Bandwidth Management In Multi-hop MANETs

    CERN Document Server

    Pattanayak, Binod Kumar; Mishra, Manoj Kumar; Nayak, Manoj Ranjan

    2010-01-01

    Electronic collaboration among devices in a geographically localized environment is made possible with the implementation of IEEE 802.11 based wireless ad hoc networks. Dynamic nature of mobile ad hoc networks(MANETs) may lead to unpredictable intervention of attacks or fault occurrence, which consequently may partition the network, degrade its performance, violate the QoS requirements and most importantly, affect bandwidth allocation to mobile nodes in the network. In this paper, we propose a new distributed cluster scheme for MANETs, especially in harsh environments, based on the concept of survivability to support QoS requirements and to protect bandwidth efficiently. With the incorporation of clustering algorithms in survivability technology, we employ a simple network configuration and expect to reduce occurrences of faults in MANETs. At the same time, we address the scalability problem, which represents a great challenge to network configuration. We do expect a simplification of accessing bandwidth allo...

  2. Evaluation of frame aggregation schemes for the p-persistent based next generation WLANS

    Science.gov (United States)

    Ahmad, Ashar; Anna, Kiran; Bassiouni, Mostafa A.

    2010-04-01

    The next Generation IEEE 802.11n is designed to improve the throughput of the existing standard 802.11. It aims to achieve this by increasing the data rate from 54 Mbps to 600 Mbps with the help of physical layer enhancements. Therefore, the Medium Access Layer (MAC) requires improvements to fully utilize the capabilities of the enhanced 802.11n physical layer. In this paper, we present the performance evaluation results of two frame aggregation schemes viz., MAC Protocol Data Unit Aggregation (A-MPDU) and MAC Service Data Unit Aggregation (A-MSDU) and study their performance impact when the two schemes are incorporated in a p-persistent based 802.11n. The simulation results have shown that the two schemes achieve consistent performance improvement over the standard non-aggregation scheme.

  3. An Image Encryption Scheme Based on Bit Circular Shift and Bi-directional Diffusion

    Directory of Open Access Journals (Sweden)

    Ruisong Ye

    2013-12-01

    Full Text Available A novel image encryption scheme based on chaotic system is proposed. The proposed encryption scheme utilizes one tent map to generate a pseudo-random sequence and then shift the bits of the expanding 0-1 image circularly so as to shuffle the image gray values. To make the encryption scheme resist differential attack efficiently, generalized Arnold maps and Bernoulli shift maps are applied to produce two pseudo-random gray value sequences and then diffuse the gray values bi-directionally. The bit circular shift process and diffusion processes greatly confuse the statistical nature between plain-images and cipher-images. Security analyses including key sensitivity analysis, key space analysis, statistical analysis, differential attack analysis and information entropy analysis are performed. All the experimental results demonstrate that the proposed image encryption scheme possesses large key space to frustrate brute-force attack efficiently and can resist statistical attack, differential attack, etc.

  4. A Quantum Multi-Proxy Weak Blind Signature Scheme Based on Entanglement Swapping

    Science.gov (United States)

    Yan, LiLi; Chang, Yan; Zhang, ShiBin; Han, GuiHua; Sheng, ZhiWei

    2016-11-01

    In this paper, we present a multi-proxy weak blind signature scheme based on quantum entanglement swapping of Bell states. In the scheme, proxy signers can finish the signature instead of original singer with his/her authority. It can be applied to the electronic voting system, electronic paying system, etc. The scheme uses the physical characteristics of quantum mechanics to implement delegation, signature and verification. It could guarantee not only the unconditionally security but also the anonymity of the message owner. The security analysis shows the scheme satisfies the security features of multi-proxy weak signature, singers cannot disavowal his/her signature while the signature cannot be forged by others, and the message owner can be traced.

  5. Novel UEP LT Coding Scheme with Feedback Based on Different Degree Distributions

    Directory of Open Access Journals (Sweden)

    Li Ya-Fang

    2016-01-01

    Full Text Available Traditional unequal error protection (UEP schemes have some limitations and problems, such as the poor UEP performance of high priority data and the seriously sacrifice of low priority data in decoding property. Based on the reasonable applications of different degree distributions in LT codes, this paper puts forward a novel UEP LT coding scheme with a simple feedback to compile these data packets separately. Simulation results show that the proposed scheme can effectively protect high priority data, and improve the transmission efficiency of low priority data from 2.9% to 22.3%. Furthermore, it is fairly suitable to apply this novel scheme to multicast and broadcast environments since only a simple feedback introduced.

  6. Experimental Investigation of Cooperative Schemes on a Real-Time DSP-Based Testbed

    Directory of Open Access Journals (Sweden)

    Per Zetterberg

    2009-01-01

    Full Text Available Experimental results on the well-known cooperating relaying schemes, amplify-and-forward (AF, detect-and-forward (DF, cooperative maximum ratio combining (CMRC, and distributed space-time coding (DSTC, are presented in this paper. A novel relaying scheme named “selection relaying” (SR, in which one of two relays are selected base on path-loss, is also tested. For all schemes except AF receive antenna diversity is as an option which can be switched on or off. For DF and DSTC a feature “selective” where the relay only forwards frames with a receive SNR above 6 dB is introduced. In our measurements, all cooperative relaying schemes above increase the coverage area as compared with direct transmission. The features “antenna diversity” and “selective” improve the performance. Good performance is obtained with CMRC, DSTC, and SR.

  7. Threshold Cryptography-based Group Authentication (TCGA) Scheme for the Internet of Things (IoT)

    DEFF Research Database (Denmark)

    Mahalle, Parikshit N.; Prasad, Neeli R.; Prasad, Ramjee

    2014-01-01

    , and receipt of their authentication request at the same time. Therefore, secure, and efficient group authentication, and authorization scheme is required that authenticates a group of devices at once in the context of resource constrained IoT. This paper presents novel Threshold Cryptography-based Group...... Authentication (TCGA) scheme for the IoT which verifies authenticity of all the devices taking part in the group communication. This paper also presents TCGA framework which is flexible and secure. The proposed TCGA scheme is implemented for WI-FI environment, and the result shows that TCGA scheme is lightweight......Internet of things (IoT) is an emerging paradigm where the devices around us (persistent and non-persistent) are connected to each other to provide seamless communication, and contextual services. In the IoT, each device cannot be authenticated in the short time due to unbounded number of devices...

  8. On the security of a dynamic ID-based authentication scheme for telecare medical information systems.

    Science.gov (United States)

    Lin, Han-Yu

    2013-04-01

    Telecare medical information systems (TMISs) are increasingly popular technologies for healthcare applications. Using TMISs, physicians and caregivers can monitor the vital signs of patients remotely. Since the database of TMISs stores patients' electronic medical records (EMRs), only authorized users should be granted the access to this information for the privacy concern. To keep the user anonymity, recently, Chen et al. proposed a dynamic ID-based authentication scheme for telecare medical information system. They claimed that their scheme is more secure and robust for use in a TMIS. However, we will demonstrate that their scheme fails to satisfy the user anonymity due to the dictionary attacks. It is also possible to derive a user password in case of smart card loss attacks. Additionally, an improved scheme eliminating these weaknesses is also presented.

  9. Protection of Health Imagery by Region Based Lossless Reversible Watermarking Scheme

    Directory of Open Access Journals (Sweden)

    R. Lakshmi Priya

    2015-01-01

    Full Text Available Providing authentication and integrity in medical images is a problem and this work proposes a new blind fragile region based lossless reversible watermarking technique to improve trustworthiness of medical images. The proposed technique embeds the watermark using a reversible least significant bit embedding scheme. The scheme combines hashing, compression, and digital signature techniques to create a content dependent watermark making use of compressed region of interest (ROI for recovery of ROI as reported in literature. The experiments were carried out to prove the performance of the scheme and its assessment reveals that ROI is extracted in an intact manner and PSNR values obtained lead to realization that the presented scheme offers greater protection for health imageries.

  10. Protection of Health Imagery by Region Based Lossless Reversible Watermarking Scheme.

    Science.gov (United States)

    Priya, R Lakshmi; Sadasivam, V

    2015-01-01

    Providing authentication and integrity in medical images is a problem and this work proposes a new blind fragile region based lossless reversible watermarking technique to improve trustworthiness of medical images. The proposed technique embeds the watermark using a reversible least significant bit embedding scheme. The scheme combines hashing, compression, and digital signature techniques to create a content dependent watermark making use of compressed region of interest (ROI) for recovery of ROI as reported in literature. The experiments were carried out to prove the performance of the scheme and its assessment reveals that ROI is extracted in an intact manner and PSNR values obtained lead to realization that the presented scheme offers greater protection for health imageries.

  11. Efficient Relay Selection Scheme based on Fuzzy Logic for Cooperative Communication

    Directory of Open Access Journals (Sweden)

    Shakeel Ahmad Waqas

    2016-11-01

    Full Text Available The performance of cooperative network can be increased by using relay selection technique. Therefore, interest in relay selection is sloping upward. We proposed two new relay selection schemes based on fuzzy logic for dual hop cooperative communication. These relay selection schemes require SNR (signal to noise ratio, cooperative gain and channel gain as input fuzzy parameters for selection of best relay. The performance of first proposed relay selection scheme is evaluated in term of BER (bit error rate in Nakagami, Rician and Rayleigh fading channels. In second proposed relay selection scheme, threshold is used with the objective to minimize the power consumption and channel estimation load. Its performance is analyzed in term of BER, number of active relays and load of number of channel estimations.

  12. A DELAY BASED BACKOFF SCHEME FOR WLAN WITH QoS GUARANTEE AND ITS PERFORMANCE

    Institute of Scientific and Technical Information of China (English)

    Li Xiaohui; Kou Weidong; Liu Nai'an; Yi Kechu

    2005-01-01

    Based on the Distributed Coordination Function (DCF) and the Enhanced DCF (EDCF) mechanisms in IEEE 802.11 and 802.11e, a novel backoff scheme for Wireless Local Area Network (WLAN) is proposed. The scheme is to solve the problem of the packet loss and the decrease of performance due to the increasing Contention Window (CW) when there are continuous collisions. In the proposed scheme, the CW of the packet will change dynamically with different delay for the different traffics. Mathematic formulas are presented to indicate the relationship between the CW and the delay character. ,The performance of the new scheme is also discussed with simulation results. The results show that it helps WLAN system handle multimedia simultaneously.

  13. Cryptanalysis and Improvement of Selvi et al.’s Identity-Based Threshold Signcryption Scheme

    Directory of Open Access Journals (Sweden)

    Wei Yuan

    2011-11-01

    Full Text Available Signcryption can realize the function of encryption and signature in a reasonable logic step, which can lower computational costs and communication overheads. In 2008, S. S. D. Selvi et al. proposed an identity-based threshold signcryption scheme. In this paper, we show that the threshold signcryption scheme of S. S. D. Selvi et al. is vulnerable if the attacker can replaces the group public key. Then we point out that the receiver uses the senders’ public key without any verification in the unsigncrypt stage cause this attack. Further, we propose a probably-secure improved scheme to correct the vulnerable and give the unforgeability and confidentiality of our improved scheme under the existing security assumption.

  14. Highly Robust and Imperceptible Luminance Based Hybrid Digital Video Watermarking Scheme for Ownership Protection

    Directory of Open Access Journals (Sweden)

    Himanshu Agarwal

    2012-10-01

    Full Text Available In this paper a hybrid digital video watermarking scheme based on discrete wavelet transform and singular value decomposition is proposed. Unlike the most existing watermarking schemes, the used watermark is a gray scale image instead of a binary watermark. The watermark is embedded in the original video frames by first converted it into YCbCr color space and than decomposing the luminance part (Y component into four sub-bands using discrete wavelet transform and finally the singular values of LL sub-band are shaped perceptually by singular values of watermark image. The experimental result shows a tradeoff between imperceptibility and resiliency against intentional attacks such as rotation, cropping, histogram stretching, JPEG compression on individual frames, Indeo5 video compression and unintentional attacks like frame swapping, frame averaging, frame insertion and different types of noise addition. Superiority of the proposed scheme is carried out by comparison with existing schemes to reveal its efficiency for practical applications.

  15. Advanced neural network-based computational schemes for robust fault diagnosis

    CERN Document Server

    Mrugalski, Marcin

    2014-01-01

    The present book is devoted to problems of adaptation of artificial neural networks to robust fault diagnosis schemes. It presents neural networks-based modelling and estimation techniques used for designing robust fault diagnosis schemes for non-linear dynamic systems. A part of the book focuses on fundamental issues such as architectures of dynamic neural networks, methods for designing of neural networks and fault diagnosis schemes as well as the importance of robustness. The book is of a tutorial value and can be perceived as a good starting point for the new-comers to this field. The book is also devoted to advanced schemes of description of neural model uncertainty. In particular, the methods of computation of neural networks uncertainty with robust parameter estimation are presented. Moreover, a novel approach for system identification with the state-space GMDH neural network is delivered. All the concepts described in this book are illustrated by both simple academic illustrative examples and practica...

  16. A bilinear pairing based anonymous authentication scheme in wireless body area networks for mHealth.

    Science.gov (United States)

    Jiang, Qi; Lian, Xinxin; Yang, Chao; Ma, Jianfeng; Tian, Youliang; Yang, Yuanyuan

    2016-11-01

    Wireless body area networks (WBANs) have become one of the key components of mobile health (mHealth) which provides 24/7 health monitoring service and greatly improves the quality and efficiency of healthcare. However, users' concern about the security and privacy of their health information has become one of the major obstacles that impede the wide adoption of WBANs. Anonymous and unlinkable authentication is critical to protect the security and privacy of sensitive physiological information in transit from the client to the application provider. We first show that the anonymous authentication scheme of Wang and Zhang based on bilinear pairing is prone to client impersonation attack. Then, we propose an enhanced anonymous authentication scheme to remedy the flaw in Wang and Zhang's scheme. We give the security analysis to demonstrate that the enhanced scheme achieves the desired security features and withstands various known attacks.

  17. Improvement of a quantum broadcasting multiple blind signature scheme based on quantum teleportation

    Science.gov (United States)

    Zhang, Wei; Qiu, Daowen; Zou, Xiangfu

    2016-06-01

    Recently, a broadcasting multiple blind signature scheme based on quantum teleportation has been proposed for the first time. It is claimed to have unconditional security and properties of quantum multiple signature and quantum blind signature. In this paper, we analyze the security of the protocol and show that each signatory can learn the signed message by a single-particle measurement and the signed message can be modified at random by any attacker according to the scheme. Furthermore, there are some participant attacks and external attacks existing in the scheme. Finally, we present an improved scheme and show that it can resist all of the mentioned attacks. Additionally, the secret keys can be used again and again, making it more efficient and practical.

  18. an Efficient Blind Signature Scheme based on Error Correcting Codes

    Directory of Open Access Journals (Sweden)

    Junyao Ye

    Full Text Available Cryptography based on the theory of error correcting codes and lattices has received a wide attention in the last years. Shor`s algorithm showed that in a world where quantum computers are assumed to exist, number theoretic cryptosystems are insecure. The ...

  19. Control charts for location based on different sampling schemes

    NARCIS (Netherlands)

    Mehmood, R.; Riaz, M.; Does, R.J.M.M.

    2013-01-01

    Control charts are the most important statistical process control tool for monitoring variations in a process. A number of articles are available in the literature for the X̄ control chart based on simple random sampling, ranked set sampling, median-ranked set sampling (MRSS), extreme-ranked set

  20. Cache Scheme Based on Pre-Fetch Operation in ICN.

    Directory of Open Access Journals (Sweden)

    Jie Duan

    Full Text Available Many recent researches focus on ICN (Information-Centric Network, in which named content becomes the first citizen instead of end-host. In ICN, Named content can be further divided into many small sized chunks, and chunk-based communication has merits over content-based communication. The universal in-network cache is one of the fundamental infrastructures for ICN. In this work, a chunk-level cache mechanism based on pre-fetch operation is proposed. The main idea is that, routers with cache store should pre-fetch and cache the next chunks which may be accessed in the near future according to received requests and cache policy for reducing the users' perceived latency. Two pre-fetch driven modes are present to answer when and how to pre-fetch. The LRU (Least Recently Used is employed for the cache replacement. Simulation results show that the average user perceived latency and hops can be decreased by employed this cache mechanism based on pre-fetch operation. Furthermore, we also demonstrate that the results are influenced by many factors, such as the cache capacity, Zipf parameters and pre-fetch window size.

  1. Cutting Tools. Youth Training Scheme. Core Exemplar Work Based Project.

    Science.gov (United States)

    Further Education Staff Coll., Blagdon (England).

    This trainer's guide is intended to assist supervisors of work-based career training projects in teaching students to compare the performance of two different types of engineering cutting tools and to determine their cost-effectiveness and efficiency. The guide is one in a series of core curriculum modules that is intended for use in combination…

  2. A General Threshold Signature and Authenticated Encryption Scheme Based on ElGamal System

    Directory of Open Access Journals (Sweden)

    Yulian Shang

    2013-07-01

    Full Text Available Based on ElGamal system, a group-oriented threshold signature and authenticated encryption scheme was put forward. After being signed by a signer group employing threshold signature scheme, the message was transmitted to a particular verifier group, and then the signature was verified through the cooperation of  ones from the verifier group with  members. Similarly, a general authenticated encryption scheme characterized by joint verification was put forward through integrating threshold signature scheme and message recovery technique together; After being encrypted singed by any  ones from a group with  members, the message was transmitted to a particular verifier group with members, and then recovered through the cooperation of any ones from the verifier group. The security of this scheme is based on Shamir threshold scheme and ElGamal system. It realized the directional transmission of message between different groups and enjoyed the characteristics of reduced communication load and lowered calculation complexity, etc.

  3. TripSense: A Trust-Based Vehicular Platoon Crowdsensing Scheme with Privacy Preservation in VANETs.

    Science.gov (United States)

    Hu, Hao; Lu, Rongxing; Huang, Cheng; Zhang, Zonghua

    2016-06-01

    In this paper, we propose a trust-based vehicular platoon crowdsensing scheme, named TripSense, in VANET. The proposed TripSense scheme introduces a trust-based system to evaluate vehicles' sensing abilities and then selects the more capable vehicles in order to improve sensing results accuracy. In addition, the sensing tasks are accomplished by platoon member vehicles and preprocessed by platoon head vehicles before the data are uploaded to server. Hence, it is less time-consuming and more efficient compared with the way where the data are submitted by individual platoon member vehicles. Hence it is more suitable in ephemeral networks like VANET. Moreover, our proposed TripSense scheme integrates unlinkable pseudo-ID techniques to achieve PM vehicle identity privacy, and employs a privacy-preserving sensing vehicle selection scheme without involving the PM vehicle's trust score to keep its location privacy. Detailed security analysis shows that our proposed TripSense scheme not only achieves desirable privacy requirements but also resists against attacks launched by adversaries. In addition, extensive simulations are conducted to show the correctness and effectiveness of our proposed scheme.

  4. A biometric signcryption scheme without bilinear pairing

    Science.gov (United States)

    Wang, Mingwen; Ren, Zhiyuan; Cai, Jun; Zheng, Wentao

    2013-03-01

    How to apply the entropy in biometrics into the encryption and remote authentication schemes to simplify the management of keys is a hot research area. Utilizing Dodis's fuzzy extractor method and Liu's original signcryption scheme, a biometric identity based signcryption scheme is proposed in this paper. The proposed scheme is more efficient than most of the previous proposed biometric signcryption schemes for that it does not need bilinear pairing computation and modular exponentiation computation which is time consuming largely. The analysis results show that under the CDH and DL hard problem assumption, the proposed scheme has the features of confidentiality and unforgeability simultaneously.

  5. Evaluation of Effectiveness of Wavelet Based Denoising Schemes Using ANN and SVM for Bearing Condition Classification

    Directory of Open Access Journals (Sweden)

    Vijay G. S.

    2012-01-01

    Full Text Available The wavelet based denoising has proven its ability to denoise the bearing vibration signals by improving the signal-to-noise ratio (SNR and reducing the root-mean-square error (RMSE. In this paper seven wavelet based denoising schemes have been evaluated based on the performance of the Artificial Neural Network (ANN and the Support Vector Machine (SVM, for the bearing condition classification. The work consists of two parts, the first part in which a synthetic signal simulating the defective bearing vibration signal with Gaussian noise was subjected to these denoising schemes. The best scheme based on the SNR and the RMSE was identified. In the second part, the vibration signals collected from a customized Rolling Element Bearing (REB test rig for four bearing conditions were subjected to these denoising schemes. Several time and frequency domain features were extracted from the denoised signals, out of which a few sensitive features were selected using the Fisher’s Criterion (FC. Extracted features were used to train and test the ANN and the SVM. The best denoising scheme identified, based on the classification performances of the ANN and the SVM, was found to be the same as the one obtained using the synthetic signal.

  6. [Extension of health coverage and community based health insurance schemes in Africa: Myths and realities].

    Science.gov (United States)

    Boidin, B

    2015-02-01

    This article tackles the perspectives and limits of the extension of health coverage based on community based health insurance schemes in Africa. Despite their strong potential contribution to the extension of health coverage, their weaknesses challenge their ability to play an important role in this extension. Three limits are distinguished: financial fragility; insufficient adaptation to characteristics and needs of poor people; organizational and institutional failures. Therefore lessons can be learnt from the limits of the institutionalization of community based health insurance schemes. At first, community based health insurance schemes are to be considered as a transitional but insufficient solution. There is also a stronger role to be played by public actors in improving financial support, strengthening health services and coordinating coverage programs.

  7. A novel lost packets recovery scheme based on visual secret sharing

    Science.gov (United States)

    Lu, Kun; Shan, Hong; Li, Zhi; Niu, Zhao

    2017-08-01

    In this paper, a novel lost packets recovery scheme which encrypts the effective parts of an original packet into two shadow packets based on (2, 2)-threshold XOR-based visual Secret Sharing (VSS) is proposed. The two shadow packets used as watermarks would be embedded into two normal data packets with digital watermarking embedding technology and then sent from one sensor node to another. Each shadow packet would reveal no information of the original packet, which can improve the security of original packet delivery greatly. The two shadow packets which can be extracted from the received two normal data packets delivered from a sensor node can recover the original packet lossless based on XOR-based VSS. The Performance analysis present that the proposed scheme provides essential services as long as possible in the presence of selective forwarding attack. The proposed scheme would not increase the amount of additional traffic, namely, lower energy consumption, which is suitable for Wireless Sensor Network (WSN).

  8. A Comparison Study on Selective Traffic Models with Handoff Management Scheme for Wireless Mobile Network Infrastructure

    Directory of Open Access Journals (Sweden)

    Biswajit Bhowmik

    2013-01-01

    Full Text Available Wireless and Mobile Network Infrastructure services generally examine how different infrastructure providers are positioning themselves to compete in wireless services. These services analyze the opportunities and challenges facing by the infrastructure providers selling to wireless and mobile network operators worldwide. The opportunities and challenges are the review of strategies, market positioning, and future direction in the market for wireless and mobile network infrastructure. The service covers all generations of wireless and mobile network infrastructure: 2G, 2.5G, 3G, and 4G so on global in scope. Majority of the users are mobile while availing these services. Mobility is the most important feature of any wireless and mobile network. Usually, continuous service is achieved by supporting handoff from one cell to another. Poorly designed handoff schemes tend to generate very heavy signaling traffic and, thereby, lead to a dramatic decrease in quality of service. In this paper we make a comparison study on some selective traffic models with priority handoff scheme. The study shows how a handoff procedure has a significant impact on wireless mobile network performance on the basis of two primary criteria – Blocking probability of originating calls and the forced termination probability of ongoing calls. In addition to this the study shows arrival rate of handoff calls, and approximate number of mobile users that get serviced by underlying base station.

  9. Predictors of Availing Maternal Health Schemes: A community based study in Gujarat, India

    Directory of Open Access Journals (Sweden)

    Kranti Suresh Vora

    2014-06-01

    Full Text Available Background: India continues to face challenges in improving key maternal health indicators with about 1/3rd of global maternal deaths happening in India. Utilization of health care services is an important issue in India with significant proportion of home deliveries and majority of mothers not receiving adequate antenatal care. Mortality among poor rural women is the highest with lowest utilization. To make maternal healthcare more equitable, numerous schemes such as Janani Suraksha Yojana, Chiranjeevi Yojana, Kasturba Poshan Sahay Yojana have been introduced. Studies suggest that utilization of such schemes by target population is low and there is a need to understand factors affecting maternal health care utilization in the context of these schemes. Current community based study was done in rural Gujarat to understand characteristics of women who utilize such schemes and predictors of utilization. Methodology: Data collection was done in two districts of Gujarat from June to August, 2013 as a pilot phase of MATIND project. Community based cross-sectional study included 827 households and socio-demographic details of 1454 women of 15-49 years age groups were collected. 265 mothers, who had delivered after 1st January, 2013 are included in the regression analyses. The data analysis carried out with R version 3.0.1 software.  Results: The analysis indicates socioeconomic variables such as caste, maternal variables such as education and health system variables such as use of government facility are important predictors of maternal health scheme utilization. Results suggest that socioeconomic and health system factors are the best predictors for availing scheme. Conclusion: Health system variables along with individual level variables are important predictors for availing maternal health schemes. The study indicates the need to examine all levels of predictors for utilizing government health schemes to maximize the benefit for underserved

  10. ADAPTATIVE IMAGE WATERMARKING SCHEME BASED ON NEURAL NETWORK

    Directory of Open Access Journals (Sweden)

    BASSEL SOLAIMANE

    2011-01-01

    Full Text Available Digital image watermarking has been proposed as a method to enhance medical data security, confidentiality and integrity. Medical image watermarking requires extreme care when embedding additional data, given their importance to clinical diagnosis, treatment, and research. In this paper, a novel image watermarking approach based on the human visual system (HVS model and neural network technique is proposed. The watermark was inserted into the middle frequency coefficients of the cover image’s blocked DCT based transform domain. In order to make the watermark stronger and less susceptible to different types of attacks, it is essential to find the maximum amount of interested watermark before the watermark becomes visible. In this paper, neural networks are used to implement an automated system of creating maximum-strength watermarks. The experimental results show that such method can survive of common image processing operations and has good adaptability for automated watermark embedding.

  11. An Improved Wavelet‐Based Multivariable Fault Detection Scheme

    KAUST Repository

    Harrou, Fouzi

    2017-07-06

    Data observed from environmental and engineering processes are usually noisy and correlated in time, which makes the fault detection more difficult as the presence of noise degrades fault detection quality. Multiscale representation of data using wavelets is a powerful feature extraction tool that is well suited to denoising and decorrelating time series data. In this chapter, we combine the advantages of multiscale partial least squares (MSPLSs) modeling with those of the univariate EWMA (exponentially weighted moving average) monitoring chart, which results in an improved fault detection system, especially for detecting small faults in highly correlated, multivariate data. Toward this end, we applied EWMA chart to the output residuals obtained from MSPLS model. It is shown through simulated distillation column data the significant improvement in fault detection can be obtained by using the proposed methods as compared to the use of the conventional partial least square (PLS)‐based Q and EWMA methods and MSPLS‐based Q method.

  12. Delay Scheduling Based Replication Scheme for Hadoop Distributed File System

    Directory of Open Access Journals (Sweden)

    S. Suresh

    2015-03-01

    Full Text Available The data generated and processed by modern computing systems burgeon rapidly. MapReduce is an important programming model for large scale data intensive applications. Hadoop is a popular open source implementation of MapReduce and Google File System (GFS. The scalability and fault-tolerance feature of Hadoop makes it as a standard for BigData processing. Hadoop uses Hadoop Distributed File System (HDFS for storing data. Data reliability and faulttolerance is achieved through replication in HDFS. In this paper, a new technique called Delay Scheduling Based Replication Algorithm (DSBRA is proposed to identify and replicate (dereplicate the popular (unpopular files/blocks in HDFS based on the information collected from the scheduler. Experimental results show that, the proposed method achieves 13% and 7% improvements in response time and locality over existing algorithms respectively.

  13. Analysis of declarations in distance based road toll schemes

    OpenAIRE

    Menzel, Gerhard

    2010-01-01

    The main focus of the master thesis lies on developing a methodology to analyse the accuracy of toll declarations within a satellite based toll system. This methodology employs two different approaches to determine reasons why Toll Service Providers (TSP) deliver toll declarations that show charge inaccuracies. Both approaches are carried out to analyse the results of the ARENA project’s field test which was held in April 2010 to test On Board Unit (OBU) solutions for toll collection. In part...

  14. A quartic B-spline based explicit time integration scheme for structural dynamics with controllable numerical dissipation

    Science.gov (United States)

    Wen, W. B.; Duan, S. Y.; Yan, J.; Ma, Y. B.; Wei, K.; Fang, D. N.

    2017-03-01

    An explicit time integration scheme based on quartic B-splines is presented for solving linear structural dynamics problems. The scheme is of a one-parameter family of schemes where free algorithmic parameter controls stability, accuracy and numerical dispersion. The proposed scheme possesses at least second-order accuracy and at most third-order accuracy. A 2D wave problem is analyzed to demonstrate the effectiveness of the proposed scheme in reducing high-frequency modes and retaining low-frequency modes. Except for general structural dynamics, the proposed scheme can be used effectively for wave propagation problems in which numerical dissipation is needed to reduce spurious oscillations.

  15. A quartic B-spline based explicit time integration scheme for structural dynamics with controllable numerical dissipation

    Science.gov (United States)

    Wen, W. B.; Duan, S. Y.; Yan, J.; Ma, Y. B.; Wei, K.; Fang, D. N.

    2016-11-01

    An explicit time integration scheme based on quartic B-splines is presented for solving linear structural dynamics problems. The scheme is of a one-parameter family of schemes where free algorithmic parameter controls stability, accuracy and numerical dispersion. The proposed scheme possesses at least second-order accuracy and at most third-order accuracy. A 2D wave problem is analyzed to demonstrate the effectiveness of the proposed scheme in reducing high-frequency modes and retaining low-frequency modes. Except for general structural dynamics, the proposed scheme can be used effectively for wave propagation problems in which numerical dissipation is needed to reduce spurious oscillations.

  16. Watermarking Scheme Based on Wavelet Transformation and Visual Cryptography

    Institute of Scientific and Technical Information of China (English)

    Young-Chang Hou; Shih-Chieh Wei; Hsin-Ju Liu; A-Yu Tseng

    2014-01-01

    Based on the principles of the visual cryptography and the law of large numbers, the unexpanded shares are generated during the processes of embedding and verifying the hidden watermark. The watermark embedding is done in the frequency domain, which can be decoded by the human visual system (HVS) without the necessity of any complicated computation and the help of the original image. Experimental results indicated that our method had a good robustness on darkening, lightening, blurring, sharpening, noise, distorting, jitter, joint photographic experts group (JPEG) compression, and crop attacks.

  17. A new iterative speech enhancement scheme based on Kalman filtering

    DEFF Research Database (Denmark)

    Li, Chunjian; Andersen, Søren Vang

    2005-01-01

    Subtraction filter is introduced as an initialization procedure. Iterations are then made sequential inter-frame, exploiting the fact that the AR model changes slowly between neighboring frames. The proposed algorithm is computationally more efficient than a baseline EM algorithm due to its fast convergence...... for a high temporal resolution estimation of this variance. A Local Variance Estimator based on a Prediction Error Kalman Filter is designed for this high temporal resolution variance estimation. To achieve fast convergence and avoid local maxima of the likelihood function, a Weighted Power Spectral...

  18. A Score Based Trustworthy Declaration Scheme For Vanets

    Directory of Open Access Journals (Sweden)

    A.Jenifer Sophia

    2014-03-01

    Full Text Available Vehicles are allowed to generate and broadcast messages about road conditions, such as traffic congestion and accidents to nearby vehicles in Vehicular ad hoc networks (VANETs. These kinds of messages may improve road safety and traffic efficiency of neighboring vehicles. However, messages generated by vehicles may not be reliable. Then propose the secure algorithm through a novel announcement system. The neighboring vehicle utilizes this information within a seconds through the SHA1- RSA algorithm and be aware form the road conditions. The reputation system is to find the evaluation of the reliability of the message is based on the digital score which is stored in the server.

  19. New chaos-based encryption scheme for digital sequence

    Institute of Scientific and Technical Information of China (English)

    Zhang Zhengwei; Fan Yangyu; Zeng Li

    2007-01-01

    To enhance the anti-breaking performance of privacy information, this article proposes a new encryption method utilizing the leaping peculiarity of the periodic orbits of chaos systems. This method maps the secret sequence to several chaos periodic orbits, and a short sequence obtained by evolving the system parameters of the periodic orbits in another nonlinear system will be the key to reconstruct these periodic orbits. In the decryption end, the shadowing method of chaos trajectory based on the modified Newton-Raphson algorithm is adopted to restore these system parameters. Through deciding which orbit each pair coordinate falls on, the original digital sequence can be decrypted.

  20. Efficient and Provable Secure Pairing-Free Security-Mediated Identity-Based Identification Schemes

    Directory of Open Access Journals (Sweden)

    Ji-Jian Chin

    2014-01-01

    Full Text Available Security-mediated cryptography was first introduced by Boneh et al. in 2001. The main motivation behind security-mediated cryptography was the capability to allow instant revocation of a user’s secret key by necessitating the cooperation of a security mediator in any given transaction. Subsequently in 2003, Boneh et al. showed how to convert a RSA-based security-mediated encryption scheme from a traditional public key setting to an identity-based one, where certificates would no longer be required. Following these two pioneering papers, other cryptographic primitives that utilize a security-mediated approach began to surface. However, the security-mediated identity-based identification scheme (SM-IBI was not introduced until Chin et al. in 2013 with a scheme built on bilinear pairings. In this paper, we improve on the efficiency results for SM-IBI schemes by proposing two schemes that are pairing-free and are based on well-studied complexity assumptions: the RSA and discrete logarithm assumptions.