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Sample records for spot pattern encryption

  1. Substring-Searchable Symmetric Encryption

    Directory of Open Access Journals (Sweden)

    Chase Melissa

    2015-06-01

    Full Text Available In this paper, we consider a setting where a client wants to outsource storage of a large amount of private data and then perform substring search queries on the data – given a data string s and a search string p, find all occurrences of p as a substring of s. First, we formalize an encryption paradigm that we call queryable encryption, which generalizes searchable symmetric encryption (SSE and structured encryption. Then, we construct a queryable encryption scheme for substring queries. Our construction uses suffix trees and achieves asymptotic efficiency comparable to that of unencrypted suffix trees. Encryption of a string of length n takes O(λn time and produces a ciphertext of size O(λn, and querying for a substring of length m that occurs k times takes O(λm+k time and three rounds of communication. Our security definition guarantees correctness of query results and privacy of data and queries against a malicious adversary. Following the line of work started by Curtmola et al. (ACM CCS 2006, in order to construct more efficient schemes we allow the query protocol to leak some limited information that is captured precisely in the definition. We prove security of our substring-searchable encryption scheme against malicious adversaries, where the query protocol leaks limited information about memory access patterns through the suffix tree of the encrypted string.

  2. [Study on Hexagonal Super-Lattice Pattern with Light Spot and Dim Spot in Dielectric Barrier Discharge by Optical Emission Spectra].

    Science.gov (United States)

    Liu, Ying; Dong, Li-fang; Niu, Xue-jiao; Zhang, Chao

    2016-02-01

    The hexagonal super-lattice pattern composed of the light spot and the dim spot is firstly observed and investigated in the discharge of gas mixture of air and argon by using the dielectric barrier discharge device with double water electrodes. It is found that the dim spot is located at the center of its surrounding three light spots by observing the discharge image. Obviously, the brightness of the light spot and the dim spot are different, which indicates that the plasma states of the light spot and the dim spot may be different. The optical emission spectrum method is used to further study the several plasma parameters of the light spot and the dim spot in different argon content. The emission spectra of the N₂ second positive band (C³IIu --> B³IIg) are measured, from which the molecule vibration temperatures of the light spot and the dim spot are calculated. Based on the relative intensity ratio of the line at 391.4 nm and the N₂ line at 394.1 nm, the average electron energies of the light spot and the dim spot are investigated. The broadening of spectral line 696.57 nm (2P₂-1S₅) is used to study the electron densities of the light spot and the dim spot. The experiment shows that the molecule vibration temperature, average electron energy and the electron density of the dim spot are higher than those of the light spot in the same argon content. The molecule vibration temperature and electron density of the light spot and dim spot increase with the argon content increasing from 70% to 95%, while average electron energies of the light spot and dim spot decrease gradually. The short-exposure image recorded by a high speed video camera shows that the dim spot results from the surface discharges (SDs). The surface discharge induced by the volume discharge (VD) has the decisive effect on the formation of the dim spot. The experiment above plays an important role in studying the formation mechanism of the hexagonal super-lattice pattern with light spot and

  3. The inheritance of the leopard complex of spotting patterns in horses.

    Science.gov (United States)

    Sponenberg, D P; Carr, G; Simak, E; Schwink, K

    1990-01-01

    The leopard complex of white spotting patterns in horses consists of the leopard, few-spot leopard, blanket, blanket with spots, varnish roan (or marble), snowflake, frosted, speckled, and mottled patterns. Horses with any of these patterns can produce the other patterns when mated to nonpatterned horses. Twenty-two horses of the Welsh Pony, Noriker, Appaloosa, and Pony of the Americas breeds produced 270 foals in a distribution consistent with a single dominant allele being responsible for the patterns. The symbol for this dominant allele, Lp, is retained from previous work on the leopard pattern. Heterozygotes are less extensively marked than are homozygotes, but the two classes overlap. The differences in the patterns are related to varying degrees of expression of this allele.

  4. Dynamic encryption method

    DEFF Research Database (Denmark)

    2013-01-01

    Disclosed is a method of transmitting a data set using encryption, wherein the method comprises the steps of: selecting a first encryption technique, wherein said first encryption technique comprises a first encryption algorithm for encrypting plain data into cipher data, and a first decryption...

  5. Method of rotation angle measurement in machine vision based on calibration pattern with spot array

    International Nuclear Information System (INIS)

    Li Weimin; Jin Jing; Li Xiaofeng; Li Bin

    2010-01-01

    We propose a method of rotation angle measurement with high precision in machine vision. An area scan CCD camera, imaging lens, and calibration pattern with a spot array make up the measurement device for measuring the rotation angle. The calibration pattern with a spot array is installed at the rotation part, and the CCD camera is set at a certain distance from the rotation components. The coordinates of the spots on the calibration pattern is acquired through the vision image of the calibration pattern captured by the CCD camera. At the initial position of the calibration pattern, the camera is calibrated with the spot array; the mathematical model of distortion error of the CCD camera is built. With the equation of coordinate rotation measurement, the rotation angle of the spot array is detected. In the theoretic simulation, noise of different levels is added to the coordinates of the spot array. The experiment results show that the measurement device can measure the rotation angle precisely with a noncontact method. The standard deviation of rotation angle measurement is smaller than 3 arc sec. The measurement device can measure both microangles and large angles.

  6. Image encryption a communication perspective

    CERN Document Server

    Abd El-Samie, Fathi E; Elashry, Ibrahim F; Shahieen, Mai H; Faragallah, Osama S; El-Rabaie, El-Sayed M; Alshebeili, Saleh A

    2013-01-01

    Presenting encryption algorithms with diverse characteristics, Image Encryption: A Communication Perspective examines image encryption algorithms for the purpose of secure wireless communication. It considers two directions for image encryption: permutation-based approaches encryption and substitution-based approaches.Covering the spectrum of image encryption principles and techniques, the book compares image encryption with permutation- and diffusion-based approaches. It explores number theory-based encryption algorithms such as the Data Encryption Standard, the Advanced Encryption Standard,

  7. Modeling Hot Spot Motor Vehicle Theft Crime in Relation to Landuse and Settlement Patterns

    Directory of Open Access Journals (Sweden)

    Djaka Marwasta

    2004-01-01

    Full Text Available The crowd of Yogyakarta urban has impacted its surrounding area, including Depok sub district, which is indicated by the rising of physical development, for example education facilities and settlements. The progress does not only bring positive impact, but also negative impact for instance the rising of crime number i.e. motor vehicle robbery. The aims of this research are 1 mapping motor vehicle robbery data as the distribution map and identifying motor vehicle robbery hot spot base on distrbution map; and 2 studying the correlation of motor vehicle robbery hot spot with physical environment phenomena, i.e. land use type and settlement pattern. The research method consists of two parts; they are motor vehicle robbery cluster analysis and the relation of motor vehicle robbery and physical environment analysis. Motor vehicle robbery cluster analysis is using distribution data, which analyzes the distribution into motor vehicle robbery hot spot with nearest neighbor tehnique. Contingency coefficient and frequency distribution analysis is used to analyze the correlation of motor vehicle robbery hot spot and physical environment. Contingency coefficient is used to study the relation of motor vehicle robbery hot spot polygon with physical environment condition, whereas frequency distribution is used to study the distribution of motor vehicle robbery in the hot spot with physical environment condition. Physical environment which consists of land use type, housing density, house regularity pattern, and the average of building size, are obtained from interpretation of black and white panchromatic aerial photograph year 2000, in the scale 1 : 20.000. the most motor vehicle robbery hot spot is found on the settlement area, 68,3% from 378 motor vehicle robbery cases in the hot spot. The seond level is found on the education area (16.4%. The most motor vehicle hot spot in the settlement is found on the hight density and irregular settlement, which have big

  8. Optical image encryption topology.

    Science.gov (United States)

    Yong-Liang, Xiao; Xin, Zhou; Qiong-Hua, Wang; Sheng, Yuan; Yao-Yao, Chen

    2009-10-15

    Optical image encryption topology is proposed based on the principle of random-phase encoding. Various encryption topological units, involving peer-to-peer, ring, star, and tree topologies, can be realized by an optical 6f system. These topological units can be interconnected to constitute an optical image encryption network. The encryption and decryption can be performed in both digital and optical methods.

  9. Electricity deregulation, spot price patterns and demand-side management

    International Nuclear Information System (INIS)

    Li, Y.; Flynn, P.C.

    2006-01-01

    This paper examines extensive hourly or half-hourly power price data from 14 deregulated power markets. It analyzes average diurnal patterns, relationship to system load, volatility, and consistency over time. Diurnal patterns indicate the average price spread between off-peak and on-peak and weekend vs. weekday power consumption. Volatility is measured by price velocity: the average normalized hourly change in power price, calculated daily. The calculated price velocity is broken down into an expected component that arises from the diurnal pattern and an unexpected component that arises from unknown factors. The analysis reveals significant differences among markets, suggesting that demand-side management (DSM) of power consumption is far more difficult in some markets than in others. At one extreme, Spain, Britain and Scandinavia show consistent diurnal price patterns, a stable relationship between price and system load, and a low unexplained component of price volatility. A power consumer in these markets could form a reasonable expectation of a reward for DSM of elective power consumption. At the other extreme, two markets in Australia show erratic diurnal price patterns from year to year, low correlation between price and system load, and a high amount of unexpected price velocity. A power consumer in these markets would have far greater difficulty in realizing a benefit from DSM. Markets that experienced one period of very high prices without a clear external cause, such as California and Alberta, appear to have a significant longer-term erosion of public support for deregulation. (author)

  10. Laser reflection spot as a pattern in a diamond coating – a microscopic study

    Directory of Open Access Journals (Sweden)

    GORDANA S. RISTIĆ

    2009-07-01

    Full Text Available Diamond coatings were deposited by the synchronous and coupled action of a hot filament CVD method and a pulsed CO2 laser in spectro-absorbing and spectro-non-absorbing diamond precursor atmospheres. The obtained coatings were structured/patterned, i.e., they were comprised of uncovered, bare locations. An extra effect observed only in the spectro-active diamond precursor atmosphere was the creation of another laser spot in the coating – a reflection spot. In order to establish the practical usability of the latter one, extensive microscopic investigations were performed with consideration of the morphology changes in the spot of the direct laser beam. Normal incidence SEM images of this spot showed a smooth surface, without any pulse radiation damage. AFM imaging revealed the actual surface condition and gave precise data on the surface characteristics.

  11. Diversification in a biodiversity hot spot: landscape correlates of phylogeographic patterns in the African spotted reed frog.

    Science.gov (United States)

    Lawson, Lucinda P

    2013-04-01

    The Eastern Afromontane Biodiversity Hotspot is known for microendemism and exceptional population genetic structure. The region's landscape heterogeneity is thought to limit gene flow between fragmented populations and create opportunities for regional adaptation, but the processes involved are poorly understood. Using a combination of phylogeographic analyses and circuit theory, I investigate how characteristics of landscape heterogeneity including regional distributions of slope, rivers and streams, habitat and hydrological basins (drainages) impact genetic distance among populations of the endemic spotted reed frog (Hyperolius substriatus), identifying corridors of connectivity as well as barriers to dispersal. Results show that genetic distance among populations is most strongly correlated to regional and local hydrologic structure and the distribution of suitable habitat corridors, not isolation by distance. Contrary to expectations, phylogeographic structure is not coincident with the two montane systems, but instead corresponds to the split between the region's two major hydrological basins (Zambezi and East Central Coastal). This results in a paraphyletic relationship for the Malawian Highlands populations with respect to the Eastern Arc Mountains and implies that the northern Malawian Highlands are the diversity centre for H. substriatus. Although the Malawian Highlands collectively hold the greatest genetic diversity, individual populations have lower diversity than their Eastern Arc counterparts, with an overall pattern of decreasing population diversity from north to south. Through the study of intraspecific differentiation across a mosaic of ecosystem and geographic heterogeneity, we gain insight into the processes of diversification and a broader understanding of the role of landscape in evolution. © 2013 Blackwell Publishing Ltd.

  12. On the interpretation of the forbidden spots observed in the electron diffraction patterns of flat Au triangular nanoparticles

    International Nuclear Information System (INIS)

    Reyes-Gasga, J.; Gomez-Rodriguez, A.; Gao Xiaoxia; Jose-Yacaman, M.

    2008-01-01

    In many cases nanostructures present forbidden spots in their electron diffraction patterns when they are observed by transmission electron microscopy (TEM). To interpretate their TEM and high resolution transmission electron microscopy (HRTEM) images properly, an understanding of the origin of these spots is necessary. In this work we comment on the origin of the forbidden spots observed in the [1 1 1] and [1 1 2] electron diffraction patterns of flat gold triangular nanoparticles. The forbidden spots were successfully indexed as corresponding to the first laue Zone (FOLZ) and the HRTEM images presented a contrast produced by the interference of the zero-order Laue zone (ZOLZ) and FOLZ spots. We discuss the use of the forbidden spots in the study of the structure of nanoparticles and show that they are related to the shape and incompleteness of layers in the very thin particles

  13. Compressive sensing based ptychography image encryption

    Science.gov (United States)

    Rawat, Nitin

    2015-09-01

    A compressive sensing (CS) based ptychography combined with an optical image encryption is proposed. The diffraction pattern is recorded through ptychography technique further compressed by non-uniform sampling via CS framework. The system requires much less encrypted data and provides high security. The diffraction pattern as well as the lesser measurements of the encrypted samples serves as a secret key which make the intruder attacks more difficult. Furthermore, CS shows that the linearly projected few random samples have adequate information for decryption with a dramatic volume reduction. Experimental results validate the feasibility and effectiveness of our proposed technique compared with the existing techniques. The retrieved images do not reveal any information with the original information. In addition, the proposed system can be robust even with partial encryption and under brute-force attacks.

  14. Vehicle security encryption based on unlicensed encryption

    Science.gov (United States)

    Huang, Haomin; Song, Jing; Xu, Zhijia; Ding, Xiaoke; Deng, Wei

    2018-03-01

    The current vehicle key is easy to be destroyed and damage, proposing the use of elliptical encryption algorithm is improving the reliability of vehicle security system. Based on the encryption rules of elliptic curve, the chip's framework and hardware structure are designed, then the chip calculation process simulation has been analyzed by software. The simulation has been achieved the expected target. Finally, some issues pointed out in the data calculation about the chip's storage control and other modules.

  15. Encryption for digital content

    CERN Document Server

    Kiayias, Aggelos

    2010-01-01

    Encryption for Digital Content is an area in cryptography that is widely used in commercial productions (e.g., Blu-Ray and HD-DVDs). This book provides a comprehensive mathematical treatment of combinatorial encryption techniques used in digital content distribution systems and related attack models. A complete description of broadcast encryption with various revocation and tracing functionalities is included. ""Encryption for Digital Content"" introduces the subset cover framework (currently used in AACS, Blu-Ray and HD-DVDs,) and tracking/revocation mechanisms in various attack models. Pirat

  16. Whisker spot patterns: a noninvasive method of individual identification of Australian sea lions (Neophoca cinerea)

    Science.gov (United States)

    Osterrieder, Sylvia K.; Salgado Kent, Chandra; Anderson, Carlos J. R.; Parnum, Iain M.; Robinson, Randall W.

    2015-01-01

    Reliable methods for identification of individual animals are advantageous for ecological studies of population demographics and movement patterns. Photographic identification, based on distinguishable patterns, unique shapes, or scars, is an effective technique already used for many species. We tested whether photographs of whisker spot patterns could be used to discriminate among individual Australian sea lion (Neophoca cinerea). Based on images of 53 sea lions, we simulated 5,000 patterns before calculating the probability of duplication in a study population. A total of 99% (± 1.5 SD) of patterns were considered reliable for a population of 50, 98% (± 1.7 SD) for 100, 92% (± 4.7 SD) for 500, and 88% (± 5.7 SD) for 1,000. We tested a semiautomatic approach by matching 16 known individuals at 3 different angles (70°, 90°, and 110°), 2 distances (1 and 2 m), and 6 separate times over a 1-year period. A point-pattern matching algorithm for pairwise comparisons produced 90% correct matches of photographs taken on the same day at 90°. Images of individuals at 1 and 2 m resulted in 89% correct matches, those photographed at different angles and different times (at 90°) resulted in 48% and 73% correct matches, respectively. Our results show that the Chamfer distance transform can effectively be used for individual identification, but only if there is very little variation in photograph angle. This point-pattern recognition application may also work for other otariid species. PMID:26937048

  17. Thermal analysis of continuous and patterned multilayer films in the presence of a nanoscale hot spot

    Directory of Open Access Journals (Sweden)

    Jia-Yang Juang

    2016-10-01

    Full Text Available Thermal responses of multilayer films play essential roles in state-of-the-art electronic systems, such as photo/micro-electronic devices, data storage systems, and silicon-on-insulator transistors. In this paper, we focus on the thermal aspects of multilayer films in the presence of a nanoscale hot spot induced by near field laser heating. The problem is set up in the scenario of heat assisted magnetic recording (HAMR, the next-generation technology to overcome the data storage density limit imposed by superparamagnetism. We characterized thermal responses of both continuous and patterned multilayer media films using transient thermal modeling. We observed that material configurations, in particular, the thermal barriers at the material layer interfaces crucially impact the temperature field hence play a key role in determining the hot spot geometry, transient response and power consumption. With a representative generic media model, we further explored the possibility of optimizing thermal performances by designing layers of heat sink and thermal barrier. The modeling approach demonstrates an effective way to characterize thermal behaviors of micro and nano-scale electronic devices with multilayer thin film structures. The insights into the thermal transport scheme will be critical for design and operations of such electronic devices.

  18. Thermal analysis of continuous and patterned multilayer films in the presence of a nanoscale hot spot

    Science.gov (United States)

    Juang, Jia-Yang; Zheng, Jinglin

    2016-10-01

    Thermal responses of multilayer films play essential roles in state-of-the-art electronic systems, such as photo/micro-electronic devices, data storage systems, and silicon-on-insulator transistors. In this paper, we focus on the thermal aspects of multilayer films in the presence of a nanoscale hot spot induced by near field laser heating. The problem is set up in the scenario of heat assisted magnetic recording (HAMR), the next-generation technology to overcome the data storage density limit imposed by superparamagnetism. We characterized thermal responses of both continuous and patterned multilayer media films using transient thermal modeling. We observed that material configurations, in particular, the thermal barriers at the material layer interfaces crucially impact the temperature field hence play a key role in determining the hot spot geometry, transient response and power consumption. With a representative generic media model, we further explored the possibility of optimizing thermal performances by designing layers of heat sink and thermal barrier. The modeling approach demonstrates an effective way to characterize thermal behaviors of micro and nano-scale electronic devices with multilayer thin film structures. The insights into the thermal transport scheme will be critical for design and operations of such electronic devices.

  19. New Encrypted Steganography Approach

    Directory of Open Access Journals (Sweden)

    Saba Mohammed Husain‎

    2017-12-01

    Full Text Available The proposed research Provides an approach for hiding an encrypted text in side a digital image. Where the text is encrypted in a complex manner used method of PlayFair to encrypt clear text and to increase security put lettering ciphertext on the geometric shape clockwise and then we write the ciphertext output in the form of lines, taken new ciphertext and converted to Ascii code and then to binary and hidden text in bits least importance in the picture. The results were good by PNSR scale

  20. Identity-based encryption

    CERN Document Server

    Chatterjee, Sanjit

    2011-01-01

    Identity Based Encryption (IBE) is a type of public key encryption and has been intensely researched in the past decade. Identity-Based Encryption summarizes the available research for IBE and the main ideas that would enable users to pursue further work in this area. This book will also cover a brief background on Elliptic Curves and Pairings, security against chosen Cipher text Attacks, standards and more. Advanced-level students in computer science and mathematics who specialize in cryptology, and the general community of researchers in the area of cryptology and data security will find Ide

  1. Investigating Encrypted Material

    Science.gov (United States)

    McGrath, Niall; Gladyshev, Pavel; Kechadi, Tahar; Carthy, Joe

    When encrypted material is discovered during a digital investigation and the investigator cannot decrypt the material then s/he is faced with the problem of how to determine the evidential value of the material. This research is proposing a methodology of extracting probative value from the encrypted file of a hybrid cryptosystem. The methodology also incorporates a technique for locating the original plaintext file. Since child pornography (KP) images and terrorist related information (TI) are transmitted in encrypted format the digital investigator must ask the question Cui Bono? - who benefits or who is the recipient? By doing this the scope of the digital investigation can be extended to reveal the intended recipient.

  2. Homomorphic encryption and applications

    CERN Document Server

    Yi, Xun; Bertino, Elisa

    2014-01-01

    This book introduces the fundamental concepts of homomorphic encryption. From these foundations, applications are developed in the fields of private information retrieval, private searching on streaming data, privacy-preserving data mining, electronic voting and cloud computing. The content is presented in an instructional and practical style, with concrete examples to enhance the reader's understanding. This volume achieves a balance between the theoretical and the practical components of modern information security. Readers will learn key principles of homomorphic encryption as well as their

  3. Encrypting personal identifiers.

    OpenAIRE

    Meux, E

    1994-01-01

    STUDY SETTING. A statewide patient discharge database contained only one unique identifier: the social security number (SSN). A method was developed to transform (encrypt) the SSN so that it could be made publicly available, for purposes of linking discharge records, without revealing the SSN itself. The method of encrypting the SSN into a Record Linkage Number (RLN) is described. PRINCIPAL FINDINGS. The same RLN will always result from the same SSN; it is highly improbable that the same RLN ...

  4. Genetic Basis of Body Color and Spotting Pattern in Redheaded Pine Sawfly Larvae (Neodiprion lecontei).

    Science.gov (United States)

    Linnen, Catherine R; O'Quin, Claire T; Shackleford, Taylor; Sears, Connor R; Lindstedt, Carita

    2018-03-01

    Pigmentation has emerged as a premier model for understanding the genetic basis of phenotypic evolution, and a growing catalog of color loci is starting to reveal biases in the mutations, genes, and genetic architectures underlying color variation in the wild. However, existing studies have sampled a limited subset of taxa, color traits, and developmental stages. To expand the existing sample of color loci, we performed quantitative trait locus (QTL) mapping analyses on two types of larval pigmentation traits that vary among populations of the redheaded pine sawfly ( Neodiprion lecontei ): carotenoid-based yellow body color and melanin-based spotting pattern. For both traits, our QTL models explained a substantial proportion of phenotypic variation and suggested a genetic architecture that is neither monogenic nor highly polygenic. Additionally, we used our linkage map to anchor the current N. lecontei genome assembly . With these data, we identified promising candidate genes underlying: (1) a loss of yellow pigmentation in populations in the Mid-Atlantic/northeastern USA [C locus-associated membrane protein homologous to a mammalian HDL receptor-2 gene ( Cameo2 ) and lipid transfer particle apolipoproteins II and I gene ( apoLTP-II/I )], and (2) a pronounced reduction in black spotting in Great-Lakes populations [members of the yellow gene family , tyrosine hydroxylase gene ( pale ) , and dopamine N- acetyltransferase gene ( Dat )]. Several of these genes also contribute to color variation in other wild and domesticated taxa. Overall, our findings are consistent with the hypothesis that predictable genes of large-effect contribute to color evolution in nature. Copyright © 2018, Genetics.

  5. Steganography and encrypting based on immunochemical systems.

    Science.gov (United States)

    Kim, Kyung-Woo; Bocharova, Vera; Halámek, Jan; Oh, Min-Kyu; Katz, Evgeny

    2011-05-01

    Steganography and encrypting were demonstrated with immuno-specific systems. IgG-proteins were used as invisible ink developed with complementary antibodies labeled with enzymes producing color spots. The information security was achieved by mixing the target protein-antigens used for the text encoding with masking proteins of similar composition but having different bioaffinity. Two different texts were simultaneously encoded by using two different encoding proteins in a mixture. Various encrypting techniques were exemplified with the immuno-systems used for the steganography. Future use of the developed approach for information protection and watermark-technology was proposed. Scaling down the encoded text to a micro-size is feasible with the use of nanotechnology. Copyright © 2010 Wiley Periodicals, Inc.

  6. Mother-Offspring Signature Whistle Similarity and Patterns of Association in Atlantic Spotted Dolphins (Stenella frontalis

    Directory of Open Access Journals (Sweden)

    Sara E. Bebus

    2015-02-01

    Full Text Available We assessed the degree of similarity between signature whistles of mother and offspring pairs in free-living Atlantic spotted dolphins (Stenella frontalis. As a means of qualitative evaluation, judges compared the time-frequency contour patterns of signature whistle spectrograms. We also evaluated quantitative measurements of whistle frequency and duration. All five female offspring produced signature whistles that were similar to their mothers’ whistles by a least one means of comparison, whereas two of the four male offspring produced signature whistles that were dissimilar from their mothers’ by both methods of comparison. However, statistically, male offspring were just as likely to produce signature whistles like their mothers’ as female offspring (p = 0.167. We compared whistle similarity between mothers and offspring to the degree of association for each pair. Offspring that most often associated with their mothers when they were four years of age had whistles that were more similar to their mothers’ whistles both qualitatively (r(4 = 0.92, p = 0.009 and quantitatively (r(4 = 0.92, p = 0.004. Because signature whistles are developed within a dolphin’s first year, our finding likely reflects the level of bond between mother and calf.

  7. The fast encryption package

    Science.gov (United States)

    Bishop, Matt

    1988-01-01

    The organization of some tools to help improve passwork security at a UNIX-based site is described along with how to install and use them. These tools and their associated library enable a site to force users to pick reasonably safe passwords (safe being site configurable) and to enable site management to try to crack existing passworks. The library contains various versions of a very fast implementation of the Data Encryption Standard and of the one-way encryption functions used to encryp the password.

  8. Global Diffusion Pattern and Hot SPOT Analysis of Vaccine-Preventable Diseases

    Science.gov (United States)

    Jiang, Y.; Fan, F.; Zanoni, I. Holly; Li, Y.

    2017-10-01

    Spatial characteristics reveal the concentration of vaccine-preventable disease in Africa and the Near East and that disease dispersion is variable depending on disease. The exception is whooping cough, which has a highly variable center of concentration from year to year. Measles exhibited the only statistically significant spatial autocorrelation among all the diseases under investigation. Hottest spots of measles are in Africa and coldest spots are in United States, warm spots are in Near East and cool spots are in Western Europe. Finally, cases of measles could not be explained by the independent variables, including Gini index, health expenditure, or rate of immunization. Since the literature confirms that each of the selected variables is considered determinants of disease dissemination, it is anticipated that the global dataset of disease cases was influenced by reporting bias.

  9. Searching in Encrypted Data

    NARCIS (Netherlands)

    Doumen, J.M.; Brinkman, Richard; Jonker, Willem

    2004-01-01

    The amount of data an average person has, is becoming so huge that in the near future this cannot be stored locally anymore, and an external server will have to be used. When this server is not (entirely) trusted, the data should be encrypted. However, the data should still be accessible as a

  10. Technical Note: Validation of halo modeling for proton pencil beam spot scanning using a quality assurance test pattern

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Liyong, E-mail: linl@uphs.upenn.edu; Huang, Sheng; Kang, Minglei; Solberg, Timothy D.; McDonough, James E.; Ainsley, Christopher G. [Department of Radiation Oncology, University of Pennsylvania, 3400 Civic Center Boulevard, Philadelphia, Pennsylvania 19104 (United States)

    2015-09-15

    Purpose: The purpose of this paper is to demonstrate the utility of a comprehensive test pattern in validating calculation models that include the halo component (low-dose tails) of proton pencil beam scanning (PBS) spots. Such a pattern has been used previously for quality assurance purposes to assess spot shape, position, and dose. Methods: In this study, a scintillation detector was used to measure the test pattern in air at isocenter for two proton beam energies (115 and 225 MeV) of two IBA universal nozzles (UN #1 and UN #2). Planar measurements were compared with calculated dose distributions based on the weighted superposition of location-independent (UN #1) or location-dependent (UN #2) spot profiles, previously measured using a pair-magnification method and between two nozzles. Results: Including the halo component below 1% of the central dose is shown to improve the gamma-map comparison between calculation and measurement from 94.9% to 98.4% using 2 mm/2% criteria for the 115 MeV proton beam of UN #1. In contrast, including the halo component below 1% of the central dose does not improve the gamma agreement for the 115 MeV proton beam of UN #2, due to the cutoff of the halo component at off-axis locations. When location-dependent spot profiles are used for calculation instead of spot profiles at central axis, the gamma agreement is improved from 98.0% to 99.5% using 2 mm/2% criteria. The two nozzles clearly have different characteristics, as a direct comparison of measured data shows a passing rate of 89.7% for the 115 MeV proton beam. At 225 MeV, the corresponding gamma comparisons agree better between measurement and calculation, and between measurements in the two nozzles. Conclusions: In addition to confirming the primary component of individual PBS spot profiles, a comprehensive test pattern is useful for the validation of the halo component at off-axis locations, especially for low energy protons.

  11. Chaos based encryption system for encrypting electroencephalogram signals.

    Science.gov (United States)

    Lin, Chin-Feng; Shih, Shun-Han; Zhu, Jin-De

    2014-05-01

    In the paper, we use the Microsoft Visual Studio Development Kit and C# programming language to implement a chaos-based electroencephalogram (EEG) encryption system involving three encryption levels. A chaos logic map, initial value, and bifurcation parameter for the map were used to generate Level I chaos-based EEG encryption bit streams. Two encryption-level parameters were added to these elements to generate Level II chaos-based EEG encryption bit streams. An additional chaotic map and chaotic address index assignment process was used to implement the Level III chaos-based EEG encryption system. Eight 16-channel EEG Vue signals were tested using the encryption system. The encryption was the most rapid and robust in the Level III system. The test yielded superior encryption results, and when the correct deciphering parameter was applied, the EEG signals were completely recovered. However, an input parameter error (e.g., a 0.00001 % initial point error) causes chaotic encryption bit streams, preventing the recovery of 16-channel EEG Vue signals.

  12. Encryption is Useless!?

    CERN Multimedia

    IT Department

    2011-01-01

    This week FTP (the file transfer protocol) celebrated its 40th birthday - and will hopefully retire soon! While a nice and simple means of transferring files, it is totally insecure: both the transferred contents and the authentication password are transfered unencrypted. FTP is not the only protocol that transfers data unencrypted: standard web traffic (“HTTP”) and e-mail (“SMTP”) are not encrypted either. Not an issue? Think again! Nowadays, we all use wireless Ethernet from our laptops and mobile phones. This means that your traffic can be intercepted by anyone*… What if I could your web browsing history, read your last e-mail to your boyfriend/girlfriend, or see which commands you’ve just executed? I could easily intercept your Facebook session… If this worries you, check for secrecy and encryption. Usually this is shown by an “S” in your communication protocol:   · “HTTPS&...

  13. The end of encryption

    CERN Multimedia

    Computer Security Team

    2013-01-01

    Sigh! Pandora’s box has been opened (once again). Recent documents leaked by whistle-blower Edward Snowden have revealed that the NSA project “Bullrun” is intruding deeply into the confidentiality of our documents and the privacy of our lives.   In their continuous effort to kill privacy on the Internet, the US National Security Agency (NSA) and the British Government Communications Headquarters (GCHQ) have made significant progress in breaking almost every basic encryption protocol or have developed the means to bypass them. “US and British intelligence agencies have successfully cracked much of the online encryption relied upon by hundreds of millions of people to protect the privacy of their personal data, online transactions and e-mails.” - The Guardian So what’s left? With “Prism” and “Tempora”, our public communication on the Internet was already filtered and analysed (see our Bulletin ar...

  14. Matched filtering Generalized Phase Contrast using binary phase for dynamic spot- and line patterns in biophotonics and structured lighting.

    Science.gov (United States)

    Bañas, Andrew; Aabo, Thomas; Palima, Darwin; Glückstad, Jesper

    2013-01-28

    This work discusses the use of matched filtering Generalized Phase Contrast (mGPC) as an efficient and cost-effective beam shaper for applications such as in biophotonics, optical micromanipulation, microscopy and two-photon polymerization. The theoretical foundation of mGPC is described as a combination of Generalized Phase Contrast and phase-only correlation. Such an analysis makes it convenient to optimize an mGPC system for different setup conditions. Results showing binary-only phase generation of dynamic spot arrays and line patterns are presented.

  15. Matched filtering Generalized Phase Contrast using binary phase for dynamic spot- and line patterns in biophotonics and structured lighting

    DEFF Research Database (Denmark)

    Bañas, Andrew Rafael; Aabo, Thomas; Palima, Darwin

    2013-01-01

    as a combination of Generalized Phase Contrast and phase-only correlation. Such an analysis makes it convenient to optimize an mGPC system for different setup conditions. Results showing binary-only phase generation of dynamic spot arrays and line patterns are presented. © 201 Optical Society of America......This work discusses the use of matched filtering Generalized Phase Contrast (mGPC) as an efficient and cost-effective beam shaper for applications such as in biophotonics, optical micromanipulation, microscopy and two-photon polymerization. The theoretical foundation of mGPC is described...

  16. Early stage hot spot analysis through standard cell base random pattern generation

    Science.gov (United States)

    Jeon, Joong-Won; Song, Jaewan; Kim, Jeong-Lim; Park, Seongyul; Yang, Seung-Hune; Lee, Sooryong; Kang, Hokyu; Madkour, Kareem; ElManhawy, Wael; Lee, SeungJo; Kwan, Joe

    2017-04-01

    Due to limited availability of DRC clean patterns during the process and RET recipe development, OPC recipes are not tested with high pattern coverage. Various kinds of pattern can help OPC engineer to detect sensitive patterns to lithographic effects. Random pattern generation is needed to secure robust OPC recipe. However, simple random patterns without considering real product layout style can't cover patterning hotspot in production levels. It is not effective to use them for OPC optimization thus it is important to generate random patterns similar to real product patterns. This paper presents a strategy for generating random patterns based on design architecture information and preventing hotspot in early process development stage through a tool called Layout Schema Generator (LSG). Using LSG, we generate standard cell based on random patterns reflecting real design cell structure - fin pitch, gate pitch and cell height. The output standard cells from LSG are applied to an analysis methodology to assess their hotspot severity by assigning a score according to their optical image parameters - NILS, MEEF, %PV band and thus potential hotspots can be defined by determining their ranking. This flow is demonstrated on Samsung 7nm technology optimizing OPC recipe and early enough in the process avoiding using problematic patterns.

  17. Matrix Encryption Scheme

    Directory of Open Access Journals (Sweden)

    Abdelhakim Chillali

    2017-05-01

    Full Text Available In classical cryptography, the Hill cipher is a polygraphic substitution cipher based on linear algebra. In this work, we proposed a new problem applicable to the public key cryptography, based on the Matrices, called “Matrix discrete logarithm problem”, it uses certain elements formed by matrices whose coefficients are elements in a finite field. We have constructed an abelian group and, for the cryptographic part in this unreliable group, we then perform the computation corresponding to the algebraic equations, Returning the encrypted result to a receiver. Upon receipt of the result, the receiver can retrieve the sender’s clear message by performing the inverse calculation.

  18. Private genome analysis through homomorphic encryption.

    Science.gov (United States)

    Kim, Miran; Lauter, Kristin

    2015-01-01

    The rapid development of genome sequencing technology allows researchers to access large genome datasets. However, outsourcing the data processing o the cloud poses high risks for personal privacy. The aim of this paper is to give a practical solution for this problem using homomorphic encryption. In our approach, all the computations can be performed in an untrusted cloud without requiring the decryption key or any interaction with the data owner, which preserves the privacy of genome data. We present evaluation algorithms for secure computation of the minor allele frequencies and χ2 statistic in a genome-wide association studies setting. We also describe how to privately compute the Hamming distance and approximate Edit distance between encrypted DNA sequences. Finally, we compare performance details of using two practical homomorphic encryption schemes--the BGV scheme by Gentry, Halevi and Smart and the YASHE scheme by Bos, Lauter, Loftus and Naehrig. The approach with the YASHE scheme analyzes data from 400 people within about 2 seconds and picks a variant associated with disease from 311 spots. For another task, using the BGV scheme, it took about 65 seconds to securely compute the approximate Edit distance for DNA sequences of size 5K and figure out the differences between them. The performance numbers for BGV are better than YASHE when homomorphically evaluating deep circuits (like the Hamming distance algorithm or approximate Edit distance algorithm). On the other hand, it is more efficient to use the YASHE scheme for a low-degree computation, such as minor allele frequencies or χ2 test statistic in a case-control study.

  19. SDMS-based Disk Encryption Method

    OpenAIRE

    An, Dokjun; Ri, Myongchol; Choe, Changil; Han, Sunam; Kim, Yongmin

    2012-01-01

    We propose a disk encryption method, called secure disk mixed system (SDMS) in this paper, for data protection of disk storages such as USB flash memory, USB hard disk and CD/DVD. It is aimed to solve temporal and spatial limitation problems of existing disk encryption methods and to control security performance flexibly according to the security requirement of system. SDMS stores data by encrypting with different encryption key per sector and updates sector encryption keys each time data is ...

  20. Image Encryption Using a Lightweight Stream Encryption Algorithm

    Directory of Open Access Journals (Sweden)

    Saeed Bahrami

    2012-01-01

    Full Text Available Security of the multimedia data including image and video is one of the basic requirements for the telecommunications and computer networks. In this paper, we consider a simple and lightweight stream encryption algorithm for image encryption, and a series of tests are performed to confirm suitability of the described encryption algorithm. These tests include visual test, histogram analysis, information entropy, encryption quality, correlation analysis, differential analysis, and performance analysis. Based on this analysis, it can be concluded that the present algorithm in comparison to A5/1 and W7 stream ciphers has the same security level, is better in terms of the speed of performance, and is used for real-time applications.

  1. Pattern of the Occurrence of Tomato spotted wilt virus in Jeonnam Province

    Directory of Open Access Journals (Sweden)

    Sug-Ju Ko

    2013-12-01

    Full Text Available Tomato spotted wilt virus (TSWV was occurred at 8 areas including Naju, Suncheon, Younggwang, Youngam, and Shinan in Jeonnam province and the crops of Younggwang were severely damaged by TSWV. The hot pepper (Capsicum annuum, bell pepper (Capsicum annuum v ar. angulosum and tomato (Solanum lycopersicon in greenhouse and hot pepper in open field were infected by TSWV. Especially, hot pepper was severely damaged by TSWV infection. The survey data indicated that 1.1−30% in the nursery field at Naju, Suncheon, and Jangheung were infected by TSWV. Plants were infected by TSWV from early June to August. However, TSWV-infected seedlings from nursery fields showed the disease symptoms from May after transplanting. In pepper greenhouses, Frankliniella occidentalis was more dominant insect vector than Frankliniella intonsa. But in open field, the population of insect vector was opposed to greenhouse. In addition, the removal of weeds was able to delay the incidence of TSWV via side-window of greenhouse in Winter. Taken together, the control of weed and insect vector nearby side-window of greenhouse is important to prevent TSWV infection of plants.

  2. Quantum computing on encrypted data.

    Science.gov (United States)

    Fisher, K A G; Broadbent, A; Shalm, L K; Yan, Z; Lavoie, J; Prevedel, R; Jennewein, T; Resch, K J

    2014-01-01

    The ability to perform computations on encrypted data is a powerful tool for protecting privacy. Recently, protocols to achieve this on classical computing systems have been found. Here, we present an efficient solution to the quantum analogue of this problem that enables arbitrary quantum computations to be carried out on encrypted quantum data. We prove that an untrusted server can implement a universal set of quantum gates on encrypted quantum bits (qubits) without learning any information about the inputs, while the client, knowing the decryption key, can easily decrypt the results of the computation. We experimentally demonstrate, using single photons and linear optics, the encryption and decryption scheme on a set of gates sufficient for arbitrary quantum computations. As our protocol requires few extra resources compared with other schemes it can be easily incorporated into the design of future quantum servers. These results will play a key role in enabling the development of secure distributed quantum systems.

  3. Security analysis of optical encryption

    OpenAIRE

    Frauel, Yann; Castro, Albertina; Naughton, Thomas J.; Javidi, Bahram

    2005-01-01

    This paper analyzes the security of amplitude encoding for double random phase encryption. We describe several types of attack. The system is found to be resistant to brute-force attacks but vulnerable to chosen and known plaintext attacks.

  4. Security analysis of optical encryption

    Science.gov (United States)

    Frauel, Yann; Castro, Albertina; Naughton, Thomas J.; Javidi, Bahram

    2005-10-01

    This paper analyzes the security of amplitude encoding for double random phase encryption. We describe several types of attack. The system is found to be resistant to brute-force attacks but vulnerable to chosen and known plaintext attacks.

  5. The Lure of Wireless Encryption

    CERN Multimedia

    Computer Security Team

    2013-01-01

    Following our article entitled “Jekyll or Hyde? Better browse securely” in the last issue of the Bulletin, some people wondered why the CERN wireless network is not encrypted…   There are many arguments why it is not. The simplest is usability: the communication and management of the corresponding access keys would be challenging given the sheer number of wireless devices the CERN network hosts. Keys would quickly become public, e.g. at conferences, and might be shared, written on whiteboards, etc. Then there are all the devices which cannot be easily configured to use encryption protocols - a fact which would create plenty of calls to the CERN Service Desk… But our main argument is that wireless encryption is DECEPTIVE. Wireless encryption is deceptive as it only protects the wireless network against unauthorised access (and the CERN network already has other means to protect against that). Wireless encryption however, does not really help you. You ...

  6. Cranial arterial pattern of the Sri Lankan spotted chevrotain, Moschiola memmina, and comparative basicranial osteology of the Tragulidae

    Science.gov (United States)

    2015-01-01

    The cranial arterial pattern of artiodactyls deviates significantly from the typical mammalian pattern. One of the most striking atypical features is the rete mirabile epidurale: a subdural arterial meshwork that functionally and anatomically replaces the arteria carotis interna. This meshwork facilitates an exceptional ability to cool the brain, and was thought to be present in all artiodactyls. Recent research, however, has found that species of mouse deer (Artiodactyla: Tragulidae) endemic to the Malay Archipelago possess a complete a. carotis interna instead of a rete mirabile epidurale. As tragulids are the sister group to pecoran ruminants, the lack of a rete mirabile epidurale in these species raises intriguing evolutionary questions about the origin and nature of artiodactyl thermoregulatory cranial vasculature. In this study, cranial arterial patterns are documented for the remaining species within the Tragulidae. Radiopaque latex vascular injection, computed tomography (CT-scanning), and digital 3-dimensional anatomical reconstruction are used to image the cranial arteries of a Sri Lankan spotted chevrotain, Moschiola meminna. Sites of hard and soft tissue interaction were identified, and these osteological correlates were then sought in nine skulls representative of the remaining tragulid species. Both hard and soft tissue surveys confirm that the presence of an a. carotis interna is the common condition for tragulids. Moreover, the use of a 3-D, radiographic anatomical imaging technique enabled identification of a carotico-maxillary anastomosis that may have implications for the evolution of the artiodactyl rete mirabile epidurale. PMID:26644983

  7. Cranial arterial pattern of the Sri Lankan spotted chevrotain, Moschiola memmina, and comparative basicranial osteology of the Tragulidae.

    Science.gov (United States)

    O'Brien, Haley D

    2015-01-01

    The cranial arterial pattern of artiodactyls deviates significantly from the typical mammalian pattern. One of the most striking atypical features is the rete mirabile epidurale: a subdural arterial meshwork that functionally and anatomically replaces the arteria carotis interna. This meshwork facilitates an exceptional ability to cool the brain, and was thought to be present in all artiodactyls. Recent research, however, has found that species of mouse deer (Artiodactyla: Tragulidae) endemic to the Malay Archipelago possess a complete a. carotis interna instead of a rete mirabile epidurale. As tragulids are the sister group to pecoran ruminants, the lack of a rete mirabile epidurale in these species raises intriguing evolutionary questions about the origin and nature of artiodactyl thermoregulatory cranial vasculature. In this study, cranial arterial patterns are documented for the remaining species within the Tragulidae. Radiopaque latex vascular injection, computed tomography (CT-scanning), and digital 3-dimensional anatomical reconstruction are used to image the cranial arteries of a Sri Lankan spotted chevrotain, Moschiola meminna. Sites of hard and soft tissue interaction were identified, and these osteological correlates were then sought in nine skulls representative of the remaining tragulid species. Both hard and soft tissue surveys confirm that the presence of an a. carotis interna is the common condition for tragulids. Moreover, the use of a 3-D, radiographic anatomical imaging technique enabled identification of a carotico-maxillary anastomosis that may have implications for the evolution of the artiodactyl rete mirabile epidurale.

  8. Landscape Use and Co-Occurrence Patterns of Neotropical Spotted Cats

    Science.gov (United States)

    Nagy-Reis, Mariana B.; Nichols, James D.; Chiarello, Adriano G.; Ribeiro, Milton Cezar; Setz, Eleonore Z. F.

    2017-01-01

    Small felids influence ecosystem dynamics through prey and plant population changes. Although most of these species are threatened, they are accorded one of the lowest research efforts of all felids, and we lack basic information about them. Many felids occur in sympatry, where intraguild competition is frequent. Therefore, assessing the role of interspecific interactions along with the relative importance of landscape characteristics is necessary to understand how these species co-occur in space. Here, we selected three morphologically similar and closely related species of small Neotropical cats to evaluate the roles of interspecific interactions, geomorphometry, environmental, and anthropogenic landscape characteristics on their habitat use. We collected data with camera trapping and scat sampling in a large protected Atlantic forest remnant (35,000 ha). Throughout occupancy modeling we investigated whether these species occur together more or less frequently than would be expected by chance, while dealing with imperfect detection and incorporating possible habitat preferences into the models. We used occupancy as a measure of their habitat use. Although intraguild competition can be an important determinant of carnivore assemblages, in our system, we did not find evidence that one species affects the habitat use of the other. Evidence suggested that proximity to the nature reserve (a more protected area) was a more important driver of Neotropical spotted cats’ occurrence than interspecific interactions or geomorphometry and environmental landscape characteristics—even though our entire study area is under some type of protection. This suggests that small felids can be sensitive to the area protection status, emphasizing the importance of maintaining and creating reserves and other areas with elevated protection for the proper management and conservation of the group. PMID:28052073

  9. Landscape Use and Co-Occurrence Patterns of Neotropical Spotted Cats.

    Directory of Open Access Journals (Sweden)

    Mariana B Nagy-Reis

    Full Text Available Small felids influence ecosystem dynamics through prey and plant population changes. Although most of these species are threatened, they are accorded one of the lowest research efforts of all felids, and we lack basic information about them. Many felids occur in sympatry, where intraguild competition is frequent. Therefore, assessing the role of interspecific interactions along with the relative importance of landscape characteristics is necessary to understand how these species co-occur in space. Here, we selected three morphologically similar and closely related species of small Neotropical cats to evaluate the roles of interspecific interactions, geomorphometry, environmental, and anthropogenic landscape characteristics on their habitat use. We collected data with camera trapping and scat sampling in a large protected Atlantic forest remnant (35,000 ha. Throughout occupancy modeling we investigated whether these species occur together more or less frequently than would be expected by chance, while dealing with imperfect detection and incorporating possible habitat preferences into the models. We used occupancy as a measure of their habitat use. Although intraguild competition can be an important determinant of carnivore assemblages, in our system, we did not find evidence that one species affects the habitat use of the other. Evidence suggested that proximity to the nature reserve (a more protected area was a more important driver of Neotropical spotted cats' occurrence than interspecific interactions or geomorphometry and environmental landscape characteristics-even though our entire study area is under some type of protection. This suggests that small felids can be sensitive to the area protection status, emphasizing the importance of maintaining and creating reserves and other areas with elevated protection for the proper management and conservation of the group.

  10. Stegano-Crypto Hiding Encrypted Data in Encrypted Image Using Advanced Encryption Standard and Lossy Algorithm

    Directory of Open Access Journals (Sweden)

    Ari Shawakat Tahir

    2015-12-01

    Full Text Available The Steganography is an art and science of hiding information by embedding messages within other, seemingly harmless messages and lots of researches are working in it. Proposed system is using AES Algorithm and Lossy technique to overcome the limitation of previous work and increasing the process’s speed. The sender uses AES Algorithm to encrypt message and image, then using LSB technique to hide encrypted data in encrypted message. The receive get the original data using the keys that had been used in encryption process. The proposed system has been implemented in NetBeans 7.3 software uses image and data in different size to find the system’s speed.

  11. Encryption Technology based on Human Biometrics

    Directory of Open Access Journals (Sweden)

    Wei Yang

    2017-08-01

    Full Text Available The research progress of encryption technologies based on human biometrics is reviewed in this paper.The technologies that utilize human biometrics to make information encryption and identity authentication,and the technologies which combine biometrics encryption with optical encryption methods are introduced in detail.The advantages and disadvantages of these encryption systems are discussed,and the obstacles in practical applications are pointed out.Finally,the prospect of the new encryption technologies that are based on human biometrics are predicted.

  12. Image Encryption on Mobile Phone Using Super Encryption Algorithm

    Directory of Open Access Journals (Sweden)

    Catur Iswahyudi

    2012-12-01

    Full Text Available This study aims to obtain the digital image encryption algorithm with a simple but secure process, fast and efficient computing resources. The algorithms developed in this study were super-encryption algorithm that combines two of cipher called Playfair cipher and the Vigenere cipher. To improve security, a keystream generator was used to randomize the order of the next key in Vigenere cipher. In order to evaluate performance, the proposed algorithm was measured through a series of tests. These tests were implemented with Matlab included visual test and histogram analysis, information entropy, encryption quality, correlation analysis, and also time analysis. The test results show that cipher  image looks visually random.The image histogram of the plain image and cipher image also seen a significant difference between the two of them. Testing was also performed on mobile phones with Symbian and BADA operating system based on Java Micro Edition Programming. Trial results show that the algorithm was require less computational resources; with average time for image encryption is 3.76 seconds, and the average time  for image decryption is 0.97 seconds. The new proposed image encryption scheme has satisfactory security which makes it a potential candidate for encryption of image data.   Keywords:  Image encryption, Vigenere cipher, Playfair cipher, Security test

  13. A tale of two seas: contrasting patterns of population structure in the small-spotted catshark across Europe

    Science.gov (United States)

    Gubili, Chrysoula; Sims, David W.; Veríssimo, Ana; Domenici, Paolo; Ellis, Jim; Grigoriou, Panagiotis; Johnson, Andrew F.; McHugh, Matthew; Neat, Francis; Satta, Andrea; Scarcella, Giuseppe; Serra-Pereira, Bárbara; Soldo, Alen; Genner, Martin J.; Griffiths, Andrew M.

    2014-01-01

    Elasmobranchs represent important components of marine ecosystems, but they can be vulnerable to overexploitation. This has driven investigations into the population genetic structure of large-bodied pelagic sharks, but relatively little is known of population structure in smaller demersal taxa, which are perhaps more representative of the biodiversity of the group. This study explores spatial population genetic structure of the small-spotted catshark (Scyliorhinus canicula), across European seas. The results show significant genetic differences among most of the Mediterranean sample collections, but no significant structure among Atlantic shelf areas. The data suggest the Mediterranean populations are likely to have persisted in a stable and structured environment during Pleistocene sea-level changes. Conversely, the Northeast Atlantic populations would have experienced major changes in habitat availability during glacial cycles, driving patterns of population reduction and expansion. The data also provide evidence of male-biased dispersal and female philopatry over large spatial scales, implying complex sex-determined differences in the behaviour of elasmobranchs. On the basis of this evidence, we suggest that patterns of connectivity are determined by trends of past habitat stability that provides opportunity for local adaptation in species exhibiting philopatric behaviour, implying that resilience of populations to fisheries and other stressors may differ across the range of species. PMID:26064555

  14. Ancient DNA analyses reveal contrasting phylogeographic patterns amongst kiwi (Apteryx spp. and a recently extinct lineage of spotted kiwi.

    Directory of Open Access Journals (Sweden)

    Lara D Shepherd

    Full Text Available The little spotted kiwi (Apteryx owenii is a flightless ratite formerly found throughout New Zealand but now greatly reduced in distribution. Previous phylogeographic studies of the related brown kiwi (A. mantelli, A. rowi and A. australis, with which little spotted kiwi was once sympatric, revealed extremely high levels of genetic structuring, with mitochondrial DNA haplotypes often restricted to populations. We surveyed genetic variation throughout the present and pre-human range of little spotted kiwi by obtaining mitochondrial DNA sequences from contemporary and ancient samples. Little spotted kiwi and great spotted kiwi (A. haastii formed a monophyletic clade sister to brown kiwi. Ancient samples of little spotted kiwi from the northern North Island, where it is now extinct, formed a lineage that was distinct from remaining little spotted kiwi and great spotted kiwi lineages, potentially indicating unrecognized taxonomic diversity. Overall, little spotted kiwi exhibited much lower levels of genetic diversity and structuring than brown kiwi, particularly through the South Island. Our results also indicate that little spotted kiwi (or at least hybrids involving this species survived on the South Island mainland until more recently than previously thought.

  15. Semi-Homomorphic Encryption and Multiparty Computation

    DEFF Research Database (Denmark)

    Bendlin, Rikke; Damgård, Ivan Bjerre; Orlandi, Claudio

    2011-01-01

    An additively-homomorphic encryption scheme enables us to compute linear functions of an encrypted input by manipulating only the ciphertexts. We define the relaxed notion of a semi-homomorphic encryption scheme, where the plaintext can be recovered as long as the computed function does not incre......An additively-homomorphic encryption scheme enables us to compute linear functions of an encrypted input by manipulating only the ciphertexts. We define the relaxed notion of a semi-homomorphic encryption scheme, where the plaintext can be recovered as long as the computed function does...... not increase the size of the input “too much”. We show that a number of existing cryptosystems are captured by our relaxed notion. In particular, we give examples of semi-homomorphic encryption schemes based on lattices, subset sum and factoring. We then demonstrate how semi-homomorphic encryption schemes...

  16. Selective Document Retrieval from Encrypted Database

    NARCIS (Netherlands)

    Bösch, C.T.; Tang, Qiang; Hartel, Pieter H.; Jonker, Willem

    We propose the concept of selective document retrieval (SDR) from an encrypted database which allows a client to store encrypted data on a third-party server and perform efficient search remotely. We propose a new SDR scheme based on the recent advances in fully homomorphic encryption schemes. The

  17. Homomorphic encryption and secure comparison

    DEFF Research Database (Denmark)

    Damgård, Ivan Bjerre; Geisler, Martin; Krøigaard, Mikkel

    2008-01-01

    We propose a protocol for secure comparison of integers based on homomorphic encryption.We also propose a homomorphic encryption scheme that can be used in our protocol, makes it more efficient than previous solutions, and can also be used as the basis of efficient and general secure Multiparty...... Computation (MPC). We show how our comparison protocol can be used to improve security of online auctions, and demonstrate that it is efficient enough to be used in practice. For comparison of 16 bits numbers with security based on 1024 bits RSA (executed by two parties), our implementation takes 0.28 sec...

  18. Mediated Encryption: Analysis and Design

    Directory of Open Access Journals (Sweden)

    I. Elashry1

    2015-01-01

    Full Text Available Boneh, Ding and Tsudik presented identity-based mediated RSA encryption and signature systems in which the users are not allowed to decrypt/sign messages without the authorisation of a security mediator.We show that ID-MRSA is not secure and we present a secure modified version of it which is as efficient as the original system. We also propose a generic mediated encryption that translates any identity based encryption to a mediated version of this IBE. It envelops an IBE encrypted message using a user’s identity into an IBE envelope using the identity of the SEM. We present two security models based on the role of the adversary whether it is a revoked user or a hacked SEM. We prove that GME is as secure as the SEM’s IBE against a revoked user and as secure as the user’s IBE against a hacked SEM. We also present two implementations of GME based on Boneh-Franklin FullIBE system which is a pairing-based system and Boneh, Gentry and Hamburg (BGH system which is pairing-free system.

  19. Polarisation Encryption/Decryption Module

    DEFF Research Database (Denmark)

    2002-01-01

    A polarisation encryption/decryption module comprising at least two array based modulating devices, preferably spatial light modulators (SLMs), at least one array based intensity detector, and at least one source of electromagnetic radiation. A local region of information displayed on a first...

  20. Optical image encryption based on interference under convergent random illumination

    International Nuclear Information System (INIS)

    Kumar, Pramod; Joseph, Joby; Singh, Kehar

    2010-01-01

    In an optical image encryption system based on the interference principle, two pure phase masks are designed analytically to hide an image. These two masks are illuminated with a plane wavefront to retrieve the original image in the form of an interference pattern at the decryption plane. Replacement of the plane wavefront with convergent random illumination in the proposed scheme leads to an improvement in the security of interference based encryption. The proposed encryption scheme retains the simplicity of an interference based method, as the two pure masks are generated with an analytical method without any iterative algorithm. In addition to the free-space propagation distance and the two pure phase masks, the convergence distance and the randomized lens phase function are two new encryption parameters to enhance the system security. The robustness of this scheme against occlusion of the random phase mask of the randomized lens phase function is investigated. The feasibility of the proposed scheme is demonstrated with numerical simulation results

  1. Optical image encryption based on interference under convergent random illumination

    Science.gov (United States)

    Kumar, Pramod; Joseph, Joby; Singh, Kehar

    2010-09-01

    In an optical image encryption system based on the interference principle, two pure phase masks are designed analytically to hide an image. These two masks are illuminated with a plane wavefront to retrieve the original image in the form of an interference pattern at the decryption plane. Replacement of the plane wavefront with convergent random illumination in the proposed scheme leads to an improvement in the security of interference based encryption. The proposed encryption scheme retains the simplicity of an interference based method, as the two pure masks are generated with an analytical method without any iterative algorithm. In addition to the free-space propagation distance and the two pure phase masks, the convergence distance and the randomized lens phase function are two new encryption parameters to enhance the system security. The robustness of this scheme against occlusion of the random phase mask of the randomized lens phase function is investigated. The feasibility of the proposed scheme is demonstrated with numerical simulation results.

  2. The Techniques for Arbitrary Secure Quering to Encrypted Cloud Database Using Fully Homomorphic Encryption

    Directory of Open Access Journals (Sweden)

    Filipp B. Burtyka

    2017-06-01

    Full Text Available The processing of queries to an encrypted database without its decryption has been actively investigated recently by both cryptographers and database researchers. Such a work is allowed by various types of so-called Processable encryption (PE, as well as special architectures of database management systems (DBMS which use these types of encryption. The most known types of PEs are order-preserving encryption, homomorphic encryption, functional encryption, searchable encryption, and property-preserving encryption. Based on these types of encryption, various DBMSs are built, the most famous of which are CryptDB, Mo- nomi, Arx and DBMS by researchers from Novosibirsk. These DBMSs are built on the basis of various types of PEs, for example order-preserving encryption, homomorphic encryption and traditional block encryption. However, this approach can cause privacy problems. The best approach from the security viewpoint is to build a cryptographic database using only homomorphic encryption. An obstacle to this is insufficient efficiency of the existing homomorphic encryption schemes and incomplete solution of a set of issues related to ensuring the confidentiality of decisions making in an untrusted environment. In this paper, we propose the techniques for solving these problems, in particular for organization of execution arbitrary secure query to the encrypted relational database using fully homomorphic encryption. Also we propose a model of query condition that splits query into atomic predicates and linking condition. One of roposed technique is aimed at ensuring the security of linking condition of queries, others keep security of atomic predicates. The parameters of the proposed techniques make it possible to implement them using the already existing homomorphic encryption schemes. The proposed techniques can be a basis for building secure cryptographic cloud databases.

  3. A fractal-based image encryption system

    KAUST Repository

    Abd-El-Hafiz, S. K.

    2014-12-01

    This study introduces a novel image encryption system based on diffusion and confusion processes in which the image information is hidden inside the complex details of fractal images. A simplified encryption technique is, first, presented using a single-fractal image and statistical analysis is performed. A general encryption system utilising multiple fractal images is, then, introduced to improve the performance and increase the encryption key up to hundreds of bits. This improvement is achieved through several parameters: feedback delay, multiplexing and independent horizontal or vertical shifts. The effect of each parameter is studied separately and, then, they are combined to illustrate their influence on the encryption quality. The encryption quality is evaluated using different analysis techniques such as correlation coefficients, differential attack measures, histogram distributions, key sensitivity analysis and the National Institute of Standards and Technology (NIST) statistical test suite. The obtained results show great potential compared to other techniques.

  4. Image Encryption Using the Chaotic Josephus Matrix

    Directory of Open Access Journals (Sweden)

    Gelan Yang

    2014-01-01

    Full Text Available This paper presents a new image encryption solution using the chaotic Josephus matrix. It extends the conventional Josephus traversing to a matrix form and proposes a treatment to improve the randomness of this matrix by mixing chaotic maps. It also derives the corresponding encryption primitives controlled by the chaotic Josephus matrix. In this way, it builds up an image encryption system with very high sensitivities in both encryption key and input image. Our simulation results demonstrate that an encrypted image of using this method is very random-like, that is, a uniform-like pixel histogram and very low correlations in adjacent pixels. The design idea of this method is also applicable to data encryption of other types, like audio and video.

  5. Frequency-Hiding Order-Preserving Encryption

    OpenAIRE

    Kerschbaum, Florian

    2015-01-01

    Order-preserving encryption allows encrypting data, while still enabling efficient range queries on the encrypted data. This makes its performance and functionality very suitable for data outsourcing in cloud computing scenarios, but the security of order-preserving is still debatable. We present a scheme that achieves a strictly stronger notion of security than any other scheme so far. The basic idea is to randomize the ciphertexts to hide the frequency of plaintexts. Still, the client stora...

  6. Optical voice encryption based on digital holography.

    Science.gov (United States)

    Rajput, Sudheesh K; Matoba, Osamu

    2017-11-15

    We propose an optical voice encryption scheme based on digital holography (DH). An off-axis DH is employed to acquire voice information by obtaining phase retardation occurring in the object wave due to sound wave propagation. The acquired hologram, including voice information, is encrypted using optical image encryption. The DH reconstruction and decryption with all the correct parameters can retrieve an original voice. The scheme has the capability to record the human voice in holograms and encrypt it directly. These aspects make the scheme suitable for other security applications and help to use the voice as a potential security tool. We present experimental and some part of simulation results.

  7. Optical image transformation and encryption by phase-retrieval-based double random-phase encoding and compressive ghost imaging

    Science.gov (United States)

    Yuan, Sheng; Yang, Yangrui; Liu, Xuemei; Zhou, Xin; Wei, Zhenzhuo

    2018-01-01

    An optical image transformation and encryption scheme is proposed based on double random-phase encoding (DRPE) and compressive ghost imaging (CGI) techniques. In this scheme, a secret image is first transformed into a binary image with the phase-retrieval-based DRPE technique, and then encoded by a series of random amplitude patterns according to the ghost imaging (GI) principle. Compressive sensing, corrosion and expansion operations are implemented to retrieve the secret image in the decryption process. This encryption scheme takes the advantage of complementary capabilities offered by the phase-retrieval-based DRPE and GI-based encryption techniques. That is the phase-retrieval-based DRPE is used to overcome the blurring defect of the decrypted image in the GI-based encryption, and the CGI not only reduces the data amount of the ciphertext, but also enhances the security of DRPE. Computer simulation results are presented to verify the performance of the proposed encryption scheme.

  8. Encryption techniques to the design of e-beam-generated digital pixel hologram for anti-counterfeiting

    Science.gov (United States)

    Chan, Hau P.; Bao, Nai-Keng; Kwok, Wing O.; Wong, Wing H.

    2002-04-01

    The application of Digital Pixel Hologram (DPH) as anti-counterfeiting technology for products such as commercial goods, credit cards, identity cards, paper money banknote etc. is growing important nowadays. It offers many advantages over other anti-counterfeiting tools and this includes high diffraction effect, high resolving power, resistance to photo copying using two-dimensional Xeroxes, potential for mass production of patterns at a very low cost. Recently, we have successfully in fabricating high definition DPH with resolution higher than 2500dpi for the purpose of anti-counterfeiting by applying modern optical diffraction theory to computer pattern generation technique with the assist of electron beam lithography (EBL). In this paper, we introduce five levels of encryption techniques, which can be embedded in the design of such DPHs to further improve its anti-counterfeiting performance with negligible added on cost. The techniques involved, in the ascending order of decryption complexity, are namely Gray-level Encryption, Pattern Encryption, Character Encryption, Image Modification Encryption and Codebook Encryption. A Hong Kong Special Administration Regions (HKSAR) DPH emblem was fabricated at a resolution of 2540dpi using the facilities housed in our Optoelectronics Research Center. This emblem will be used as an illustration to discuss in details about each encryption idea during the conference.

  9. Different search strategies on encrypted data compared

    NARCIS (Netherlands)

    Brinkman, Richard; Petkovic, M.; Jonker, W.; Jonker, Willem

    When private information is stored in databases that are under the control of others, the only possible way to protect it, is to encrypt it before storing it. In order to efficiently retrieve the data, a search mechanism is needed that still works over the encrypted data. In this chapter an overview

  10. A new chaotic algorithm for image encryption

    International Nuclear Information System (INIS)

    Gao Haojiang; Zhang Yisheng; Liang Shuyun; Li Dequn

    2006-01-01

    Recent researches of image encryption algorithms have been increasingly based on chaotic systems, but the drawbacks of small key space and weak security in one-dimensional chaotic cryptosystems are obvious. This paper presents a new nonlinear chaotic algorithm (NCA) which uses power function and tangent function instead of linear function. Its structural parameters are obtained by experimental analysis. And an image encryption algorithm in a one-time-one-password system is designed. The experimental results demonstrate that the image encryption algorithm based on NCA shows advantages of large key space and high-level security, while maintaining acceptable efficiency. Compared with some general encryption algorithms such as DES, the encryption algorithm is more secure

  11. Image encryption using the fractional wavelet transform

    International Nuclear Information System (INIS)

    Vilardy, Juan M; Useche, J; Torres, C O; Mattos, L

    2011-01-01

    In this paper a technique for the coding of digital images is developed using Fractional Wavelet Transform (FWT) and random phase masks (RPMs). The digital image to encrypt is transformed with the FWT, after the coefficients resulting from the FWT (Approximation, Details: Horizontal, vertical and diagonal) are multiplied each one by different RPMs (statistically independent) and these latest results is applied an Inverse Wavelet Transform (IWT), obtaining the encrypted digital image. The decryption technique is the same encryption technique in reverse sense. This technique provides immediate advantages security compared to conventional techniques, in this technique the mother wavelet family and fractional orders associated with the FWT are additional keys that make access difficult to information to an unauthorized person (besides the RPMs used), thereby the level of encryption security is extraordinarily increased. In this work the mathematical support for the use of the FWT in the computational algorithm for the encryption is also developed.

  12. Orange-spotted grouper (Epinephelus coioides) toll-like receptor 22: molecular characterization, expression pattern and pertinent signaling pathways.

    Science.gov (United States)

    Ding, Xu; Lu, Dan-qi; Hou, Qing-hua; Li, Shui-sheng; Liu, Xiao-chun; Zhang, Yong; Lin, Hao-ran

    2012-09-01

    The toll-like receptors (TLRs) are an important gene family in host innate immunologic surveillance. The TLR22 gene is an essential member of the TLRs that is only found in aquatic animals and has been detected in some bony fish. Here, a TLR22 homolog, EcTLR22, was characterized in the orange-spotted grouper (Epinephelus coioides) via homology cloning. The 3321 bp full-length cDNA sequence of EcTLR22 was obtained, which included an open reading frame of 2880 bp encoding a putative peptide of 960 amino acids containing three highly typical domains with the characteristics of TLR family members. The deduced amino acid sequence of EcTLR22 showed a relatively high similarity to flounder TLR22. Phylogenetic analysis showed that the orange-spotted grouper TLR22 sequence was clustered with those of Perciforme, such as flounder and croaker. Real-time quantitative PCR analysis revealed broad expression of EcTLR22, with relatively high expression detected in the head kidney, trunk kidney, spleen, peripheral blood leukocytes (PBLs) and heart of orange-spotted grouper. After injection with Vibrio alginolyticus, there was significant up-regulation of the expression of EcTLR22 in the spleen. In evaluating unstimulated/stimulated head kidney leukocytes and spleen leukocytes, a significant increase in EcTLR22 mRNA expression was detected, which implied a sensitive immune response. Furthermore, four important molecules for signal transduction, MyD88, TRIF, TNF-α and IRF3, were chosen to analyze the role of the EcTLR22 signaling pathway in anti-pathogen responses. Upon LPS or Poly I:C challenge, expression of the four genes was induced, with an increasing tendency detected in head kidney leukocytes, suggesting that the four genes might work with EcTLR22 in host defense against pathogenic microbes. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. HOMOMORPHIC ENCRYPTION: CLOUD COMPUTING SECURITY AND OTHER APPLICATIONS (A SURVEY

    Directory of Open Access Journals (Sweden)

    A. I. Trubei

    2015-01-01

    Full Text Available Homomorphic encryption is a form of encryption which allows specific types of computations to be carried out on cipher text and to obtain an encrypted result which matches the result of operations performed on the plain text. The article presents a basic concept of the homomorphic encryption and various encryption algorithms in accordance with the fundamental properties of the homomorphic encryption. The examples of various principles and properties of homomorphic encryption, some homomorphic algorithms using asymmetric key systems such as RSA, ElGamal, Paillier algorithms as well as various homomorphic encryption schemes are given. Prospects of homomorphic encryption application in the field of secure cloud computing, electronic voting, cipher text searching, encrypted mail filtering, mobile cipher and secure feedback systems are considered.

  14. Easy encryption for CERN laptops

    CERN Multimedia

    Computer Security Team

    2014-01-01

    The number of laptops stolen from or lost by CERN staff and users is not negligible. On average, four to five devices are reported lost or stolen to the CERN Fire Brigade every month.   The real number might be even higher as not everyone is aware that such thefts/losses should be reported in this way. Along with each laptop, private e-mails and personal documents, as well as MARS forms, contracts, NDAs, etc. are also lost. Fortunately, CERN has not lost any sensitive data so far (unlike other companies). In parallel with the approval by the Enlarged Directorate at its latest session of the development of a CERN-wide Data Protection Policy, the IT Department has prepared measures allowing you to protect the data on your laptop using full hard-disk encryption. While the word “encryption” might sounds complicated, the IT Department has fully automated the encryption process. For centrally managed Windows PCs, you just have to install the corresponding CMF package (“M...

  15. Video Encryption and Decryption on Quantum Computers

    Science.gov (United States)

    Yan, Fei; Iliyasu, Abdullah M.; Venegas-Andraca, Salvador E.; Yang, Huamin

    2015-08-01

    A method for video encryption and decryption on quantum computers is proposed based on color information transformations on each frame encoding the content of the encoding the content of the video. The proposed method provides a flexible operation to encrypt quantum video by means of the quantum measurement in order to enhance the security of the video. To validate the proposed approach, a tetris tile-matching puzzle game video is utilized in the experimental simulations. The results obtained suggest that the proposed method enhances the security and speed of quantum video encryption and decryption, both properties required for secure transmission and sharing of video content in quantum communication.

  16. Age Spots

    Science.gov (United States)

    ... for Every Season How to Choose the Best Skin Care Products In This Section Dermatologic Surgery What is dermatologic ... for Every Season How to Choose the Best Skin Care Products Age Spots Treatment Options Learn more about treatment ...

  17. Pathogenic endoparasites of the spotted seatrout, Cynoscion nebulosus: patterns of infection in estuaries of South Carolina, USA.

    Science.gov (United States)

    Arnott, Stephen A; Dyková, Iva; Roumillat, William A; de Buron, Isaure

    2017-06-01

    Six types of pathogenic endoparasites in an economically important fish, spotted seatrout Cynoscion nebulosus, were studied in order to test whether prevalence of infection and assemblage richness varied with season, host sex, host size, or host age. Fish were collected from South Carolina estuaries, USA, over 12 months (n = 216; total lengths 15-663 mm). They were screened histologically for presence of Henneguya cynoscioni (Myxozoa) and Cardicola spp. (Digenea) in the heart, Kudoa inornata (Myxozoa) in the skeletal muscle, Sinuolinea dimorpha (Myxozoa) in the urinary system, Ichthyophonus sp. (Mesomycetozoea) in the kidney, and an unidentified microsporidian in the liver. Prevalence of infection was 29.8, 38.6, 47.2, 41.2, 13.6, and 2.8%, respectively. All factors had significant, but varying effects on the parasites. Parasite infections were more prevalent in winter than other seasons for Cardicola spp. and H. cynoscioni, more prevalent in winter and spring for Ichthyophonus sp., and more prevalent in male fish than female fish for K. inornata, S. dimorpha, and Ichthyophonus. Prevalence of infection by the three myxosporeans and Cardicola spp. increased with fish length, whereas prevalence of Ichthyophonus increased with length among young fish, but decreased with length among older fish. None of the factors affected the liver microsporidian, although statistical power was low due to its rareness. Assemblage richness varied between 0 and 5, was greater during winter and in male fish, and increased with fish length and fish age. Our results demonstrate that spotted seatrout are commonly co-infected by multiple pathogenic endoparasites, suggesting these parasites likely play an import role in controlling fish population numbers.

  18. 'ISL pattern reserve requirements for today's spot price,' or 'how many in-place pounds are needed for a mining pattern to be profitable in today's market'

    International Nuclear Information System (INIS)

    Anthony, H.L.

    2000-01-01

    Recent uranium spot market values place additional burdens on the geologist and project manager to identify mineralized ore that will yield a profitable return on investment to the mining venture and its investors. The author reviews the various cost components that comprise the total work effort required to produce uranium via ISL methods to arrive at a suitable ore grade that will guarantee profitably. Amortization of costs based on recent expenditures for typical ISL operations are used in conjunction with wellfield development, operating and restoration costs to determine the ore value required to show a positive return on investment. (author)

  19. Encrypted Data Storage in EGEE

    CERN Document Server

    Frohner, Ákos

    2006-01-01

    The medical community is routinely using clinical images and associated medical data for diagnosis, intervention planning and therapy follow-up. Medical imaging is producing an increasing number of digital images for which computerized archiving, processing and analysis are needed. Grids are promising infrastructures for managing and analyzing the huge medical databases. Given the sensitive nature of medical images, practiotionners are often reluctant to use distributed systems though. Security if often implemented by isolating the imaging network from the outside world inside hospitals. Given the wide scale distribution of grid infrastructures and their multiple administrative entities, the level of security for manipulating medical data should be particularly high. In this presentation we describe the architecture of a solution, the gLite Encrypted Data Storage (EDS), which was developed in the framework of Enabling Grids for E-sciencE (EGEE), a project of the European Commission (contract number INFSO--508...

  20. Cracking Advanced Encryption Standard-A Review

    Directory of Open Access Journals (Sweden)

    Jashnil Kumar

    2017-07-01

    Full Text Available Password protection is a major security concern the world is facing today. While there are many publications available that discuss ways to protect passwords and data how widely user from around the world adhere to these rules are unknown. The novelty of this study is that this is the first time a review is done on software tools that can be used to crack Advanced Encryption Standards. Firstly the study does a review on top 10 software tools that are available to crack Advanced Encryption Standards. After which an analysis on two software tools was performed to see how long each software tool took to crack a password. The result of the study gives Advanced Encryption Standard researcher Network security researcher and the general public helpful information on how to strengthen advanced encryption standards and strengthen passwords that are hard for the software tools discussed above to crack.

  1. Efficient multimedia encryption via entropy codec design

    Science.gov (United States)

    Wu, Chung-Ping; Kuo, C.-C. Jay

    2001-08-01

    Efficient encryption algorithms are essential to multimedia data security, since the data size is large and real-time processing is often required. After discussing limitations of previous work on multimedia encryption, we propose a novel methodology for confidentiality, which turns entropy coders into encryption ciphers by using multiple statistical models. The choice of statistical models and the order in which they are applied are kept secret as the key Two encryption schemes are constructed by applying this methodology to the Huffman coder and the QM coder. It is shown that security is achieved without sacrificing the compression performance and the computational speed. The schemes can be applied to most modern compression systems such as MPEG audio, MPEG video and JPEG/JPEG2000 image compression.

  2. Quantum Secure Dialogue with Quantum Encryption

    International Nuclear Information System (INIS)

    Ye Tian-Yu

    2014-01-01

    How to solve the information leakage problem has become the research focus of quantum dialogue. In this paper, in order to overcome the information leakage problem in quantum dialogue, a novel approach for sharing the initial quantum state privately between communicators, i.e., quantum encryption sharing, is proposed by utilizing the idea of quantum encryption. The proposed protocol uses EPR pairs as the private quantum key to encrypt and decrypt the traveling photons, which can be repeatedly used after rotation. Due to quantum encryption sharing, the public announcement on the state of the initial quantum state is omitted, thus the information leakage problem is overcome. The information-theoretical efficiency of the proposed protocol is nearly 100%, much higher than previous information leakage resistant quantum dialogue protocols. Moreover, the proposed protocol only needs single-photon measurements and nearly uses single photons as quantum resource so that it is convenient to implement in practice. (general)

  3. Chaos-based image encryption algorithm

    International Nuclear Information System (INIS)

    Guan Zhihong; Huang Fangjun; Guan Wenjie

    2005-01-01

    In this Letter, a new image encryption scheme is presented, in which shuffling the positions and changing the grey values of image pixels are combined to confuse the relationship between the cipher-image and the plain-image. Firstly, the Arnold cat map is used to shuffle the positions of the image pixels in the spatial-domain. Then the discrete output signal of the Chen's chaotic system is preprocessed to be suitable for the grayscale image encryption, and the shuffled image is encrypted by the preprocessed signal pixel by pixel. The experimental results demonstrate that the key space is large enough to resist the brute-force attack and the distribution of grey values of the encrypted image has a random-like behavior

  4. Multidimensional data encryption with virtual optics

    Science.gov (United States)

    Yu, Lingfeng

    Information security is very important in many application areas in the field of information technology. Recently, a number of optical encryption methods have been proposed for the purpose of information hiding and data security, because optical information processing techniques have obvious advantages such as high degrees of freedom (e.g. amplitude, phase, polarization, wavelength) for encryption and decryption, and high-level data security. However, the limitations of current optical encryption methods relate to the complexity of their optical hardware, the requirements of the information type, lack of flexibility, and the lack of compact and low-cost optoelectronics devices and systems. These problems make it difficult to move optical encryption out of the research lab and into real world application areas. In this thesis, a novel parameterized multidimensional data encryption method based on the concept of "virtual optics" is proposed. A strong motivation for the research in this thesis is to overcome the abovementioned problems currently existing in optical encryption and to retain most of the favorable features of optical encryption. The phrase "virtual optics" means that both the optical encryption and decryption processes are implemented in an all-digital manner, adopting optical information processing technologies such as optical holography, optical diffraction or other relevant optical processes. In addition to utilizing some geometric and physical parameters derived from a configuration of digital optics, some information disarrangement actions have also been suggested as tools for designing multiple locks and keys for data encryption in hyperspace. The sensitivities of these supposed keys are quantitatively analyzed and the possible security level of the proposed cryptosystem is assessed. Security of the cryptosystem is also analyzed by examining some possible attacks on the cryptosystem from the viewpoint of a cryptanalysis. This thesis has shown the

  5. Enhanced Tiny Encryption Algorithm with Embedding (ETEA)

    OpenAIRE

    Virmani, Deepali; Beniwal, Nidhi; Mandal, Gargi; Talwar, Saloni

    2013-01-01

    As computer systems become more pervasive and complex, security is increasingly important. Secure Transmission refers to the transfer of data such as confidential or proprietary information over a secure channel. Many secure transmission methods require a type of encryption. Secure transmissions are put in place to prevent attacks such as ARP spoofing and general data loss. Hence, in order to provide a better security mechanism, in this paper we propose Enhanced Tiny Encryption Algorithm with...

  6. Secret Sharing Schemes and Advanced Encryption Standard

    Science.gov (United States)

    2015-09-01

    Secret Sharing Scheme, they have only been better under certain parameters; there is always a trade -off with some parameter of the scheme. xiv...NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS SECRET SHARING SCHEMES AND ADVANCED ENCRYPTION STANDARD by Bing Yong Lim September 2015 Thesis...AND SUBTITLE SECRET SHARING SCHEMES AND ADVANCED ENCRYPTION STANDARD 5. FUNDING NUMBERS 6. AUTHOR(S) Lim, Bin Yong 7. PERFORMING ORGANIZATION NAME(S

  7. Binary DNA Nanostructures for Data Encryption

    OpenAIRE

    Halvorsen, Ken; Wong, Wesley P.

    2012-01-01

    We present a simple and secure system for encrypting and decrypting information using DNA self-assembly. Binary data is encoded in the geometry of DNA nanostructures with two distinct conformations. Removing or leaving out a single component reduces these structures to an encrypted solution of ssDNA, whereas adding back this missing "decryption key" causes the spontaneous formation of the message through self-assembly, enabling rapid read out via gel electrophoresis. Applications include auth...

  8. Binary DNA nanostructures for data encryption.

    Science.gov (United States)

    Halvorsen, Ken; Wong, Wesley P

    2012-01-01

    We present a simple and secure system for encrypting and decrypting information using DNA self-assembly. Binary data is encoded in the geometry of DNA nanostructures with two distinct conformations. Removing or leaving out a single component reduces these structures to an encrypted solution of ssDNA, whereas adding back this missing "decryption key" causes the spontaneous formation of the message through self-assembly, enabling rapid read out via gel electrophoresis. Applications include authentication, secure messaging, and barcoding.

  9. Mapping the irrigated rice cropping patterns of the Mekong delta, Vietnam through hyper-temporal SPOT NDVI image analysis

    NARCIS (Netherlands)

    Nguyen, Thi Thu Ha; Bie, de C.A.J.M.; Ali, A.; Smaling, E.M.A.; Hoanh, C.T.

    2012-01-01

    Successful identification and mapping of different cropping patterns under cloudy conditions of a specific crop through remote sensing provides important baseline information for planning and monitoring. In Vietnam, this information is either missing or unavailable; several ongoing projects studying

  10. Mapping the irrigated rice cropping patterns of the Mekong delta, Vietnam, through hyper - temporal SPOT NDVI image analysis

    NARCIS (Netherlands)

    Nguyen, Thi Thu Ha; de Bie, C.A.J.M.; Ali, A.; Smaling, E.M.A.

    2012-01-01

    Successful identification and mapping of different cropping patterns under cloudy conditions of a specific crop through remote sensing provides important baseline information for planning and monitoring. In Vietnam, this information is either missing or unavailable; several ongoing projects studying

  11. Emergence time and skin melanin spot patterns do not correlate with growth performance, social competitive ability or stress response in farmed rainbow trout

    DEFF Research Database (Denmark)

    Gesto, Manuel; Skov, Peter Vilhelm; Jokumsen, Alfred

    2017-01-01

    at a later stage. Apart from aggression and dominance, other behavioral and metabolic traits, such as boldness, metabolic rate, or growth, have also been linked to emergence time. Altogether, the traits of early- and late-emerging fish resemble those of the proactive and reactive stress-coping style....... In the present study, eyed eggs from a commercial supplier were hatched, and larvae fractionated according to their emergence time. Later on, juvenile fish from different emergence fractions were subjected to a stress challenge and also tested to evaluate their competitive ability for food. Beyond some slight...... dissimilarities in the acute stress responses, emergence fraction displayed no correlation with growth rates, or the ability to compete for feed. Within the whole group of fish utilized in the experiments, no relationship between skinmelanin spot pattern and growth performance, stress response intensity...

  12. SPOT Program

    Science.gov (United States)

    Smith, Jason T.; Welsh, Sam J.; Farinetti, Antonio L.; Wegner, Tim; Blakeslee, James; Deboeck, Toni F.; Dyer, Daniel; Corley, Bryan M.; Ollivierre, Jarmaine; Kramer, Leonard; hide

    2010-01-01

    A Spacecraft Position Optimal Tracking (SPOT) program was developed to process Global Positioning System (GPS) data, sent via telemetry from a spacecraft, to generate accurate navigation estimates of the vehicle position and velocity (state vector) using a Kalman filter. This program uses the GPS onboard receiver measurements to sequentially calculate the vehicle state vectors and provide this information to ground flight controllers. It is the first real-time ground-based shuttle navigation application using onboard sensors. The program is compact, portable, self-contained, and can run on a variety of UNIX or Linux computers. The program has a modular objec-toriented design that supports application-specific plugins such as data corruption remediation pre-processing and remote graphics display. The Kalman filter is extensible to additional sensor types or force models. The Kalman filter design is also strong against data dropouts because it uses physical models from state and covariance propagation in the absence of data. The design of this program separates the functionalities of SPOT into six different executable processes. This allows for the individual processes to be connected in an a la carte manner, making the feature set and executable complexity of SPOT adaptable to the needs of the user. Also, these processes need not be executed on the same workstation. This allows for communications between SPOT processes executing on the same Local Area Network (LAN). Thus, SPOT can be executed in a distributed sense with the capability for a team of flight controllers to efficiently share the same trajectory information currently being computed by the program. SPOT is used in the Mission Control Center (MCC) for Space Shuttle Program (SSP) and International Space Station Program (ISSP) operations, and can also be used as a post -flight analysis tool. It is primarily used for situational awareness, and for contingency situations.

  13. Dark Spots

    Science.gov (United States)

    2006-01-01

    Dark spots (left) and 'fans' appear to scribble dusty hieroglyphics on top of the Martian south polar cap in two high-resolution Mars Global Surveyor, Mars Orbiter Camera images taken in southern spring. Each image is about 3-kilometers wide (2-miles).

  14. Emergence Time and Skin Melanin Spot Patterns Do Not Correlate with Growth Performance, Social Competitive Ability or Stress Response in Farmed Rainbow Trout

    Directory of Open Access Journals (Sweden)

    Manuel Gesto

    2017-06-01

    Full Text Available In wild salmonid fish, specific individual behavioral traits have been correlated with the timing of fry emergence from their gravel spawning nests; Early emerging fish display more aggressive behavior and have a higher probability of becoming socially dominant, compared to fish that emerge at a later stage. Apart from aggression and dominance, other behavioral and metabolic traits, such as boldness, metabolic rate, or growth, have also been linked to emergence time. Altogether, the traits of early- and late-emerging fish resemble those of the proactive and reactive stress-coping style, respectively. As proactive fish are considered more resilient to stress, it may be desirable to select these for aquaculture production. However, it is currently unclear to what extent the link between emergence time and stress-coping styles is maintained in the selective breeding of farmed fish. In the present study, eyed eggs from a commercial supplier were hatched, and larvae fractionated according to their emergence time. Later on, juvenile fish from different emergence fractions were subjected to a stress challenge and also tested to evaluate their competitive ability for food. Beyond some slight dissimilarities in the acute stress responses, emergence fraction displayed no correlation with growth rates, or the ability to compete for feed. Within the whole group of fish utilized in the experiments, no relationship between skin melanin spot pattern and growth performance, stress response intensity, or competitive ability was found. Altogether, the differences in physiological traits related to emergence time were not as strong as those found in earlier studies. It is hypothesized, that the origin and degree of domestication of the fish might be partly responsible for this. The predictive value of skin spots or emergence time to infer the fish stress coping style in farmed fish is also discussed.

  15. A Survey of Image Encryption Algorithms

    Science.gov (United States)

    Kumari, Manju; Gupta, Shailender; Sardana, Pranshul

    2017-12-01

    Security of data/images is one of the crucial aspects in the gigantic and still expanding domain of digital transfer. Encryption of images is one of the well known mechanisms to preserve confidentiality of images over a reliable unrestricted public media. This medium is vulnerable to attacks and hence efficient encryption algorithms are necessity for secure data transfer. Various techniques have been proposed in literature till date, each have an edge over the other, to catch-up to the ever growing need of security. This paper is an effort to compare the most popular techniques available on the basis of various performance metrics like differential, statistical and quantitative attacks analysis. To measure the efficacy, all the modern and grown-up techniques are implemented in MATLAB-2015. The results show that the chaotic schemes used in the study provide highly scrambled encrypted images having uniform histogram distribution. In addition, the encrypted images provided very less degree of correlation coefficient values in horizontal, vertical and diagonal directions, proving their resistance against statistical attacks. In addition, these schemes are able to resist differential attacks as these showed a high sensitivity for the initial conditions, i.e. pixel and key values. Finally, the schemes provide a large key spacing, hence can resist the brute force attacks, and provided a very less computational time for image encryption/decryption in comparison to other schemes available in literature.

  16. Image encryption using the Sudoku matrix

    Science.gov (United States)

    Wu, Yue; Zhou, Yicong; Noonan, Joseph P.; Panetta, Karen; Agaian, Sos

    2010-04-01

    This paper introduces a new effective and lossless image encryption algorithm using a Sudoku Matrix to scramble and encrypt the image. The new algorithm encrypts an image through a three stage process. In the first stage, a reference Sudoku matrix is generated as the foundation for the encryption and scrambling processes. The image pixels' intensities are then changed by using the reference Sudoku matrix values, and then the pixels' positions are shuffled using the Sudoku matrix as a mapping process. The advantages of this method is useful for efficiently encrypting a variety of digital images, such as binary images, gray images, and RGB images without any quality loss. The security keys of the presented algorithm are the combination of the parameters in a 1D chaotic logistic map, a parameter to control the size of Sudoku Matrix and the number of iteration times desired for scrambling. The possible security key space is extremely large. The principles of the presented scheme could be applied to provide security for a variety of systems including image, audio and video systems.

  17. Topological charge number multiplexing for JTC multiple-image encryption

    Science.gov (United States)

    Chen, Qi; Shen, Xueju; Dou, Shuaifeng; Lin, Chao; Wang, Long

    2018-04-01

    We propose a method of topological charge number multiplexing based on the JTC encryption system to achieve multiple-image encryption. Using this method, multi-image can be encrypted into single ciphertext, and the original images can be recovered according to the authority level. The number of encrypted images is increased, moreover, the quality of decrypted images is improved. Results of computer simulation and initial experiment identify the validity of our proposed method.

  18. Parallel image encryption algorithm based on discretized chaotic map

    International Nuclear Information System (INIS)

    Zhou Qing; Wong Kwokwo; Liao Xiaofeng; Xiang Tao; Hu Yue

    2008-01-01

    Recently, a variety of chaos-based algorithms were proposed for image encryption. Nevertheless, none of them works efficiently in parallel computing environment. In this paper, we propose a framework for parallel image encryption. Based on this framework, a new algorithm is designed using the discretized Kolmogorov flow map. It fulfills all the requirements for a parallel image encryption algorithm. Moreover, it is secure and fast. These properties make it a good choice for image encryption on parallel computing platforms

  19. Type-based Proxy Re-encryption and its Construction

    NARCIS (Netherlands)

    Tang, Qiang

    Recently, the concept of proxy re-encryption has been shown very useful in a number of applications, especially in enforcing access control policies. In existing proxy re-encryption schemes, the delegatee can decrypt all ciphertexts targeted to the delegator after re-encryption by the proxy.

  20. Type-Based Proxy Re-encryption and Its Construction

    NARCIS (Netherlands)

    Tang, Qiang

    2008-01-01

    Recently, the concept of proxy re-encryption has been shown very useful in a number of applications, especially in enforcing access control policies. In existing proxy re-encryption schemes, the delegatee can decrypt all ciphertexts for the delegator after re-encryption by the proxy. Consequently,

  1. Generic Adaptively Secure Searchable Phrase Encryption

    Directory of Open Access Journals (Sweden)

    Kissel Zachary A.

    2017-01-01

    Full Text Available In recent years searchable symmetric encryption has seen a rapid increase in query expressiveness including keyword, phrase, Boolean, and fuzzy queries. With this expressiveness came increasingly complex constructions. Having these facts in mind, we present an efficient and generic searchable symmetric encryption construction for phrase queries. Our construction is straightforward to implement, and is proven secure under adaptively chosen query attacks (CQA2 in the random oracle model with an honest-but-curious adversary. To our knowledge, this is the first encrypted phrase search system that achieves CQA2 security. Moreover, we demonstrate that our document collection preprocessing algorithm allows us to extend a dynamic SSE construction so that it supports phrase queries. We also provide a compiler theorem which transforms any CQA2-secure SSE construction for keyword queries into a CQA2-secure SSE construction that supports phrase queries.

  2. Frontpage and Dreamweaver users must use encryption

    CERN Multimedia

    Web Services

    2006-01-01

    In order to ensure document confidentiality and protect users from the possible theft of their passwords, all web authoring actions will be required to use encryption as of 15 February 2006. Most Frontpage and Dreamweaver users will have to slightly change the way they connect to their web sites in order to enable encryption. Please note that only the initial connection to the web site from Frontpage or Dreamweaver is affected: there is no change in the use of these applications after the initial connection, and the web site itself is not affected. Further details, as well as instructions on how to enable encryption, are available at: http://cern.ch/web/docs/AuthDoc/SecureAuthoring. In case of problems, please contact the computer helpdesk or web.support@cern.ch. The Web Services Team

  3. Cracking Advanced Encryption Standard-A Review

    OpenAIRE

    Jashnil Kumar; Mohammed Farik

    2017-01-01

    Password protection is a major security concern the world is facing today. While there are many publications available that discuss ways to protect passwords and data how widely user from around the world adhere to these rules are unknown. The novelty of this study is that this is the first time a review is done on software tools that can be used to crack Advanced Encryption Standards. Firstly the study does a review on top 10 software tools that are available to crack Advanced Encryption Sta...

  4. Multimedia encryption and authentication techniques and applications

    CERN Document Server

    Furht, Borko

    2006-01-01

    Intellectual property owners must continually exploit new ways of reproducing, distributing, and marketing their products. However, the threat of piracy looms as a major problem with digital distribution and storage technologies. Multimedia Encryption and Authentication Techniques and Applications covers current and future trends in the design of modern systems that use encryption and authentication to protect multimedia content. Containing the works of contributing authors who are worldwide experts in their fields, this volume is intended for researchers and practitioners, as well as for thos

  5. Binary DNA nanostructures for data encryption.

    Directory of Open Access Journals (Sweden)

    Ken Halvorsen

    Full Text Available We present a simple and secure system for encrypting and decrypting information using DNA self-assembly. Binary data is encoded in the geometry of DNA nanostructures with two distinct conformations. Removing or leaving out a single component reduces these structures to an encrypted solution of ssDNA, whereas adding back this missing "decryption key" causes the spontaneous formation of the message through self-assembly, enabling rapid read out via gel electrophoresis. Applications include authentication, secure messaging, and barcoding.

  6. Swimming with the giant: coexistence patterns of a new redfin minnowPseudobarbus skeltonifrom a global biodiversity hot spot.

    Science.gov (United States)

    Kadye, Wilbert T; Chakona, Albert; Jordaan, Martine S

    2016-10-01

    Ecological niche theory predicts that coexistence is facilitated by resource partitioning mechanisms that are influenced by abiotic and biotic interactions. Alternative hypotheses suggest that under certain conditions, species may become phenotypically similar and functionally equivalent, which invokes the possibility of other mechanisms, such as habitat filtering processes. To test these hypotheses, we examined the coexistence of the giant redfin Pseudobarbus skeltoni , a newly described freshwater fish, together with its congener Pseudobabus burchelli and an anabantid Sandelia capensis by assessing their scenopoetic and bionomic patterns. We found high habitat and isotope niche overlaps between the two redfins, rendering niche partitioning a less plausible sole mechanism that drives their coexistence. By comparison, environment-trait relationships revealed differences in species-environment relationships, making habitat filtering and functional equivalence less likely alternatives. Based on P. skeltoni 's high habitat niche overlap with other species, and its large isotope niche width, we inferred the likelihood of differential resource utilization at trophic level as an alternative mechanism that distinguished it from its congener. In comparison, its congener P. burchelli appeared to have a relatively small trophic niche, suggesting that its trophic niche was more conserved despite being the most abundant species. By contrast, S. capensis was distinguished by occupying a higher trophic position and by having a trophic niche that had a low probability of overlapping onto those of redfins. Therefore, trophic niche partitioning appeared to influence the coexistence between S. capensis and redfins. This study suggests that coexistence of these fishes appears to be promoted by their differences in niche adaptation mechanisms that are probably shaped by historic evolutionary and ecological processes.

  7. Identity-Based Verifiably Encrypted Signatures without Random Oracles

    Science.gov (United States)

    Zhang, Lei; Wu, Qianhong; Qin, Bo

    Fair exchange protocol plays an important role in electronic commerce in the case of exchanging digital contracts. Verifiably encrypted signatures provide an optimistic solution to these scenarios with an off-line trusted third party. In this paper, we propose an identity-based verifiably encrypted signature scheme. The scheme is non-interactive to generate verifiably encrypted signatures and the resulting encrypted signature consists of only four group elements. Based on the computational Diffie-Hellman assumption, our scheme is proven secure without using random oracles. To the best of our knowledge, this is the first identity-based verifiably encrypted signature scheme provably secure in the standard model.

  8. Influence of primary prey on home-range size and habitat-use patterns of northern spotted owls (Strix occidentalis caurina)

    Science.gov (United States)

    Cynthia J. Zabel; Kevin S. McKelvey; James P. Ward

    1995-01-01

    Correlations between the home-range size of northern spotted owls (Strix occidentalis caurina) and proportion of their range in old-growth forest have been reported, but there are few data on the relationship between their home-range size and prey. The primary prey of spotted owls are wood rats and northern flying squirrels (Glaucomys sabrinus). Wood...

  9. QR code optical encryption using spatially incoherent illumination

    Science.gov (United States)

    Cheremkhin, P. A.; Krasnov, V. V.; Rodin, V. G.; Starikov, R. S.

    2017-02-01

    Optical encryption is an actively developing field of science. The majority of encryption techniques use coherent illumination and suffer from speckle noise, which severely limits their applicability. The spatially incoherent encryption technique does not have this drawback, but its effectiveness is dependent on the Fourier spectrum properties of the image to be encrypted. The application of a quick response (QR) code in the capacity of a data container solves this problem, and the embedded error correction code also enables errorless decryption. The optical encryption of digital information in the form of QR codes using spatially incoherent illumination was implemented experimentally. The encryption is based on the optical convolution of the image to be encrypted with the kinoform point spread function, which serves as an encryption key. Two liquid crystal spatial light modulators were used in the experimental setup for the QR code and the kinoform imaging, respectively. The quality of the encryption and decryption was analyzed in relation to the QR code size. Decryption was conducted digitally. The successful decryption of encrypted QR codes of up to 129  ×  129 pixels was demonstrated. A comparison with the coherent QR code encryption technique showed that the proposed technique has a signal-to-noise ratio that is at least two times higher.

  10. MATRIX ALGORITHMS OF ENCRYPTIC PROTECTION OF INFORMATION AND EXCHANGE OF ENCRYPTION KEY

    Directory of Open Access Journals (Sweden)

    A. Beletsky

    2010-07-01

    Full Text Available The algorithms of the exchange of encryption keys between users of computer networks and cryptographic protection of information transmitted over open communications channels. The algorithm is based a modified asymmetric protocol Diffie-Hellman (DH. The essence of the modification amounts to the replacement of large prime numbers algorithm DH guaranteed nonsingular n-complete binary matrices of high order. The methods of synthesis of these matrices. Discussed ways to counter attacks on the encryption algorithm.

  11. Test and Verification of AES Used for Image Encryption

    Science.gov (United States)

    Zhang, Yong

    2018-03-01

    In this paper, an image encryption program based on AES in cipher block chaining mode was designed with C language. The encryption/decryption speed and security performance of AES based image cryptosystem were tested and used to compare the proposed cryptosystem with some existing image cryptosystems based on chaos. Simulation results show that AES can apply to image encryption, which refutes the widely accepted point of view that AES is not suitable for image encryption. This paper also suggests taking the speed of AES based image encryption as the speed benchmark of image encryption algorithms. And those image encryption algorithms whose speeds are lower than the benchmark should be discarded in practical communications.

  12. An end to end secure CBIR over encrypted medical database.

    Science.gov (United States)

    Bellafqira, Reda; Coatrieux, Gouenou; Bouslimi, Dalel; Quellec, Gwenole

    2016-08-01

    In this paper, we propose a new secure content based image retrieval (SCBIR) system adapted to the cloud framework. This solution allows a physician to retrieve images of similar content within an outsourced and encrypted image database, without decrypting them. Contrarily to actual CBIR approaches in the encrypted domain, the originality of the proposed scheme stands on the fact that the features extracted from the encrypted images are themselves encrypted. This is achieved by means of homomorphic encryption and two non-colluding servers, we however both consider as honest but curious. In that way an end to end secure CBIR process is ensured. Experimental results carried out on a diabetic retinopathy database encrypted with the Paillier cryptosystem indicate that our SCBIR achieves retrieval performance as good as if images were processed in their non-encrypted form.

  13. A one-time pad encryption method combining full-phase image encryption and hiding

    Science.gov (United States)

    Li, Jiaosheng; Xiong, Jiaxiang; Zhang, Qinnan; Zhong, Liyun; Zhou, Yunfei; Li, Jun; Lu, Xiaoxu

    2017-08-01

    A one-time pad encryption method combining full-phase image encryption and hiding is proposed. Firstly, original images are encoded in the phase and encrypted by phase keys loaded on the phase-only liquid crystal spatial light modulator, where the phase keys can be distributed using a quantum key distribution method. Subsequently, a host image is introduced to produce a reference wave, and overlap with an object wave to form an interferogram. Finally, based on phase-shifting interferometry, we can achieve the above encrypted image hiding. Both the simulation and experiment research demonstrate the feasibility of the proposed method, meanwhile the key and the encrypted image can be changed randomly, so the proposed system reveals the high flexibility, anti-attack ability and can be used to implement the one-time pad to achieve absolute secure transmission with the quantum key distribution method. Moreover, system security will be improved due to the fact that encryption information hidden in the host image can be treated as background noise, which does not attract the attention of the attacker.

  14. Mongolian spots

    Directory of Open Access Journals (Sweden)

    Divya Gupta

    2013-01-01

    Full Text Available Mongolian spots (MS are birthmarks that are present at birth and their most common location is sacrococcygeal or lumbar area. Lesions may be single or multiple and usually involve < 5% total body surface area. They are macular and round, oval or irregular in shape. The color varies from blue to greenish, gray, black or a combination of any of the above. The size varies from few to more than 20 centimetres. Pigmentation is most intense at the age of one year and gradually fades thereafter. It is rarely seen after the age of 6 years. Aberrant MS over occiput, temple, mandibular area, shoulders and limbs may be confused with other dermal melanocytoses and bruises secondary to child abuse, thus necessitating documentation at birth. Although regarded as benign, recent data suggest that MS may be associated with inborn errors of metabolism and neurocristopathies. Mongolian spots usually resolve by early childhood and hence no treatment is generally needed if they are located in the sacral area. However, sometimes it may be required for extrasacral lesions for cosmesis.

  15. Image Encryption and Chaotic Cellular Neural Network

    Science.gov (United States)

    Peng, Jun; Zhang, Du

    Machine learning has been playing an increasingly important role in information security and assurance. One of the areas of new applications is to design cryptographic systems by using chaotic neural network due to the fact that chaotic systems have several appealing features for information security applications. In this chapter, we describe a novel image encryption algorithm that is based on a chaotic cellular neural network. We start by giving an introduction to the concept of image encryption and its main technologies, and an overview of the chaotic cellular neural network. We then discuss the proposed image encryption algorithm in details, which is followed by a number of security analyses (key space analysis, sensitivity analysis, information entropy analysis and statistical analysis). The comparison with the most recently reported chaos-based image encryption algorithms indicates that the algorithm proposed in this chapter has a better security performance. Finally, we conclude the chapter with possible future work and application prospects of the chaotic cellular neural network in other information assurance and security areas.

  16. Dynamic Rule Encryption for Mobile Payment

    Directory of Open Access Journals (Sweden)

    Emir Husni

    2017-01-01

    Full Text Available The trend of financial transactions by using a mobile phone or mobile payment increases. By using the mobile payment service, users can save money on mobile phone (handset and separate from the pulse. For protecting users, mobile payment service providers must complete the mobile payment service with the transaction security. One way to provide transaction security is to utilize a secure mobile payment application. This research provides a safety feature used for an Android-based mobile payment application. This security feature is making encryption rules dynamically named Dynamic Rule Encryption (DRE. DRE has the ability to protect data by means of encrypting data with dynamic rules, and DRE also has a token function for an authentication. DRE token raised with dynamic time-based rules. Here, the time is used as a reference with the order of the day in the year (day of the year. The processes of the DRE’s encryption, decryption, and the DRE’s functionality as the token are discussed in this paper. Here, the Hamming distance metric is employed for having maximum differences between plaintext and ciphertext.

  17. A Verifiable Secret Shuffle of Homomorphic Encryptions

    DEFF Research Database (Denmark)

    Groth, Jens

    2003-01-01

    We show how to prove in honest verifier zero-knowledge the correctness of a shuffle of homomorphic encryptions (or homomorphic commitments.) A shuffle consists in a rearrangement of the input ciphertexts and a reencryption of them so that the permutation is not revealed....

  18. Efficient Tree Search in Encrypted Data

    NARCIS (Netherlands)

    Brinkman, Richard; Feng, L.; Doumen, J.M.; Hartel, Pieter H.; Jonker, Willem

    Sometimes there is a need to store sensitive data on an untrusted database server. Song Wagner and Perrig have introduced a way to search for the existence of a word in an encrypted textual document. The search speed is linear in the size of the document. It does not scale well for a large database.

  19. Efficient Tree Search in Encrypted Data

    NARCIS (Netherlands)

    Brinkman, Richard; Fernández-Medina, E.; Hernández Castro, J.C.; Feng, L.; Doumen, J.M.; García-Villalba, L.J.; Hartel, Pieter H.; Jonker, Willem

    Sometimes there is a need to store sensitive data on an untrusted database server. Song, Wagner and Perrig have introduced a way to search for the existence of a word in an encrypted textual document. The search speed is linear in the size of the document. It does not scale well for a large

  20. 47 CFR 90.553 - Encryption.

    Science.gov (United States)

    2010-10-01

    ... January 23, 2001, Telecommunications Industry Association, ANSI/TIA/EIA-102.AAAA-A-2001. (c) The Director... 47 Telecommunication 5 2010-10-01 2010-10-01 false Encryption. 90.553 Section 90.553 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND...

  1. FPGA BASED HARDWARE KEY FOR TEMPORAL ENCRYPTION

    Directory of Open Access Journals (Sweden)

    B. Lakshmi

    2010-09-01

    Full Text Available In this paper, a novel encryption scheme with time based key technique on an FPGA is presented. Time based key technique ensures right key to be entered at right time and hence, vulnerability of encryption through brute force attack is eliminated. Presently available encryption systems, suffer from Brute force attack and in such a case, the time taken for breaking a code depends on the system used for cryptanalysis. The proposed scheme provides an effective method in which the time is taken as the second dimension of the key so that the same system can defend against brute force attack more vigorously. In the proposed scheme, the key is rotated continuously and four bits are drawn from the key with their concatenated value representing the delay the system has to wait. This forms the time based key concept. Also the key based function selection from a pool of functions enhances the confusion and diffusion to defend against linear and differential attacks while the time factor inclusion makes the brute force attack nearly impossible. In the proposed scheme, the key scheduler is implemented on FPGA that generates the right key at right time intervals which is then connected to a NIOS – II processor (a virtual microcontroller which is brought out from Altera FPGA that communicates with the keys to the personal computer through JTAG (Joint Test Action Group communication and the computer is used to perform encryption (or decryption. In this case the FPGA serves as hardware key (dongle for data encryption (or decryption.

  2. Attribute-Based Proxy Re-Encryption with Keyword Search

    Science.gov (United States)

    Shi, Yanfeng; Liu, Jiqiang; Han, Zhen; Zheng, Qingji; Zhang, Rui; Qiu, Shuo

    2014-01-01

    Keyword search on encrypted data allows one to issue the search token and conduct search operations on encrypted data while still preserving keyword privacy. In the present paper, we consider the keyword search problem further and introduce a novel notion called attribute-based proxy re-encryption with keyword search (), which introduces a promising feature: In addition to supporting keyword search on encrypted data, it enables data owners to delegate the keyword search capability to some other data users complying with the specific access control policy. To be specific, allows (i) the data owner to outsource his encrypted data to the cloud and then ask the cloud to conduct keyword search on outsourced encrypted data with the given search token, and (ii) the data owner to delegate other data users keyword search capability in the fine-grained access control manner through allowing the cloud to re-encrypted stored encrypted data with a re-encrypted data (embedding with some form of access control policy). We formalize the syntax and security definitions for , and propose two concrete constructions for : key-policy and ciphertext-policy . In the nutshell, our constructions can be treated as the integration of technologies in the fields of attribute-based cryptography and proxy re-encryption cryptography. PMID:25549257

  3. NES++: number system for encryption based privacy preserving speaker verification

    Science.gov (United States)

    Xu, Lei; Feng, Tao; Zhao, Xi; Shi, Weidong

    2014-05-01

    As speech based operation becomes a main hand-free interaction solution between human and mobile devices (i.e., smartphones, Google Glass), privacy preserving speaker verification receives much attention nowadays. Privacy preserving speaker verification can be achieved through many different ways, such as fuzzy vault and encryption. Encryption based solutions are promising as cryptography is based on solid mathematic foundations and the security properties can be easily analyzed in a well established framework. Most current asymmetric encryption schemes work on finite algebraic structures, such as finite group and finite fields. However, the encryption scheme for privacy preserving speaker verification must handle floating point numbers. This gap must be filled to make the overall scheme practical. In this paper, we propose a number system that meets the requirements of both speaker verification and the encryption scheme used in the process. It also supports addition homomorphic property of Pailliers encryption, which is crucial for privacy preserving speaker verification. As asymmetric encryption is expensive, we propose a method of packing several numbers into one plain-text and the computation overhead is greatly reduced. To evaluate the performance of this method, we implement Pailliers encryption scheme over proposed number system and the packing technique. Our findings show that the proposed solution can fulfill the gap between speaker verification and encryption scheme very well, and the packing technique improves the overall performance. Furthermore, our solution is a building block of encryption based privacy preserving speaker verification, the privacy protection and accuracy rate are not affected.

  4. Quantum Fully Homomorphic Encryption with Verification

    DEFF Research Database (Denmark)

    Alagic, Gorjan; Dulek, Yfke; Schaffner, Christian

    2017-01-01

    Fully-homomorphic encryption (FHE) enables computation on encrypted data while maintaining secrecy. Recent research has shown that such schemes exist even for quantum computation. Given the numerous applications of classical FHE (zero-knowledge proofs, secure two-party computation, obfuscation, etc.......) it is reasonable to hope that quantum FHE (or QFHE) will lead to many new results in the quantum setting. However, a crucial ingredient in almost all applications of FHE is circuit verification. Classically, verification is performed by checking a transcript of the homomorphic computation. Quantumly, this strategy...... is impossible due to no-cloning. This leads to an important open question: can quantum computations be delegated and verified in a non-interactive manner? In this work, we answer this question in the affirmative, by constructing a scheme for QFHE with verification (vQFHE). Our scheme provides authenticated...

  5. Efficient Dynamic Searchable Encryption with Forward Privacy

    Directory of Open Access Journals (Sweden)

    Etemad Mohammad

    2018-01-01

    Full Text Available Searchable symmetric encryption (SSE enables a client to perform searches over its outsourced encrypted files while preserving privacy of the files and queries. Dynamic schemes, where files can be added or removed, leak more information than static schemes. For dynamic schemes, forward privacy requires that a newly added file cannot be linked to previous searches. We present a new dynamic SSE scheme that achieves forward privacy by replacing the keys revealed to the server on each search. Our scheme is efficient and parallelizable and outperforms the best previous schemes providing forward privacy, and achieves competitive performance with dynamic schemes without forward privacy. We provide a full security proof in the random oracle model. In our experiments on the Wikipedia archive of about four million pages, the server takes one second to perform a search with 100,000 results.

  6. Encryption in Chaotic Systems with Sinusoidal Excitations

    Directory of Open Access Journals (Sweden)

    G. Obregón-Pulido

    2014-01-01

    Full Text Available In this contribution an encryption method using a chaotic oscillator, excited by “n” sinusoidal signals, is presented. The chaotic oscillator is excited by a sum of “n” sinusoidal signals and a message. The objective is to encrypt such a message using the chaotic behavior and transmit it, and, as the chaotic system is perturbed by the sinusoidal signal, the transmission security could be increased due to the effect of such a perturbation. The procedure is based on the regulation theory and consider that the receiver knows the frequencies of the perturbing signal, with this considerations the algorithm estimates the excitation in such a way that the receiver can cancel out the perturbation and all the undesirable dynamics in order to produce only the message. In this way we consider that the security level is increased.

  7. New Security Results on Encrypted Key Exchange

    Energy Technology Data Exchange (ETDEWEB)

    Bresson, Emmanuel; Chevassut, Olivier; Pointcheval, David

    2003-12-15

    Schemes for encrypted key exchange are designed to provide two entities communicating over a public network, and sharing a (short) password only, with a session key to be used to achieve data integrity and/or message confidentiality. An example of a very efficient and ''elegant'' scheme for encrypted key exchange considered for standardization by the IEEE P1363 Standard working group is AuthA. This scheme was conjectured secure when the symmetric-encryption primitive is instantiated via either a cipher that closely behaves like an ''ideal cipher,'' or a mask generation function that is the product of the message with a hash of the password. While the security of this scheme in the former case has been recently proven, the latter case was still an open problem. For the first time we prove in this paper that this scheme is secure under the assumptions that the hash function closely behaves like a random oracle and that the computational Diffie-Hellman problem is difficult. Furthermore, since Denial-of-Service (DoS) attacks have become a common threat we enhance AuthA with a mechanism to protect against them.

  8. A hash-based image encryption algorithm

    Science.gov (United States)

    Cheddad, Abbas; Condell, Joan; Curran, Kevin; McKevitt, Paul

    2010-03-01

    There exist several algorithms that deal with text encryption. However, there has been little research carried out to date on encrypting digital images or video files. This paper describes a novel way of encrypting digital images with password protection using 1D SHA-2 algorithm coupled with a compound forward transform. A spatial mask is generated from the frequency domain by taking advantage of the conjugate symmetry of the complex imagery part of the Fourier Transform. This mask is then XORed with the bit stream of the original image. Exclusive OR (XOR), a logical symmetric operation, that yields 0 if both binary pixels are zeros or if both are ones and 1 otherwise. This can be verified simply by modulus (pixel1, pixel2, 2). Finally, confusion is applied based on the displacement of the cipher's pixels in accordance with a reference mask. Both security and performance aspects of the proposed method are analyzed, which prove that the method is efficient and secure from a cryptographic point of view. One of the merits of such an algorithm is to force a continuous tone payload, a steganographic term, to map onto a balanced bits distribution sequence. This bit balance is needed in certain applications, such as steganography and watermarking, since it is likely to have a balanced perceptibility effect on the cover image when embedding.

  9. A privacy-preserving parallel and homomorphic encryption scheme

    Directory of Open Access Journals (Sweden)

    Min Zhaoe

    2017-04-01

    Full Text Available In order to protect data privacy whilst allowing efficient access to data in multi-nodes cloud environments, a parallel homomorphic encryption (PHE scheme is proposed based on the additive homomorphism of the Paillier encryption algorithm. In this paper we propose a PHE algorithm, in which plaintext is divided into several blocks and blocks are encrypted with a parallel mode. Experiment results demonstrate that the encryption algorithm can reach a speed-up ratio at about 7.1 in the MapReduce environment with 16 cores and 4 nodes.

  10. Quantum Encryption Minimising Key Leakage under Known Plaintext Attacks

    DEFF Research Database (Denmark)

    Pedersen, Thomas Brochmann

    2006-01-01

    In this dissertation we show how, by using a quantum channel, we can get more unconditionally secret communication with a symmetric key under known plaintext attacks. In unconditionally secret encryption schemes the key is necessarily an expensive resource since it cannot safely be reused for more......, or interactive encryption schemes, where the interaction does not need to occur online. In our model we show that the amount of key leaked under a known plaintext attack can be made arbitrarily small even in non-interactive encryption schemes. We also give an encryption scheme where eavesdropping can be detected...

  11. Key exchange using biometric identity based encryption for sharing encrypted data in cloud environment

    Science.gov (United States)

    Hassan, Waleed K.; Al-Assam, Hisham

    2017-05-01

    The main problem associated with using symmetric/ asymmetric keys is how to securely store and exchange the keys between the parties over open networks particularly in the open environment such as cloud computing. Public Key Infrastructure (PKI) have been providing a practical solution for session key exchange for loads of web services. The key limitation of PKI solution is not only the need for a trusted third partly (e.g. certificate authority) but also the absent link between data owner and the encryption keys. The latter is arguably more important where accessing data needs to be linked with identify of the owner. Currently available key exchange protocols depend on using trusted couriers or secure channels, which can be subject to man-in-the-middle attack and various other attacks. This paper proposes a new protocol for Key Exchange using Biometric Identity Based Encryption (KE-BIBE) that enables parties to securely exchange cryptographic keys even an adversary is monitoring the communication channel between the parties. The proposed protocol combines biometrics with IBE in order to provide a secure way to access symmetric keys based on the identity of the users in unsecure environment. In the KE-BIOBE protocol, the message is first encrypted by the data owner using a traditional symmetric key before migrating it to a cloud storage. The symmetric key is then encrypted using public biometrics of the users selected by data owner to decrypt the message based on Fuzzy Identity-Based Encryption. Only the selected users will be able to decrypt the message by providing a fresh sample of their biometric data. The paper argues that the proposed solution eliminates the needs for a key distribution centre in traditional cryptography. It will also give data owner the power of finegrained sharing of encrypted data by control who can access their data.

  12. CHAOS-BASED ADVANCED ENCRYPTION STANDARD

    KAUST Repository

    Abdulwahed, Naif B.

    2013-05-01

    This thesis introduces a new chaos-based Advanced Encryption Standard (AES). The AES is a well-known encryption algorithm that was standardized by U.S National Institute of Standard and Technology (NIST) in 2001. The thesis investigates and explores the behavior of the AES algorithm by replacing two of its original modules, namely the S-Box and the Key Schedule, with two other chaos- based modules. Three chaos systems are considered in designing the new modules which are Lorenz system with multiplication nonlinearity, Chen system with sign modules nonlinearity, and 1D multiscroll system with stair case nonlinearity. The three systems are evaluated on their sensitivity to initial conditions and as Pseudo Random Number Generators (PRNG) after applying a post-processing technique to their output then performing NIST SP. 800-22 statistical tests. The thesis presents a hardware implementation of dynamic S-Boxes for AES that are populated using the three chaos systems. Moreover, a full MATLAB package to analyze the chaos generated S-Boxes based on graphical analysis, Walsh-Hadamard spectrum analysis, and image encryption analysis is developed. Although these S-Boxes are dynamic, meaning they are regenerated whenever the encryption key is changed, the analysis results show that such S-Boxes exhibit good properties like the Strict Avalanche Criterion (SAC) and the nonlinearity and in the application of image encryption. Furthermore, the thesis presents a new Lorenz-chaos-based key expansion for the AES. Many researchers have pointed out that there are some defects in the original key expansion of AES and thus have motivated such chaos-based key expansion proposal. The new proposed key schedule is analyzed and assessed in terms of confusion and diffusion by performing the frequency and SAC test respectively. The obtained results show that the new proposed design is more secure than the original AES key schedule and other proposed designs in the literature. The proposed

  13. Phase and amplitude modification of a laser beam by two deformable mirrors using conventional 4f image encryption techniques

    Science.gov (United States)

    Wu, Chensheng; Ko, Jonathan; Rzasa, John Robertson; Davis, Christopher C.

    2017-08-01

    The image encryption and decryption technique using lens components and random phase screens has attracted a great deal of research interest in the past few years. In general, the optical encryption technique can translate a positive image into an image with nearly a white speckle pattern that is impossible to decrypt. However, with the right keys as conjugated random phase screens, the white noise speckle pattern can be decoded into the original image. We find that the fundamental ideas in image encryption can be borrowed and applied to carry out beam corrections through turbulent channels. Based on our detailed analysis, we show that by using two deformable mirrors arranged in similar fashions as in the image encryption technique, a large number of controllable phase and amplitude distribution patterns can be generated from a collimated Gaussian beam. Such a result can be further coupled with wavefront sensing techniques to achieve laser beam correction against turbulence distortions. In application, our approach leads to a new type of phase conjugation mirror that could be beneficial for directed energy systems.

  14. An Optical Encryption and Decryption Method and System

    DEFF Research Database (Denmark)

    2000-01-01

    The invention relates to securing of information utilising optical imaging technologies and more specifically to phase encryption and decryption of images. An image is encrypted into a mask having a plurality of mask resolution elements (Xm, Ym) by encoding the image using e.g. a phase mask...

  15. Chaos-Based Simultaneous Compression and Encryption for Hadoop.

    Science.gov (United States)

    Usama, Muhammad; Zakaria, Nordin

    2017-01-01

    Data compression and encryption are key components of commonly deployed platforms such as Hadoop. Numerous data compression and encryption tools are presently available on such platforms and the tools are characteristically applied in sequence, i.e., compression followed by encryption or encryption followed by compression. This paper focuses on the open-source Hadoop framework and proposes a data storage method that efficiently couples data compression with encryption. A simultaneous compression and encryption scheme is introduced that addresses an important implementation issue of source coding based on Tent Map and Piece-wise Linear Chaotic Map (PWLM), which is the infinite precision of real numbers that result from their long products. The approach proposed here solves the implementation issue by removing fractional components that are generated by the long products of real numbers. Moreover, it incorporates a stealth key that performs a cyclic shift in PWLM without compromising compression capabilities. In addition, the proposed approach implements a masking pseudorandom keystream that enhances encryption quality. The proposed algorithm demonstrated a congruent fit within the Hadoop framework, providing robust encryption security and compression.

  16. A novel chaotic encryption scheme based on arithmetic coding

    International Nuclear Information System (INIS)

    Mi Bo; Liao Xiaofeng; Chen Yong

    2008-01-01

    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

  17. Performance Analysis of Chaotic Encryption Using a Shared Image ...

    African Journals Online (AJOL)

    Most of the secret key encryption algorithms in use today are designed based on either the feistel structure or the substitution-permutation structure. This paper focuses on data encryption technique using multi-scroll chaotic natures and a publicly shared image as a key. A key is generated from the shared image using a full ...

  18. Using secret sharing for searching in encrypted data

    NARCIS (Netherlands)

    Brinkman, Richard; Doumen, J.M.; Jonker, Willem; Jonker, W.; Petkovic, M.

    2004-01-01

    When outsourcing data to an untrusted database server, the data should be encrypted. When using thin clients or low-bandwidth networks it is best to perform most of the work at the server. We present a method, inspired by secure multi-party computation, to search efficiently in encrypted data. XML

  19. General Impossibility of Group Homomorphic Encryption in the Quantum World

    NARCIS (Netherlands)

    Armknecht, Frederik; Gagliardoni, Tommaso; Katzenbeisser, Stefan; Peter, Andreas

    2014-01-01

    Group homomorphic encryption represents one of the most important building blocks in modern cryptography. It forms the basis of widely-used, more sophisticated primitives, such as CCA2-secure encryption or secure multiparty computation. Unfortunately, recent advances in quantum computation show that

  20. Efficient reversible data hiding in encrypted H.264/AVC videos

    Science.gov (United States)

    Xu, Dawen; Wang, Rangding

    2014-09-01

    Due to the security and privacy-preserving requirements for cloud data management, it is sometimes desired that video content is accessible in an encrypted form. Reversible data hiding in the encrypted domain is an emerging technology, as it can perform data hiding in encrypted videos without decryption, which preserves the confidentiality of the content. Furthermore, the original cover can be losslessly restored after decryption and data extraction. An efficient reversible data hiding scheme for encrypted H.264/AVC videos is proposed. During H.264/AVC encoding, the intraprediction mode, motion vector difference, and the sign bits of the residue coefficients are encrypted using a standard stream cipher. Then, the data-hider who does not know the original video content, may reversibly embed secret data into the encrypted H.264/AVC video by using a modified version of the histogram shifting technique. A scale factor is utilized for selecting the embedding zone, which is scalable for different capacity requirements. With an encrypted video containing hidden data, data extraction can be carried out either in the encrypted or decrypted domain. In addition, real reversibility is realized so that data extraction and video recovery are free of any error. Experimental results demonstrate the feasibility and efficiency of the proposed scheme.

  1. Three-dimensional information encryption and anticounterfeiting using digital holography.

    Science.gov (United States)

    Shiu, Min-Tzung; Chew, Yang-Kun; Chan, Huang-Tian; Wong, Xin-Yu; Chang, Chi-Ching

    2015-01-01

    In this work, arbitrary micro phase-step digital holography with optical interferometry and digital image processing is utilized to obtain information about an image of a three-dimensional object and encrypting keys. Then, a computer-generated hologram is used for the purpose of holographic encryption. All information about the keys is required to perform the decryption, comprising the amplitude and phase distribution of the encrypting key, the distance of image reconstruction, zero-order term elimination, and twin-image term suppression. In addition to using identifiable information on different image planes and linear superposition processing hidden within the encrypted information, not only can we convey an important message, but we can also achieve anticounterfeiting. This approach retains the strictness of traditional holographic encryption and the convenience of digital holographic processing without image distortion. Therefore, this method provides better solutions to earlier methods for the security of the transmission of holographic information.

  2. A Contents Encryption Mechanism Using Reused Key in IPTV

    Science.gov (United States)

    Jeong, Yoon-Su; Kim, Yong-Tae; Cho, Young-Bok; Lee, Ki-Jeong; Park, Gil-Cheol; Lee, Sang-Ho

    Recently IPTV is being spotlighted as a new stream service to stably provide video, audio and control signals to subscribers through the application of IP protocol. However, the IPTV system is facing more security threats than the traditional TV. This study proposes a multicasting encryption mechanism for secure transmission of the contents of IPTV by which the content provider encrypts their contents and send the encrypted contents and the key used for encryption of the contents to the user. In order to reduce the time and cost of Head-End, the proposed mechanism encrypts the media contents at the Head-End, embeds the code of the IPTV terminal used at the Head-End in the media contents for user tracking, and performs desynchronization for protection of the media contents from various attacks.

  3. Key-space analysis of double random phase encryption technique

    Science.gov (United States)

    Monaghan, David S.; Gopinathan, Unnikrishnan; Naughton, Thomas J.; Sheridan, John T.

    2007-09-01

    We perform a numerical analysis on the double random phase encryption/decryption technique. The key-space of an encryption technique is the set of possible keys that can be used to encode data using that technique. In the case of a strong encryption scheme, many keys must be tried in any brute-force attack on that technique. Traditionally, designers of optical image encryption systems demonstrate only how a small number of arbitrary keys cannot decrypt a chosen encrypted image in their system. However, this type of demonstration does not discuss the properties of the key-space nor refute the feasibility of an efficient brute-force attack. To clarify these issues we present a key-space analysis of the technique. For a range of problem instances we plot the distribution of decryption errors in the key-space indicating the lack of feasibility of a simple brute-force attack.

  4. Discrete-Time Biomedical Signal Encryption

    Directory of Open Access Journals (Sweden)

    Victor Grigoraş

    2017-12-01

    Full Text Available Chaotic modulation is a strong method of improving communication security. Analog and discrete chaotic systems are presented in actual literature. Due to the expansion of digital communication, discrete-time systems become more efficient and closer to actual technology. The present contribution offers an in-depth analysis of the effects chaos encryption produce on 1D and 2D biomedical signals. The performed simulations show that modulating signals are precisely recovered by the synchronizing receiver if discrete systems are digitally implemented and the coefficients precisely correspond. Channel noise is also applied and its effects on biomedical signal demodulation are highlighted.

  5. A New Measurement Method of Iimage Encryption

    International Nuclear Information System (INIS)

    Yu, X Y; Zhang, J; Ren, H E; Li, S; Zhang, X D

    2006-01-01

    Image scrambling transformation is applied widely in the digital watermarking and image encryption. Although more and more scrambling algorithms appear, they lack a method to evaluate the image scrambling degree. According to the relative differences of a point and adjacent point in scrambling front and back, a new method which judges the scrambling degree is proposed. Not only it can evaluate the change of each pixel's position, but also evaluate the change of adjacent pixel's value. Apply Matlab to the simulation experiment, the result indicated that this method can evaluate image scrambling degree well, and it accorded with people's vision too

  6. Genetic differentiation in natural populations of Lutzomyia longipalpis (Lutz & Neiva) (Diptera: Psychodidae) with different phenotypic spot patterns on tergites in males.

    Science.gov (United States)

    Silva, M H; Nascimento, M D S B; Leonardo, F S; Rebêlo, J M M; Pereira, S R F

    2011-01-01

    Entomological surveys in the state of Maranhão have recorded morphologically distinct populations of Lutzomyia longipalpis (Lutz & Neiva). Some populations have one pair of spots (1S) on the fourth tergite, while others have two pairs (2S) on the third and fourth tergites of males. In the present study we investigated the degree of genetic polymorphism among four populations in the municipalities of Caxias, Codó and Raposa, in the state of Maranhão, Brazil, by using RAPD (Random Amplified Polymorphic DNA) markers. A total of 35 loci were identified, of which 30 were polymorphic. The highest polymorphism was observed with primer OPA 4, which produced 11 different profiles. Genetic diversity was assessed using grouping methods that produced a dendrogram in which the genotypes could be clearly separated into two main clades according to the number of spots on the male abdominal tergites. One cluster contained the populations from Caxias and Codó, and the other was formed by the populations from Raposa and Codó. The results of our RAPD analysis showed a clear separation between the populations with one and two pairs of spots. The epidemiologic significance of this genetic differentiation should be investigated in future studies.

  7. Wireless Networks Speed Depending on the Encryption using Windows 8.1 x64 Operating System

    Directory of Open Access Journals (Sweden)

    Tamás Krausz

    2014-12-01

    Full Text Available We can use variety of encryption standards to encrypt data traffic to ensure the safety of wireless networks. The question is to what extent the security of the network affects network performance. For answering this question, experiments were performed without data encryption, and the use of various encryption standards.

  8. A Type-and-Identity-based Proxy Re-Encryption Scheme and its Application in Healthcare

    NARCIS (Netherlands)

    Ibraimi, L.; Tang, Qiang; Hartel, Pieter H.; Jonker, Willem

    2008-01-01

    Proxy re-encryption is a cryptographic primitive developed to delegate the decryption right from one party (the delegator) to another (the delegatee). In a proxy re-encryption scheme, the delegator assigns a key to a proxy to re-encrypt all messages encrypted with his public key such that the

  9. SpotADAPT

    DEFF Research Database (Denmark)

    Kaulakiene, Dalia; Thomsen, Christian; Pedersen, Torben Bach

    2015-01-01

    by Amazon Web Services (AWS). The users aiming for the spot market are presented with many instance types placed in multiple datacenters in the world, and thus it is difficult to choose the optimal deployment. In this paper, we propose the framework SpotADAPT (Spot-Aware (re-)Deployment of Analytical...... execution within boundaries). Moreover, during the execution of the workload, SpotADAPT suggests a redeployment if the current spot instance gets terminated by Amazon or a better deployment becomes possible due to fluctuations of the spot prices. The approach is evaluated using the actual execution times...

  10. 3-D Image Encryption Based on Rubik's Cube and RC6 Algorithm

    Science.gov (United States)

    Helmy, Mai; El-Rabaie, El-Sayed M.; Eldokany, Ibrahim M.; El-Samie, Fathi E. Abd

    2017-12-01

    A novel encryption algorithm based on the 3-D Rubik's cube is proposed in this paper to achieve 3D encryption of a group of images. This proposed encryption algorithm begins with RC6 as a first step for encrypting multiple images, separately. After that, the obtained encrypted images are further encrypted with the 3-D Rubik's cube. The RC6 encrypted images are used as the faces of the Rubik's cube. From the concepts of image encryption, the RC6 algorithm adds a degree of diffusion, while the Rubik's cube algorithm adds a degree of permutation. The simulation results demonstrate that the proposed encryption algorithm is efficient, and it exhibits strong robustness and security. The encrypted images are further transmitted over wireless Orthogonal Frequency Division Multiplexing (OFDM) system and decrypted at the receiver side. Evaluation of the quality of the decrypted images at the receiver side reveals good results.

  11. PDES, Fips Standard Data Encryption Algorithm

    International Nuclear Information System (INIS)

    Nessett, D.N.

    1991-01-01

    Description of program or function: PDES performs the National Bureau of Standards FIPS Pub. 46 data encryption/decryption algorithm used for the cryptographic protection of computer data. The DES algorithm is designed to encipher and decipher blocks of data consisting of 64 bits under control of a 64-bit key. The key is generated in such a way that each of the 56 bits used directly by the algorithm are random and the remaining 8 error-detecting bits are set to make the parity of each 8-bit byte of the key odd, i. e. there is an odd number of '1' bits in each 8-bit byte. Each member of a group of authorized users of encrypted computer data must have the key that was used to encipher the data in order to use it. Data can be recovered from cipher only by using exactly the same key used to encipher it, but with the schedule of addressing the key bits altered so that the deciphering process is the reverse of the enciphering process. A block of data to be enciphered is subjected to an initial permutation, then to a complex key-dependent computation, and finally to a permutation which is the inverse of the initial permutation. Two PDES routines are included; both perform the same calculation. One, identified as FDES.MAR, is designed to achieve speed in execution, while the other identified as PDES.MAR, presents a clearer view of how the algorithm is executed

  12. Comb to Pipeline: Fast Software Encryption Revisited

    DEFF Research Database (Denmark)

    Bogdanov, Andrey; Lauridsen, Martin Mehl; Tischhauser, Elmar Wolfgang

    2015-01-01

    AES-NI, or Advanced Encryption Standard New Instructions, is an extension of the x86 architecture proposed by Intel in 2008. With a pipelined implementation utilizing AES-NI, parallelizable modes such as AES-CTR become extremely efficient. However, out of the four non-trivial NIST-recommended enc......AES-NI, or Advanced Encryption Standard New Instructions, is an extension of the x86 architecture proposed by Intel in 2008. With a pipelined implementation utilizing AES-NI, parallelizable modes such as AES-CTR become extremely efficient. However, out of the four non-trivial NIST...... look-ahead strategy, featuring a low overhead – with which sequential modes profit from the AES-NI pipeline in real-world settings by filling it with multiple, independent messages. We apply the comb scheduler to implementations on Haswell, Intel’s latest microarchitecture, for a wide range of modes...... significantly speeds up CLOC/SILC, JAMBU, and POET, with the mostly sequential nonce-misuse resistant design of POET, performing at 2.14 cpb, becoming faster than the well-parallelizable COPA. Finally, this paper provides the first optimized AES-NI implementations for the novel AE modes OTR, CLOC/SILC, COBRA...

  13. New modified map for digital image encryption and its performance

    Science.gov (United States)

    Suryadi, MT; Yus Trinity Irsan, Maria; Satria, Yudi

    2017-10-01

    Protection to classified digital data becomes so important in avoiding data manipulation and alteration. The focus of this paper is in data and information protection of digital images form. Protection is provided in the form of encrypted digital image. The encryption process uses a new map, {x}n+1=\\frac{rλ {x}n}{1+λ {(1-{x}n)}2}\\quad ({mod} 1), which is called MS map. This paper will show: the results of digital image encryption using MS map and how the performance is regarding the average time needed for encryption/decryption process; randomness of key stream sequence with NIST test, histogram analysis and goodness of fit test, quality of the decrypted image by PSNR, initial value sensitivity level, and key space. The results show that the average time of the encryption process is relatively same as the decryption process and it depends to types and sizes of the image. Cipherimage (encrypted image) is uniformly distributed since: it passes the goodness of fit test and also the histogram of the cipherimage is flat; key stream, that are generated by MS map, passes frequency (monobit) test, and runs test, which means the key stream is a random sequence; the decrypted image has same quality as the original image; and initial value sensitivity reaches 10-17, and key space reaches 3.24 × 10634. So, that encryption algorithm generated by MS map is more resistant to brute-force attack and known plaintext attack.

  14. A Review Of Encryption Algorithms-RSA And Diffie-Hellman

    Directory of Open Access Journals (Sweden)

    Nilesh A. Lal

    2017-07-01

    Full Text Available Network security is protecting data and message from cybercrime. Cryptography system is designed freely to communicate over a computer network. It is a process where sender sends encrypted message to the recipient. Symmetric encryption is known as the single key encryption. RSA algorithm is a symmetric key encryption.it uses public key and private key. Diffie Hellman cryptography is where both parties exchange secrets keys to encrypt message.

  15. Simple Multi-Authority Attribute-Based Encryption for Short Messages

    OpenAIRE

    Viktoria I. Villanyi

    2016-01-01

    Central authority free multi-authority attribute based encryption scheme for short messages will be presented. Several multi-authority attribute based encryption schemes were recently proposed. We can divide these schemes into two groups, one of them are the ciphertext-policy attribute based encryption schemes (CP-ABE), the another one are the key-policy attribute based encryption schemes (KP-ABE). In our new multi-authority attribute based encryption scheme we combine them: the access struct...

  16. A Novel Image Encryption Algorithm Based on DNA Subsequence Operation

    Directory of Open Access Journals (Sweden)

    Qiang Zhang

    2012-01-01

    Full Text Available We present a novel image encryption algorithm based on DNA subsequence operation. Different from the traditional DNA encryption methods, our algorithm does not use complex biological operation but just uses the idea of DNA subsequence operations (such as elongation operation, truncation operation, deletion operation, etc. combining with the logistic chaotic map to scramble the location and the value of pixel points from the image. The experimental results and security analysis show that the proposed algorithm is easy to be implemented, can get good encryption effect, has a wide secret key's space, strong sensitivity to secret key, and has the abilities of resisting exhaustive attack and statistic attack.

  17. System for processing an encrypted instruction stream in hardware

    Science.gov (United States)

    Griswold, Richard L.; Nickless, William K.; Conrad, Ryan C.

    2016-04-12

    A system and method of processing an encrypted instruction stream in hardware is disclosed. Main memory stores the encrypted instruction stream and unencrypted data. A central processing unit (CPU) is operatively coupled to the main memory. A decryptor is operatively coupled to the main memory and located within the CPU. The decryptor decrypts the encrypted instruction stream upon receipt of an instruction fetch signal from a CPU core. Unencrypted data is passed through to the CPU core without decryption upon receipt of a data fetch signal.

  18. A joint asymmetric watermarking and image encryption scheme

    Science.gov (United States)

    Boato, G.; Conotter, V.; De Natale, F. G. B.; Fontanari, C.

    2008-02-01

    Here we introduce a novel watermarking paradigm designed to be both asymmetric, i.e., involving a private key for embedding and a public key for detection, and commutative with a suitable encryption scheme, allowing both to cipher watermarked data and to mark encrypted data without interphering with the detection process. In order to demonstrate the effectiveness of the above principles, we present an explicit example where the watermarking part, based on elementary linear algebra, and the encryption part, exploiting a secret random permutation, are integrated in a commutative scheme.

  19. Hardware Realization of Chaos Based Symmetric Image Encryption

    KAUST Repository

    Barakat, Mohamed L.

    2012-06-01

    This thesis presents a novel work on hardware realization of symmetric image encryption utilizing chaos based continuous systems as pseudo random number generators. Digital implementation of chaotic systems results in serious degradations in the dynamics of the system. Such defects are illuminated through a new technique of generalized post proceeding with very low hardware cost. The thesis further discusses two encryption algorithms designed and implemented as a block cipher and a stream cipher. The security of both systems is thoroughly analyzed and the performance is compared with other reported systems showing a superior results. Both systems are realized on Xilinx Vetrix-4 FPGA with a hardware and throughput performance surpassing known encryption systems.

  20. Efficient KDM-CCA Secure Public-Key Encryption via Auxiliary-Input Authenticated Encryption

    Directory of Open Access Journals (Sweden)

    Shuai Han

    2017-01-01

    Full Text Available KDM[F]-CCA security of public-key encryption (PKE ensures the privacy of key-dependent messages f(sk which are closely related to the secret key sk, where f∈F, even if the adversary is allowed to make decryption queries. In this paper, we study the design of KDM-CCA secure PKE. To this end, we develop a new primitive named Auxiliary-Input Authenticated Encryption (AIAE. For AIAE, we introduce two related-key attack (RKA security notions, including IND-RKA and weak-INT-RKA. We present a generic construction of AIAE from tag-based hash proof system (HPS and one-time secure authenticated encryption (AE and give an instantiation of AIAE under the Decisional Diffie-Hellman (DDH assumption. Using AIAE as an essential building block, we give two constructions of efficient KDM-CCA secure PKE based on the DDH and the Decisional Composite Residuosity (DCR assumptions. Specifically, (i our first PKE construction is the first one achieving KDM[Faff]-CCA security for the set of affine functions and compactness of ciphertexts simultaneously. (ii Our second PKE construction is the first one achieving KDM[Fpolyd]-CCA security for the set of polynomial functions and almost compactness of ciphertexts simultaneously. Our PKE constructions are very efficient; in particular, they are pairing-free and NIZK-free.

  1. A Novel Method for Generating Encryption Keys

    Directory of Open Access Journals (Sweden)

    Dascalescu Ana Cristina

    2009-12-01

    Full Text Available The development of the informational society, which has led to an impressive growth of the information volume circulating in the computer networks, has accelerated the evolution and especially the use of modern cryptography instruments. Today, the commercial products use standard cryptographic libraries that implement certified and tested cryptographic algorithms. Instead, the fragility ofencryption algorithms is given by compositional operations like key handling or key generation. In this sense, the article proposes an innovative method to generate pseudorandom numbers which can be used for the construction of secure stream encryption keys. The proposed method is based on the mathematical complements based on the algebra of the finite fields and uses a particularized structure of the linear feedback shift registers.

  2. Optical encryption using pseudorandom complex spatial modulation.

    Science.gov (United States)

    Sarkadi, Tamás; Koppa, Pál

    2012-12-01

    In this paper we propose a new (to our knowledge) complex spatial modulation method to encode data pages applicable in double random phase encryption (DRPE) to make the system more resistant to brute-force attack. The proposed modulation method uses data page pixels with random phase and amplitude values with the condition that the intensity of the interference of light from two adjacent pixels should correspond to the encoded information. A differential phase contrast technique is applied to recover the data page at the output of the system. We show that the proposed modulation method can enhance the robustness of the DRPE technique using point spread function analysis. Key space expansion is determined by numeric model calculations.

  3. Dual plane multiple spatial watermarking with self-encryption

    Indian Academy of Sciences (India)

    general social networking user may require watermarking but with less computational costs and with no compulsion of manually providing and maintaining different secrete keys. This type of user can be benefitted by using self-encryption and skip-.

  4. Quantum Image Encryption Algorithm Based on Image Correlation Decomposition

    Science.gov (United States)

    Hua, Tianxiang; Chen, Jiamin; Pei, Dongju; Zhang, Wenquan; Zhou, Nanrun

    2015-02-01

    A novel quantum gray-level image encryption and decryption algorithm based on image correlation decomposition is proposed. The correlation among image pixels is established by utilizing the superposition and measurement principle of quantum states. And a whole quantum image is divided into a series of sub-images. These sub-images are stored into a complete binary tree array constructed previously and then randomly performed by one of the operations of quantum random-phase gate, quantum revolving gate and Hadamard transform. The encrypted image can be obtained by superimposing the resulting sub-images with the superposition principle of quantum states. For the encryption algorithm, the keys are the parameters of random phase gate, rotation angle, binary sequence and orthonormal basis states. The security and the computational complexity of the proposed algorithm are analyzed. The proposed encryption algorithm can resist brute force attack due to its very large key space and has lower computational complexity than its classical counterparts.

  5. Chaos-based image encryption algorithm [rapid communication

    Science.gov (United States)

    Guan, Zhi-Hong; Huang, Fangjun; Guan, Wenjie

    2005-10-01

    In this Letter, a new image encryption scheme is presented, in which shuffling the positions and changing the grey values of image pixels are combined to confuse the relationship between the cipher-image and the plain-image. Firstly, the Arnold cat map is used to shuffle the positions of the image pixels in the spatial-domain. Then the discrete output signal of the Chen's chaotic system is preprocessed to be suitable for the grayscale image encryption, and the shuffled image is encrypted by the preprocessed signal pixel by pixel. The experimental results demonstrate that the key space is large enough to resist the brute-force attack and the distribution of grey values of the encrypted image has a random-like behavior.

  6. Hardware Realization of Chaos-based Symmetric Video Encryption

    KAUST Repository

    Ibrahim, Mohamad A.

    2013-05-01

    This thesis reports original work on hardware realization of symmetric video encryption using chaos-based continuous systems as pseudo-random number generators. The thesis also presents some of the serious degradations caused by digitally implementing chaotic systems. Subsequently, some techniques to eliminate such defects, including the ultimately adopted scheme are listed and explained in detail. Moreover, the thesis describes original work on the design of an encryption system to encrypt MPEG-2 video streams. Information about the MPEG-2 standard that fits this design context is presented. Then, the security of the proposed system is exhaustively analyzed and the performance is compared with other reported systems, showing superiority in performance and security. The thesis focuses more on the hardware and the circuit aspect of the system’s design. The system is realized on Xilinx Vetrix-4 FPGA with hardware parameters and throughput performance surpassing conventional encryption systems.

  7. Optical design of cipher block chaining (CBC) encryption mode by using digital holography

    Science.gov (United States)

    Gil, Sang Keun; Jeon, Seok Hee; Jung, Jong Rae; Kim, Nam

    2016-03-01

    We propose an optical design of cipher block chaining (CBC) encryption by using digital holographic technique, which has higher security than the conventional electronic method because of the analog-type randomized cipher text with 2-D array. In this paper, an optical design of CBC encryption mode is implemented by 2-step quadrature phase-shifting digital holographic encryption technique using orthogonal polarization. A block of plain text is encrypted with the encryption key by applying 2-step phase-shifting digital holography, and it is changed into cipher text blocks which are digital holograms. These ciphered digital holograms with the encrypted information are Fourier transform holograms and are recorded on CCDs with 256 gray levels quantized intensities. The decryption is computed by these encrypted digital holograms of cipher texts, the same encryption key and the previous cipher text. Results of computer simulations are presented to verify that the proposed method shows the feasibility in the high secure CBC encryption system.

  8. A Leakage-Abuse Attack Against Multi-User Searchable Encryption

    Directory of Open Access Journals (Sweden)

    Van Rompay Cédric

    2017-07-01

    Full Text Available Searchable Encryption (SE allows a user to upload data to the cloud and to search it in a remote fashion while preserving the privacy of both the data and the queries. Recent research results describe attacks on SE schemes using the access pattern, denoting the ids of documents matching search queries, which most SE schemes reveal during query processing. However SE schemes usually leak more than just the access pattern, and this extra leakage can lead to attacks (much more harmful than the ones using basic access pattern leakage only. We remark that in the special case of Multi-User Searchable Encryption (MUSE, where many users upload and search data in a cloud-based infrastructure, a large number of existing solutions have a common leakage in addition to the well-studied access pattern leakage. We show that this seemingly small extra leakage allows a very simple yet powerful attack, and that the privacy degree of the affected schemes have been overestimated. We also show that this new vulnerability affects existing software. Finally we formalize the newly identified leakage profile and show how it relates to previously defined ones.

  9. Batch Attribute-Based Encryption for Secure Clouds

    Directory of Open Access Journals (Sweden)

    Chen Yang

    2015-10-01

    Full Text Available Cloud storage is widely used by organizations due to its advantage of allowing universal access with low cost. Attribute-based encryption (ABE is a kind of public key encryption suitable for cloud storage. The secret key of each user and the ciphertext are associated with an access policy and an attribute set, respectively; in addition to holding a secret key, one can decrypt a ciphertext only if the associated attributes match the predetermined access policy, which allows one to enforce fine-grained access control on outsourced files. One issue in existing ABE schemes is that they are designed for the users of a single organization. When one wants to share the data with the users of different organizations, the owner needs to encrypt the messages to the receivers of one organization and then repeats this process for another organization. This situation is deteriorated with more and more mobile devices using cloud services, as the ABE encryption process is time consuming and may exhaust the power supplies of the mobile devices quickly. In this paper, we propose a batch attribute-based encryption (BABE approach to address this problem in a provably-secure way. With our approach, the data owner can outsource data in batches to the users of different organizations simultaneously. The data owner is allowed to decide the receiving organizations and the attributes required for decryption. Theoretical and experimental analyses show that our approach is more efficient than traditional encryption implementations in computation and communication.

  10. Experimental multiplexing protocol to encrypt messages of any length

    Science.gov (United States)

    Fredy Barrera, John; Vélez, Alejandro; Torroba, Roberto

    2013-05-01

    As optical systems are diffraction limited, it is not possible to encrypt in a single step texts containing a large amount of characters. We overcome this situation by separately encrypting several characters, along with a multiplexing procedure to obtain an encrypted keyboard. The experimental application is performed in a joint transform correlator architecture and using digital holography. We combine the different characters into a keyboard encrypted with a single phase mask together with a selection-position key that gives the right sequence to recover safe encrypted messages. The multiplexing operation we suggest is advantageous in the sense that the technique enables processing of messages that otherwise the optical system could not process in a single step. We also employ a repositioning technique to prevent both the natural background noise over recovered characters and the possible cross talk. The lack of any single key avoids the correct message recovery. Experimental results are presented to show the feasibility of our proposal, representing an actual application of the optical encrypting protocols.

  11. Design and implementation of encrypted and decrypted file system based on USBKey and hardware code

    Science.gov (United States)

    Wu, Kehe; Zhang, Yakun; Cui, Wenchao; Jiang, Ting

    2017-05-01

    To protect the privacy of sensitive data, an encrypted and decrypted file system based on USBKey and hardware code is designed and implemented in this paper. This system uses USBKey and hardware code to authenticate a user. We use random key to encrypt file with symmetric encryption algorithm and USBKey to encrypt random key with asymmetric encryption algorithm. At the same time, we use the MD5 algorithm to calculate the hash of file to verify its integrity. Experiment results show that large files can be encrypted and decrypted in a very short time. The system has high efficiency and ensures the security of documents.

  12. Universal Intelligent Data Encryption Standards: A Review

    Directory of Open Access Journals (Sweden)

    Renjith V Ravi

    2014-06-01

    Full Text Available -The most challenging aspects in the word of electronic communication is nothing but the data security. The significance of the exchanged data over the internet and other media types are increasing. One of the most interesting subjects in the security related communities is the hunt for the best solution to offer an essential protection against the data intruders’ attacks together with providing these services in time. Cryptography is the one of the main category of data security which converts information from its original form into an unreadable form. There are two main uniqueness to distinguish an encryption system from another are its ability to secure the protected data against cryptanalytic attacks and its speed and efficiency in the process.Cryptographic research has a common objective to design protocols that offer a confidential and authenticated transmission channel for messages over an insecure network. If a cryptographic algorithm is said to be computationally secured, it cannot be broken with typical resources, either present or future and apart from the algorithm, key distribution is also more important to make an proficient cryptographic system.

  13. Session Initiation Protocol Network Encryption Device Plain Text Domain Discovery Service

    National Research Council Canada - National Science Library

    Robson, Christopher L

    2007-01-01

    ... cryptographic devices implementing this technology, to find and exchange plain text domain (PTD) information. Additionally, SIP-DS will allow one encryption device to proxy PTD information for other encryption devices unable to implement this method.

  14. Objective measurement of intraocular forward light scatter using Hartmann-Shack spot patterns from clinical aberrometers. Model-eye and human-eye study.

    Science.gov (United States)

    Cerviño, Alejandro; Bansal, Dheeraj; Hosking, Sarah L; Montés-Micó, Robert

    2008-07-01

    To apply software-based image-analysis tools to objectively determine intraocular scatter determined from clinically derived Hartmann-Shack patterns. Aston Academy of Life Sciences, Aston University, Birmingham, United Kingdom, and Department of Optics, University of Valencia, Valencia, Spain. Purpose-designed image-analysis software was used to quantify scatter from centroid patterns obtained using a clinical Hartmann-Shack analyzer (WASCA, Zeiss/Meditec). Three scatter values, as the maximum standard deviation within a lenslet for all lenslets in the pattern, were obtained in 6 model eyes and 10 human eyes. In the model-eye sample, patterns were obtained in 4 sessions: 2 without realigning between measurements, 1 with realignment, and 1 with an angular shift of 6 degrees from the instrument axis. Three measurements were made in the human eyes with the C-Quant straylight meter (Oculus) to obtain psychometric and objective measures of retinal straylight. Analysis of variance, intraclass correlation coefficients, coefficient of repeatability (CoR), and correlations were used to determine intrasession and intersession repeatability and the relationship between measures. No significant differences were found between the sessions in the model eye (P=.234). The mean CoR was less than 10% in all model- and human-eye sessions. After incomplete patterns were removed, good correlation was achieved between psychometric and objective scatter measurements despite the small sample size (n=6; r=-0.831; P=.040). The methodology was repeatable in model and human eyes, strong against realignment and misalignment, and sensitive. Clinical application would benefit from effective use of the sensor's dynamic range.

  15. Photonic encryption : modeling and functional analysis of all optical logic.

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Jason D.; Schroeppel, Richard Crabtree; Robertson, Perry J.

    2004-10-01

    With the build-out of large transport networks utilizing optical technologies, more and more capacity is being made available. Innovations in Dense Wave Division Multiplexing (DWDM) and the elimination of optical-electrical-optical conversions have brought on advances in communication speeds as we move into 10 Gigabit Ethernet and above. Of course, there is a need to encrypt data on these optical links as the data traverses public and private network backbones. Unfortunately, as the communications infrastructure becomes increasingly optical, advances in encryption (done electronically) have failed to keep up. This project examines the use of optical logic for implementing encryption in the photonic domain to achieve the requisite encryption rates. This paper documents the innovations and advances of work first detailed in 'Photonic Encryption using All Optical Logic,' [1]. A discussion of underlying concepts can be found in SAND2003-4474. In order to realize photonic encryption designs, technology developed for electrical logic circuits must be translated to the photonic regime. This paper examines S-SEED devices and how discrete logic elements can be interconnected and cascaded to form an optical circuit. Because there is no known software that can model these devices at a circuit level, the functionality of S-SEED devices in an optical circuit was modeled in PSpice. PSpice allows modeling of the macro characteristics of the devices in context of a logic element as opposed to device level computational modeling. By representing light intensity as voltage, 'black box' models are generated that accurately represent the intensity response and logic levels in both technologies. By modeling the behavior at the systems level, one can incorporate systems design tools and a simulation environment to aid in the overall functional design. Each black box model takes certain parameters (reflectance, intensity, input response), and models the optical ripple

  16. Comparable Encryption Scheme over Encrypted Cloud Data in Internet of Everything

    Directory of Open Access Journals (Sweden)

    Qian Meng

    2017-01-01

    Full Text Available User authentication has been widely deployed to prevent unauthorized access in the new era of Internet of Everything (IOE. When user passes the legal authentication, he/she can do series of operations in database. We mainly concern issues of data security and comparable queries over ciphertexts in IOE. In traditional database, a Short Comparable Encryption (SCE scheme has been widely used by authorized users to conduct comparable queries over ciphertexts, but existing SCE schemes still incur high storage and computational overhead as well as economic burden. In this paper, we first propose a basic Short Comparable Encryption scheme based on sliding window method (SCESW, which can significantly reduce computational and storage burden as well as enhance work efficiency. Unfortunately, as the cloud service provider is a semitrusted third party, public auditing mechanism needs to be furnished to protect data integrity. To further protect data integrity and reduce management overhead, we present an enhanced SCESW scheme based on position-aware Merkle tree, namely, PT-SCESW. Security analysis proves that PT-SCESW and SCESW schemes can guarantee completeness and weak indistinguishability in standard model. Performance evaluation indicates that PT-SCESW scheme is efficient and feasible in practical applications, especially for smarter and smaller computing devices in IOE.

  17. Spot market for uranium

    International Nuclear Information System (INIS)

    Colhoun, C.

    1982-01-01

    The spot market is always quoted for the price of uranium because little information is available about long-term contracts. A review of the development of spot market prices shows the same price curve swings that occur with all raw materials. Future long-term contracts will probably be lower to reflect spot market prices, which are currently in the real-value range of $30-$35. An upswing in the price of uranium could come in the next few months as utilities begin making purchases and trading from stockpiles. The US, unlike Europe and Japan, has already reached a supply and demand point where the spot market share is increasing. Forecasters cannot project the market price, they can only predict the presence of an oscillating spot or a secondary market. 5 figures

  18. Security encryption for video-on-radio devices

    Science.gov (United States)

    Perrone, Antonio L.; Basti, Gianfranco

    2002-03-01

    In this paper we present an encryption module included in the Subsidiary Communication Channel (SCC) System we are developing for video-on-FM radio broadcasting. This module is aimed to encrypt by symmetric key the video image archive and real-time database of the broadcaster, and by asymmetric key the video broadcasting to final users. The module includes our proprietary Techniteia Encryption Library (TEL), that is already successfully running and securing several e-commerce portals in Europe. TEL is written in C-ANSI language for its easy exportation onto all main platforms and it is optimized for real-time applications. It is based on the blowfish encryption algorithm and it is characterized by a physically separated sub-module for the automatic generation/recovering of the variable sub-keys of the blowfish algorithm. In this way, different parts of the database are encrypted by different keys, both in space and in time, for granting an optimal security.

  19. Searchable Data Vault: Encrypted Queries in Secure Distributed Cloud Storage

    Directory of Open Access Journals (Sweden)

    Geong Sen Poh

    2017-05-01

    Full Text Available Cloud storage services allow users to efficiently outsource their documents anytime and anywhere. Such convenience, however, leads to privacy concerns. While storage providers may not read users’ documents, attackers may possibly gain access by exploiting vulnerabilities in the storage system. Documents may also be leaked by curious administrators. A simple solution is for the user to encrypt all documents before submitting them. This method, however, makes it impossible to efficiently search for documents as they are all encrypted. To resolve this problem, we propose a multi-server searchable symmetric encryption (SSE scheme and construct a system called the searchable data vault (SDV. A unique feature of the scheme is that it allows an encrypted document to be divided into blocks and distributed to different storage servers so that no single storage provider has a complete document. By incorporating the scheme, the SDV protects the privacy of documents while allowing for efficient private queries. It utilizes a web interface and a controller that manages user credentials, query indexes and submission of encrypted documents to cloud storage services. It is also the first system that enables a user to simultaneously outsource and privately query documents from a few cloud storage services. Our preliminary performance evaluation shows that this feature introduces acceptable computation overheads when compared to submitting documents directly to a cloud storage service.

  20. Color image encryption based on gyrator transform and Arnold transform

    Science.gov (United States)

    Sui, Liansheng; Gao, Bo

    2013-06-01

    A color image encryption scheme using gyrator transform and Arnold transform is proposed, which has two security levels. In the first level, the color image is separated into three components: red, green and blue, which are normalized and scrambled using the Arnold transform. The green component is combined with the first random phase mask and transformed to an interim using the gyrator transform. The first random phase mask is generated with the sum of the blue component and a logistic map. Similarly, the red component is combined with the second random phase mask and transformed to three-channel-related data. The second random phase mask is generated with the sum of the phase of the interim and an asymmetrical tent map. In the second level, the three-channel-related data are scrambled again and combined with the third random phase mask generated with the sum of the previous chaotic maps, and then encrypted into a gray scale ciphertext. The encryption result has stationary white noise distribution and camouflage property to some extent. In the process of encryption and decryption, the rotation angle of gyrator transform, the iterative numbers of Arnold transform, the parameters of the chaotic map and generated accompanied phase function serve as encryption keys, and hence enhance the security of the system. Simulation results and security analysis are presented to confirm the security, validity and feasibility of the proposed scheme.

  1. Fast encryption of image data using chaotic Kolmogorov flows

    Science.gov (United States)

    Scharinger, Josef

    1998-04-01

    To guarantee security and privacy in image and video archival applications, efficient bulk encryption techniques are necessary which are easily implementable in soft- and hardware and are able to cope with the vast amounts of data involved. Experience has shown that block-oriented symmetric product ciphers constitute an adequate design paradigm for resolving this task, since they can offer a very high level of security as well as very high encryption rates. In this contribution we introduce a new product cipher which encrypts large blocks of plain text by repeated intertwined application of substitution and permutation operations. While almost all of the current product ciphers use fixed permutation operations on small data blocks, our approach involves parametrizable permutations on large data blocks induced by specific chaotic systems. By combining these highly unstable dynamics with an adaption of a very fast shift register based pseudo-random number generator, we obtain a new class of computationally secure product ciphers which offer many features that make them superior to contemporary bulk encryption systems when aiming at efficient image and video data encryption.

  2. The Design of Simple Bacterial Microarrays: Development towards Immobilizing Single Living Bacteria on Predefined Micro-Sized Spots on Patterned Surfaces.

    Directory of Open Access Journals (Sweden)

    Nina Bjørk Arnfinnsdottir

    Full Text Available In this paper we demonstrate a procedure for preparing bacterial arrays that is fast, easy, and applicable in a standard molecular biology laboratory. Microcontact printing is used to deposit chemicals promoting bacterial adherence in predefined positions on glass surfaces coated with polymers known for their resistance to bacterial adhesion. Highly ordered arrays of immobilized bacteria were obtained using microcontact printed islands of polydopamine (PD on glass surfaces coated with the antiadhesive polymer polyethylene glycol (PEG. On such PEG-coated glass surfaces, bacteria were attached to 97 to 100% of the PD islands, 21 to 62% of which were occupied by a single bacterium. A viability test revealed that 99% of the bacteria were alive following immobilization onto patterned surfaces. Time series imaging of bacteria on such arrays revealed that the attached bacteria both divided and expressed green fluorescent protein, both of which indicates that this method of patterning of bacteria is a suitable method for single-cell analysis.

  3. Efficient Conditional Proxy Re-encryption with Chosen-Ciphertext Security

    NARCIS (Netherlands)

    Weng, Jiang; Yang, Yanjiang; Tang, Qiang; Deng, Robert H.; Bao, Feng

    Recently, a variant of proxy re-encryption, named conditional proxy re-encryption (C-PRE), has been introduced. Compared with traditional proxy re-encryption, C-PRE enables the delegator to implement fine-grained delegation of decryption rights, and thus is more useful in many applications. In this

  4. An Advanced Encryption Standard Powered Mutual Authentication Protocol Based on Elliptic Curve Cryptography for RFID, Proven on WISP

    Directory of Open Access Journals (Sweden)

    Alaauldin Ibrahim

    2017-01-01

    Full Text Available Information in patients’ medical histories is subject to various security and privacy concerns. Meanwhile, any modification or error in a patient’s medical data may cause serious or even fatal harm. To protect and transfer this valuable and sensitive information in a secure manner, radio-frequency identification (RFID technology has been widely adopted in healthcare systems and is being deployed in many hospitals. In this paper, we propose a mutual authentication protocol for RFID tags based on elliptic curve cryptography and advanced encryption standard. Unlike existing authentication protocols, which only send the tag ID securely, the proposed protocol could also send the valuable data stored in the tag in an encrypted pattern. The proposed protocol is not simply a theoretical construct; it has been coded and tested on an experimental RFID tag. The proposed scheme achieves mutual authentication in just two steps and satisfies all the essential security requirements of RFID-based healthcare systems.

  5. Real-time and encryption efficiency improvements of simultaneous fusion, compression and encryption method based on chaotic generators

    Science.gov (United States)

    Jridi, Maher; Alfalou, Ayman

    2018-03-01

    In this paper, enhancement of an existing optical simultaneous fusion, compression and encryption (SFCE) scheme in terms of real-time requirements, bandwidth occupation and encryption robustness is proposed. We have used and approximate form of the DCT to decrease the computational resources. Then, a novel chaos-based encryption algorithm is introduced in order to achieve the confusion and diffusion effects. In the confusion phase, Henon map is used for row and column permutations, where the initial condition is related to the original image. Furthermore, the Skew Tent map is employed to generate another random matrix in order to carry out pixel scrambling. Finally, an adaptation of a classical diffusion process scheme is employed to strengthen security of the cryptosystem against statistical, differential, and chosen plaintext attacks. Analyses of key space, histogram, adjacent pixel correlation, sensitivity, and encryption speed of the encryption scheme are provided, and favorably compared to those of the existing crypto-compression system. The proposed method has been found to be digital/optical implementation-friendly which facilitates the integration of the crypto-compression system on a very broad range of scenarios.

  6. Study of Wireless Authentication Center with Mixed Encryption in WSN

    Directory of Open Access Journals (Sweden)

    Yiqin Lu

    2016-01-01

    Full Text Available WSN (wireless sensor network has been used in a wide range of applications nowadays. Sensor networks may often relay critical data; thus, security must be a high priority. However, due to their limited computational, energy, and storage resources, sensor nodes are vulnerable to attack. So how to protect sensor nodes from attacks without raising computational capability and energy consumption is a worthwhile issue. A WAC (wireless authentication center with mixed encryption named “MEWAC” is proposed. MEWAC is based on MCU (Microcontroller Unit and WiFi (Wireless Fidelity module and uses RSA, AES (Advanced Encryption Standard, and SHA-1 (Secure Hash Algorithm 1 to provide high performance authentication and data encryption services for sensor nodes. The experimental results show that MEWAC has the advantages of low cost, low power consumption, good performance, and stability; moreover, the authentication protocol improves the security of WSN and reduces the overhead in node authentication.

  7. Encrypted data inquiries using chained perfect hashing (CPH)

    Science.gov (United States)

    Kaabneh, Khalid; Tarawneh, Hassan; Alhadid, Issam

    2017-09-01

    Cryptography is the practice of transforming data to indecipherable by a third party, unless a particular piece of secret information is made available to them. Data encryption has been paid a great attention to protect data. As data sizes are growing, so does the need for efficient data search while being encrypted to protect it during transmission and storage. This research is based on our previous and continuous work to speed up and enhance global heuristic search on an encrypted data. This research is using chained hashing approach to reduce the search time and decrease the collision rate which most search techniques suffers from. The results were very encouraging and will be discussed in the experimental results section.

  8. Image encryption using random sequence generated from generalized information domain

    International Nuclear Information System (INIS)

    Zhang Xia-Yan; Wu Jie-Hua; Zhang Guo-Ji; Li Xuan; Ren Ya-Zhou

    2016-01-01

    A novel image encryption method based on the random sequence generated from the generalized information domain and permutation–diffusion architecture is proposed. The random sequence is generated by reconstruction from the generalized information file and discrete trajectory extraction from the data stream. The trajectory address sequence is used to generate a P-box to shuffle the plain image while random sequences are treated as keystreams. A new factor called drift factor is employed to accelerate and enhance the performance of the random sequence generator. An initial value is introduced to make the encryption method an approximately one-time pad. Experimental results show that the random sequences pass the NIST statistical test with a high ratio and extensive analysis demonstrates that the new encryption scheme has superior security. (paper)

  9. Cryptanalysis of an image encryption algorithm based on DNA encoding

    Science.gov (United States)

    Akhavan, A.; Samsudin, A.; Akhshani, A.

    2017-10-01

    Recently an image encryption algorithm based on DNA encoding and the Elliptic Curve Cryptography (ECC) is proposed. This paper aims to investigate the security the DNA-based image encryption algorithm and its resistance against chosen plaintext attack. The results of the analysis demonstrate that security of the algorithm mainly relies on one static shuffling step, with a simple confusion operation. In this study, a practical plain image recovery method is proposed, and it is shown that the images encrypted with the same key could easily be recovered using the suggested cryptanalysis method with as low as two chosen plain images. Also, a strategy to improve the security of the algorithm is presented in this paper.

  10. An image encryption algorithm utilizing julia sets and hilbert curves.

    Directory of Open Access Journals (Sweden)

    Yuanyuan Sun

    Full Text Available Image encryption is an important and effective technique to protect image security. In this paper, a novel image encryption algorithm combining Julia sets and Hilbert curves is proposed. The algorithm utilizes Julia sets' parameters to generate a random sequence as the initial keys and gets the final encryption keys by scrambling the initial keys through the Hilbert curve. The final cipher image is obtained by modulo arithmetic and diffuse operation. In this method, it needs only a few parameters for the key generation, which greatly reduces the storage space. Moreover, because of the Julia sets' properties, such as infiniteness and chaotic characteristics, the keys have high sensitivity even to a tiny perturbation. The experimental results indicate that the algorithm has large key space, good statistical property, high sensitivity for the keys, and effective resistance to the chosen-plaintext attack.

  11. An image encryption algorithm utilizing julia sets and hilbert curves.

    Science.gov (United States)

    Sun, Yuanyuan; Chen, Lina; Xu, Rudan; Kong, Ruiqing

    2014-01-01

    Image encryption is an important and effective technique to protect image security. In this paper, a novel image encryption algorithm combining Julia sets and Hilbert curves is proposed. The algorithm utilizes Julia sets' parameters to generate a random sequence as the initial keys and gets the final encryption keys by scrambling the initial keys through the Hilbert curve. The final cipher image is obtained by modulo arithmetic and diffuse operation. In this method, it needs only a few parameters for the key generation, which greatly reduces the storage space. Moreover, because of the Julia sets' properties, such as infiniteness and chaotic characteristics, the keys have high sensitivity even to a tiny perturbation. The experimental results indicate that the algorithm has large key space, good statistical property, high sensitivity for the keys, and effective resistance to the chosen-plaintext attack.

  12. Remote-sensing image encryption in hybrid domains

    Science.gov (United States)

    Zhang, Xiaoqiang; Zhu, Guiliang; Ma, Shilong

    2012-04-01

    Remote-sensing technology plays an important role in military and industrial fields. Remote-sensing image is the main means of acquiring information from satellites, which always contain some confidential information. To securely transmit and store remote-sensing images, we propose a new image encryption algorithm in hybrid domains. This algorithm makes full use of the advantages of image encryption in both spatial domain and transform domain. First, the low-pass subband coefficients of image DWT (discrete wavelet transform) decomposition are sorted by a PWLCM system in transform domain. Second, the image after IDWT (inverse discrete wavelet transform) reconstruction is diffused with 2D (two-dimensional) Logistic map and XOR operation in spatial domain. The experiment results and algorithm analyses show that the new algorithm possesses a large key space and can resist brute-force, statistical and differential attacks. Meanwhile, the proposed algorithm has the desirable encryption efficiency to satisfy requirements in practice.

  13. Chaotic Dynamical State Variables Selection Procedure Based Image Encryption Scheme

    Directory of Open Access Journals (Sweden)

    Zia Bashir

    2017-12-01

    Full Text Available Nowadays, in the modern digital era, the use of computer technologies such as smartphones, tablets and the Internet, as well as the enormous quantity of confidential information being converted into digital form have resulted in raised security issues. This, in turn, has led to rapid developments in cryptography, due to the imminent need for system security. Low-dimensional chaotic systems have low complexity and key space, yet they achieve high encryption speed. An image encryption scheme is proposed that, without compromising the security, uses reasonable resources. We introduced a chaotic dynamic state variables selection procedure (CDSVSP to use all state variables of a hyper-chaotic four-dimensional dynamical system. As a result, less iterations of the dynamical system are required, and resources are saved, thus making the algorithm fast and suitable for practical use. The simulation results of security and other miscellaneous tests demonstrate that the suggested algorithm excels at robustness, security and high speed encryption.

  14. An Efficient Symmetric Searchable Encryption Scheme for Cloud Storage

    Directory of Open Access Journals (Sweden)

    Xiuxiu Jiang

    2017-05-01

    Full Text Available Symmetric searchable encryption for cloud storage enables users to retrieve the documents they want in a privacy-preserving way, which has become a hotspot of research. In this paper, we propose an efficient keyword search scheme over encrypted cloud data. We firstly adopt a structure named as inverted matrix (IM to build search index. The IM is consisted of index vectors, each of which is associated with a keyword. Then we map a keyword to an address used to locate the corresponding index vector. Finally, we mask index vectors with pseudo-random bits to obtain an encrypted enlarged inverted matrix (EEIM. Through the security analysis and experimental evaluation, we demonstrate the privacy and efficiency of our scheme respectively. In addition, we further consider two extended practical search situations, i.e., occurrence queries and dynamic user management, and then give two relevant schemes.

  15. A first approach on an RGB image encryption

    Science.gov (United States)

    Kumar, Manish; Mishra, D. C.; Sharma, R. K.

    2014-01-01

    Image encryption and decryption are essential for securing images from various types of security attacks. In this paper, we have proposed a first approach for an RGB image encryption and decryption using two stage random matrix affine cipher associated with discrete wavelet transformation. Earlier proposed schemes for encoding and decoding of images discussed only about the keys, but in our proposed approach, keys and the arrangement of RMAC parameters are mandatory. We have also formulated a formula for all the possible range to choose keys for encrypting and decrypting an RGB image. Computer simulation with a standard example and result is given to analyze the capability of the proposed approach. We have given security analysis and comparison between our proposed technique and others to support for robustness of the approach. This approach can be used for transmission of image data efficiently and securely.

  16. Digital Sound Encryption with Logistic Map and Number Theoretic Transform

    Science.gov (United States)

    Satria, Yudi; Gabe Rizky, P. H.; Suryadi, MT

    2018-03-01

    Digital sound security has limits on encrypting in Frequency Domain. Number Theoretic Transform based on field (GF 2521 – 1) improve and solve that problem. The algorithm for this sound encryption is based on combination of Chaos function and Number Theoretic Transform. The Chaos function that used in this paper is Logistic Map. The trials and the simulations are conducted by using 5 different digital sound files data tester in Wave File Extension Format and simulated at least 100 times each. The key stream resulted is random with verified by 15 NIST’s randomness test. The key space formed is very big which more than 10469. The processing speed of algorithm for encryption is slightly affected by Number Theoretic Transform.

  17. Optical cryptanalysis of DRPE-based encryption systems

    Science.gov (United States)

    Qin, Wan; He, Wenqi; Meng, Xiangfeng; Peng, Xiang

    2009-11-01

    In this paper, we analyze the security of the classical double random phase encoding (DRPE) technique in Fourier domain, as well as its extended schemes in Fresnel and fractional Fourier domains. These schemes are resistant to bruteforce attacks, for their large key spaces. However, due to the linearity property of their encryption transformations, they are vulnerable to other attacks, such as chosen-plaintext attack and known-plaintext attack. We successfully break each of the three encryption schemes with the help of a certain quantity of plaintext-ciphertext pairs. Each attack is validated by computer simulations. The cryptanalysis indicates that, to minimize the risks, it is recommendable to introduce nonlinear operations to optical encryption systems.

  18. Algoritmi selektivnog šifrovanja - pregled sa ocenom performansi / Selective encryption algorithms: Overview with performance evaluation

    Directory of Open Access Journals (Sweden)

    Boriša Ž. Jovanović

    2010-10-01

    Full Text Available Digitalni multimedijalni sadržaj postaje zastupljeniji i sve više se razmenjuje putem računarskih mreža i javnih kanala (satelitske komunikacije, bežične mreže, internet, itd. koji predstavljaju nebezbedne medijume za prenos informacija osetljive sadržine. Sve više na značaju dobijaju mehanizmi kriptološke zaštite slika i video sadržaja. Tradicionalni sistemi kriptografske obrade u sistemima za prenos ovih vrsta informacija garantuju visok stepen sigurnosti, ali i imaju svoje nedostatke - visoku cenu implementacije i znatno kašnjenje u prenosu podataka. Pomenuti nedostaci se prevazilaze primenom algoritama selektivnog šifrovanja. / Digital multimedia content is becoming widely used and increasingly exchanged over computer network and public channels (satelite, wireless networks, Internet, etc. which is unsecured transmission media for ex changing that kind of information. Mechanisms made to encrypt image and video data are becoming more and more significant. Traditional cryptographic techniques can guarantee a high level of security but at the cost of expensive implementation and important transmission delays. These shortcomings can be exceeded using selective encryption algorithms. Introduction In traditional image and video content protection schemes, called fully layered, the whole content is first compressed. Then, the compressed bitstream is entirely encrypted using a standard cipher (DES - Data Encryption Algorithm, IDEA - International Data Encryption Algorithm, AES - Advanced Encryption Algorithm etc.. The specific characteristics of this kind of data, high-transmission rate with limited bandwidth, make standard encryption algorithms inadequate. Another limitation of traditional systems consists of altering the whole bitstream syntax which may disable some codec functionalities on the delivery site coder and decoder on the receiving site. Selective encryption is a new trend in image and video content protection. As its

  19. Secure Count Query on Encrypted Genomic Data.

    Science.gov (United States)

    Hasan, Mohammad Zahidul; Rahman Mahdi, Md Safiur; Sadat, Md Nazmus; Mohammed, Noman

    2018-03-14

    Human genomic information can yield more effective healthcare by guiding medical decisions. Therefore, genomics research is gaining popularity as it can identify potential correlations between a disease and a certain gene, which improves the safety and efficacy of drug treatment and can also develop more effective prevention strategies [1]. To reduce the sampling error and to increase the statistical accuracy of this type of research projects, data from different sources need to be brought together since a single organization does not necessarily possess required amount of data. In this case, data sharing among multiple organizations must satisfy strict policies (for instance, HIPAA and PIPEDA) that have been enforced to regulate privacy-sensitive data sharing. Storage and computation on the shared data can be outsourced to a third party cloud service provider, equipped with enormous storage and computation resources. However, outsourcing data to a third party is associated with a potential risk of privacy violation of the participants, whose genomic sequence or clinical profile is used in these studies. In this article, we propose a method for secure sharing and computation on genomic data in a semi-honest cloud server. In particular, there are two main contributions. Firstly, the proposed method can handle biomedical data containing both genotype and phenotype. Secondly, our proposed index tree scheme reduces the computational overhead significantly for executing secure count query operation. In our proposed method, the confidentiality of shared data is ensured through encryption, while making the entire computation process efficient and scalable for cutting-edge biomedical applications. We evaluated our proposed method in terms of efficiency on a database of Single-Nucleotide Polymorphism (SNP) sequences, and experimental results demonstrate that the execution time for a query of 50 SNPs in a database of 50000 records is approximately 5 seconds, where each

  20. Characterizing cryptographic primitives for lightweight digital image encryption

    Science.gov (United States)

    Ahmed, Farid; Resch, Cheryl L.

    2009-05-01

    We present a statistical footprint-based method to characterize several symmetric cryptographic primitives as they are used in lightweight digital image encryption. In particular, using spatial-domain histogram and frequency-domain image analysis techniques, we identify a number of metrics from the encrypted images and use them to contrast the security performance of different cryptographic primitives. For each of the metrics, the best performing cryptographic primitive is identified. Complementary primitives are then combined to result in a product cipher with better cryptographic performance.

  1. Public-Key Encryption with Non-interactive Opening

    DEFF Research Database (Denmark)

    Damgård, Ivan Bjerre; Hofheinz, Dennis; Kiltz, Eike

    2008-01-01

    We formally define the primitive of public-key encryption with non-interactive opening (PKENO), where the receiver of a ciphertext C can, convincingly and without interaction, reveal what the result was of decrypting C, without compromising the scheme’s security. This has numerous applications in...... suggested that it could be implemented based on Identity-Based Encryption. In this paper, we give direct and optimized implementations, that work without having to keep state information, unlike what one obtains from directly using IBE....

  2. Image Encryption Performance Evaluation Based on Poker Test

    Directory of Open Access Journals (Sweden)

    Shanshan Li

    2016-01-01

    Full Text Available The fast development of image encryption requires performance evaluation metrics. Traditional metrics like entropy do not consider the correlation between local pixel and its neighborhood. These metrics cannot estimate encryption based on image pixel coordinate permutation. A novel effectiveness evaluation metric is proposed in this paper to address the issue. The cipher text image is transformed to bit stream. Then, Poker Test is implemented. The proposed metric considers the neighbor correlations of image by neighborhood selection and clip scan. The randomness of the cipher text image is tested by calculating the chi-square test value. Experiment results verify the efficiency of the proposed metrics.

  3. File compression and encryption based on LLS and arithmetic coding

    Science.gov (United States)

    Yu, Changzhi; Li, Hengjian; Wang, Xiyu

    2018-03-01

    e propose a file compression model based on arithmetic coding. Firstly, the original symbols, to be encoded, are input to the encoder one by one, we produce a set of chaotic sequences by using the Logistic and sine chaos system(LLS), and the values of this chaotic sequences are randomly modified the Upper and lower limits of current symbols probability. In order to achieve the purpose of encryption, we modify the upper and lower limits of all character probabilities when encoding each symbols. Experimental results show that the proposed model can achieve the purpose of data encryption while achieving almost the same compression efficiency as the arithmetic coding.

  4. Joint compression and encryption using chaotically mutated Huffman trees

    Science.gov (United States)

    Hermassi, Houcemeddine; Rhouma, Rhouma; Belghith, Safya

    2010-10-01

    This paper introduces a new scheme for joint compression and encryption using the Huffman codec. A basic tree is first generated for a given message and then based on a keystream generated from a chaotic map and depending from the input message, the basic tree is mutated without changing the statistical model. Hence a symbol can be coded by more than one codeword having the same length. The security of the scheme is tested against the known plaintext attack and the brute force attack. Performance analysis including encryption/decryption speed, additional computational complexity and compression ratio are given.

  5. The security energy encryption in wireless power transfer

    Science.gov (United States)

    Sadzali, M. N.; Ali, A.; Azizan, M. M.; Albreem, M. A. M.

    2017-09-01

    This paper presents a concept of security in wireless power transfer (WPT) by applying chaos theory. Chaos theory is applied as a security system in order to safeguard the transfer of energy from a transmitter to the intended receiver. The energy encryption of the wireless power transfer utilizes chaos theory to generate the possibility of a logistic map for the chaotic security key. The simulation for energy encryption wireless power transfer system was conducted by using MATLAB and Simulink. By employing chaos theory, the chaotic key ensures the transmission of energy from transmitter to its intended receiver.

  6. Encryption of 3D Point Cloud Object with Deformed Fringe

    Directory of Open Access Journals (Sweden)

    Xin Yang

    2016-01-01

    Full Text Available A 3D point cloud object encryption method was proposed with this study. With the method, a mapping relationship between 3D coordinates was formulated and Z coordinate was transformed to deformed fringe by a phase coding method. The deformed fringe and gray image were used for encryption and decryption with simulated off-axis digital Fresnel hologram. Results indicated that the proposed method is able to accurately decrypt the coordinates and gray image of the 3D object. The method is also robust against occlusion attacks.

  7. Mononucleosis spot test

    Science.gov (United States)

    Monospot test; Heterophile antibody test; Heterophile agglutination test; Paul-Bunnell test; Forssman antibody test ... The mononucleosis spot test is done when symptoms of mononucleosis are ... Fatigue Fever Large spleen (possibly) Sore throat Tender ...

  8. 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.

  9. Threshold-based generic scheme for encrypted and tunneled Voice Flows Detection over IP Networks

    Directory of Open Access Journals (Sweden)

    M. Mazhar U. Rathore

    2015-07-01

    Full Text Available VoIP usage is rapidly growing due to its cost effectiveness, dramatic functionality over the traditional telephone network and its compatibility with public switched telephone network (PSTN. In some countries, like Pakistan, the commercial usage of VoIP is prohibited. Internet service providers (ISPs and telecommunication authorities are interested in detecting VoIP calls to either block or prioritize them. So detection of VoIP calls is important for both types of authorities. Signature-based, port-based, and pattern-based VoIP detection techniques are inefficient due to complex and confidential security and tunneling mechanisms used by VoIP. In this paper, we propose a generic, robust, efficient, and practically implementable statistical analysis-based solution to identify encrypted, non-encrypted, or tunneled VoIP media (voice flows using threshold values of flow statistical parameters. We have made a comparison with existing techniques and evaluated our system with respect to accuracy and efficiency. Our system has 97.54% direct rate and .00015% false positive rate.

  10. Cryptanalysis of a chaos-based image encryption algorithm

    International Nuclear Information System (INIS)

    Cokal, Cahit; Solak, Ercan

    2009-01-01

    A chaos-based image encryption algorithm was proposed in [Z.-H. Guan, F. Huang, W. Guan, Phys. Lett. A 346 (2005) 153]. In this Letter, we analyze the security weaknesses of the proposal. By applying chosen-plaintext and known-plaintext attacks, we show that all the secret parameters can be revealed

  11. Inter-domain Identity-based Proxy Re-encryption

    NARCIS (Netherlands)

    Tang, Qiang; Hartel, Pieter H.; Jonker, Willem

    2008-01-01

    Proxy re-encryption is a cryptographic primitive developed to delegate the decryption right from one party (the delegator) to another (the delegatee). So far, no particular research efforts have been devoted to this primitive in the inter-domain identity-based setting, where the delegator and the

  12. Evaluation of four encryption algorithms for viability, reliability and ...

    African Journals Online (AJOL)

    Data and information in storage, in transit or during processing are found in various computers and computing devices with wide range of hardware specifications. Cryptography is the knowledge of using codes to encrypt and decrypt data. It enables one to store sensitive information or transmit it across computer in a more ...

  13. 48 CFR 352.239-71 - Standard for encryption language.

    Science.gov (United States)

    2010-10-01

    ... computers, desktop computers, and other mobile devices and portable media that store or process sensitive... Information Processing Standard (FIPS) 140-2-compliant encryption (Security Requirements for Cryptographic...” in accordance with FIPS 199, Standards for Security Categorization of Federal Information and...

  14. Experimental protocol for packaging and encrypting multiple data

    International Nuclear Information System (INIS)

    Barrera, John Fredy; Trejos, Sorayda; Tebaldi, Myrian; Torroba, Roberto

    2013-01-01

    We present a novel single optical packaging and encryption (SOPE) procedure for multiple inputs. This procedure is based on a merging of a 2f scheme with a digital holographic technique to achieve efficient handling of multiple data. Through the 2f system with a random phase mask attached in its input plane, and the holographic technique, we obtain each processed input. A posteriori filtering and repositioning protocol on each hologram followed by an addition of all processed data, allows storing these data to form a single package. The final package is digitally multiplied by a second random phase mask acting as an encryption mask. In this way, the final user receives only one encrypted information unit and a single key, instead of a conventional multiple-image collecting method and several keys. Processing of individual images is cast into an optimization problem. The proposed optimization aims to simplify the handling and recovery of images while packing all of them into a single unit. The decoding process does not have the usual cross-talk or noise problems involved in other methods, as filtering and repositioning precedes the encryption step. All data are recovered in just one step at the same time by applying a simple Fourier transform operation and the decoding key. The proposed protocol takes advantage of optical processing and the versatility of the digital format. Experiments have been conducted using a Mach–Zehnder interferometer. An application is subsequently demonstrated to illustrate the feasibility of the SOPE procedure. (paper)

  15. Normalized Unconditional ϵ-Security of Private-Key Encryption

    Directory of Open Access Journals (Sweden)

    Lvqing Bi

    2017-03-01

    Full Text Available In this paper we introduce two normalized versions of non-perfect security for private-key encryption: one version in the framework of Shannon entropy, another version in the framework of Kolmogorov complexity. We prove the lower bound on either key entropy or key size for these models and study the relations between these normalized security notions.

  16. A certificateless public key encryption based return routability ...

    Indian Academy of Sciences (India)

    However, RRP has several security threats and issues. Subsequently, RRP was integrated with identity-based encryption for improvement of security. Nevertheless, it suffers from some limitations such as inherent key escrow problem, lack of key revocation, high computational load and latency while providing security.

  17. DANAIM's state-of-the-art encryption research

    DEFF Research Database (Denmark)

    Boyar, Joan

    2009-01-01

    The University of Southern Denmark together with NIST (National Institute of Standards and Technology - a non-regulatory federal agency with the US Department of Commerce) have jointly created a new invention available for advancing encryption standard S-Box applications....

  18. Lower and Upper Bounds for Deniable Public-Key Encryption

    DEFF Research Database (Denmark)

    Bendlin, Rikke; Nielsen, Jesper Buus; Nordholt, Peter Sebastian

    2011-01-01

    , the security level, the flavor and the number of rounds of the cryptosystem, it is possible to define a number of notions of deniable encryption. In this paper we prove that there does not exist any non-interactive receiver-deniable cryptosystem with better than polynomial security. This also shows...

  19. DATA HIDING IN ENCRYPTED IMAGES USING ARNOLD TRANSFORM

    Directory of Open Access Journals (Sweden)

    S. Siva Shankar

    2016-08-01

    Full Text Available Digital image steganography has several applications in information security and communication. Data hiding in encrypted images ensure that both the cover image and the secret message can be recovered at the receiver end. This work presents a novel data hiding and image encryption scheme using random diffusion and Two dimensional Arnold cat mapping transform. The secret message bits are placed in the least significant bit positions of the cover image. Then a shared key is used to generate random 8 bit random integer stream and is added to the stego image in the random diffusion step. Arnold cat mapping transformation is done to scramble the pixels. The two steps of random diffusion and Arnold transform mapping are done alternatively several times to completely encrypt the image contents. The process is reversed at the receiver end to get both the secret message and the cover image with little loss. The random diffusion step overcomes the limited period of the Arnold transform. The embedding capacity of one bit per pixel is achieved. Security analysis is carried out which shows that the encryption is highly secure. The number of collisions is low thus preventing brute force attacks. The original cover image is recoverable with minimal losses.

  20. Security Analysis of A Chaos-based Image Encryption Algorithm

    OpenAIRE

    Lian, Shiguo; Sun, Jinsheng; Wang, Zhiquan

    2006-01-01

    The security of Fridrich Image Encryption Algorithm against brute-force attack, statistical attack, known-plaintext attack and select-plaintext attack is analyzed by investigating the properties of the involved chaotic maps and diffusion functions. Based on the given analyses, some means are proposed to strengthen the overall performance of the focused cryptosystem.

  1. Public-key Encryption with Registered Keyword Search

    NARCIS (Netherlands)

    Tang, Qiang; Chen, Liqun

    Public-key Encryption with Keyword Search (PEKS) enables a server to test whether a tag from a sender and a trapdoor from a receiver contain the same keyword. In this paper, we highlight some potential security concern, i.e. a curious server is able to answer whether any selected keyword is

  2. Using secret sharing for searching in encrypted data

    NARCIS (Netherlands)

    Brinkman, Richard; Doumen, J.M.; Jonker, Willem

    When outsourcing data to an untrusted database server, the data should be encrypted. When using thin clients or low-bandwidth networks it is best to perform most of the work at the server. In this paper we present a method, inspired by secure multi-party computation, to search efficiently in

  3. Optical asymmetric image encryption using gyrator wavelet transform

    Science.gov (United States)

    Mehra, Isha; Nishchal, Naveen K.

    2015-11-01

    In this paper, we propose a new optical information processing tool termed as gyrator wavelet transform to secure a fully phase image, based on amplitude- and phase-truncation approach. The gyrator wavelet transform constitutes four basic parameters; gyrator transform order, type and level of mother wavelet, and position of different frequency bands. These parameters are used as encryption keys in addition to the random phase codes to the optical cryptosystem. This tool has also been applied for simultaneous compression and encryption of an image. The system's performance and its sensitivity to the encryption parameters, such as, gyrator transform order, and robustness has also been analyzed. It is expected that this tool will not only update current optical security systems, but may also shed some light on future developments. The computer simulation results demonstrate the abilities of the gyrator wavelet transform as an effective tool, which can be used in various optical information processing applications, including image encryption, and image compression. Also this tool can be applied for securing the color image, multispectral, and three-dimensional images.

  4. Evaluation of Four Encryption Algorithms for Viability, Reliability and ...

    African Journals Online (AJOL)

    Akorede

    utilization such as time, memory and CPU usability time which in some cases may not be in abundance to achieve the set out objective of protecting data. This work looked into the memory construction rate, different key size, CPU utilization time period and encryption ..... NET 2013 visual studio for C# windows applications.

  5. Selectively Encrypted Pull-Up Based Watermarking of Biometric data

    Science.gov (United States)

    Shinde, S. A.; Patel, Kushal S.

    2012-10-01

    Biometric authentication systems are becoming increasingly popular due to their potential usage in information security. However, digital biometric data (e.g. thumb impression) are themselves vulnerable to security attacks. There are various methods are available to secure biometric data. In biometric watermarking the data are embedded in an image container and are only retrieved if the secrete key is available. This container image is encrypted to have more security against the attack. As wireless devices are equipped with battery as their power supply, they have limited computational capabilities; therefore to reduce energy consumption we use the method of selective encryption of container image. The bit pull-up-based biometric watermarking scheme is based on amplitude modulation and bit priority which reduces the retrieval error rate to great extent. By using selective Encryption mechanism we expect more efficiency in time at the time of encryption as well as decryption. Significant reduction in error rate is expected to be achieved by the bit pull-up method.

  6. Image encryption using the two-dimensional logistic chaotic map

    Science.gov (United States)

    Wu, Yue; Yang, Gelan; Jin, Huixia; Noonan, Joseph P.

    2012-01-01

    Chaos maps and chaotic systems have been proved to be useful and effective for cryptography. In our study, the two-dimensional logistic map with complicated basin structures and attractors are first used for image encryption. The proposed method adopts the classic framework of the permutation-substitution network in cryptography and thus ensures both confusion and diffusion properties for a secure cipher. The proposed method is able to encrypt an intelligible image into a random-like one from the statistical point of view and the human visual system point of view. Extensive simulation results using test images from the USC-SIPI image database demonstrate the effectiveness and robustness of the proposed method. Security analysis results of using both the conventional and the most recent tests show that the encryption quality of the proposed method reaches or excels the current state-of-the-art methods. Similar encryption ideas can be applied to digital data in other formats (e.g., digital audio and video). We also publish the cipher MATLAB open-source-code under the web page https://sites.google.com/site/tuftsyuewu/source-code.

  7. Hot spots of mutualistic networks.

    Science.gov (United States)

    Gilarranz, Luis J; Sabatino, Malena; Aizen, Marcelo A; Bascompte, Jordi

    2015-03-01

    Incorporating interactions into a biogeographical framework may serve to understand how interactions and the services they provide are distributed in space. We begin by simulating the spatiotemporal dynamics of realistic mutualistic networks inhabiting spatial networks of habitat patches. We proceed by comparing the predicted patterns with the empirical results of a set of pollination networks in isolated hills of the Argentinian Pampas. We first find that one needs to sample up to five times as much area to record interactions as would be needed to sample the same proportion of species. Secondly, we find that peripheral patches have fewer interactions and harbour less nested networks - therefore potentially less resilient communities - compared to central patches. Our results highlight the important role played by the structure of dispersal routes on the spatial distribution of community patterns. This may help to understand the formation of biodiversity hot spots. © 2014 The Authors. Journal of Animal Ecology © 2014 British Ecological Society.

  8. Fatigue Strength and Related Characteristics of Aircraft Joints I : Comparison of Spot-Weld and Rivet Patterns in 24s-t Alclad and 75s-t Alclad

    Science.gov (United States)

    Russell, H W; Jackson, L R; Grover, H J; Beaver, W W

    1944-01-01

    Report contains detailed results of a number of fatigue tests on spot-welded joints in aluminum alloys. The tests described include: (1) fatigue tests on spot-welded lap joints in sheets of unequal thickness of alclad 24s-t. These tests indicate that the fatigue strength of a spot-welded joint in sheets of two different gages is slightly higher than that of a similar joint in two sheets of the thinner gage but definitely lower than that of a similar joint in two sheets of the thicker gage. (2) Fatigue tests on spot-welded alclad 75s-t spot-welded lap-joint specimens of alclad 75s-t were not any stronger in fatigue than similar specimens of alclad 24s-t. (3) Fatigue tests on lap-joint specimens spot -welded after various surface preparations--these included ac welding wire-brushed surfaces, dc welding wire-brushed surfaces, and dc welding chemically cleaned surfaces. While the ac welds were strongest statically, the dc welds on wire-brushed surfaces were strongest in fatigue. Specimens prepared in this way were very nearly as strong as the best riveted specimens tested for comparison. (4) Fatigue tests on specimens spot-welded with varying voltage so as to include a wide range of static spot-weld strengths. The fatigue strengths were in the same order as the static strengths but showed less range. (author)

  9. Cotton-wool spots.

    Science.gov (United States)

    Brown, G C; Brown, M M; Hiller, T; Fischer, D; Benson, W E; Magargal, L E

    1985-01-01

    A series of 24 consecutive patients presenting with a fundus picture characterized by a predominance of cotton-wool spots, or a single cotton-wool spot, is reported. Excluded were patients with known diabetes mellitus. Etiologic conditions found included previously undiagnosed diabetes mellitus in five patients, systemic hypertension in five patients, cardiac valvular disease in two patients, radiation retinopathy in two patients, and severe carotid artery obstruction in two patients. Dermatomyositis, systemic lupus erythematosus, polyarteritis nodosa, leukemia, AIDS, Purtscher's retinopathy, metastatic carcinoma, intravenous drug abuse, partial central retinal artery obstruction, and giant cell arteritis were each found in one patient. In only one patient did a systemic workup fail to reveal an underlying cause. The presence of even one cotton-wool spot in an otherwise normal fundus necessitates an investigation to ascertain systemic etiologic factors.

  10. The fractal nature of vacuum arc cathode spots

    International Nuclear Information System (INIS)

    Anders, Andre

    2005-01-01

    Cathode spot phenomena show many features of fractals, for example self-similar patterns in the emitted light and arc erosion traces. Although there have been hints on the fractal nature of cathode spots in the literature, the fractal approach to spot interpretation is underutilized. In this work, a brief review of spot properties is given, touching the differences between spot type 1 (on cathodes surfaces with dielectric layers) and spot type 2 (on metallic, clean surfaces) as well as the known spot fragment or cell structure. The basic properties of self-similarity, power laws, random colored noise, and fractals are introduced. Several points of evidence for the fractal nature of spots are provided. Specifically power laws are identified as signature of fractal properties, such as spectral power of noisy arc parameters (ion current, arc voltage, etc) obtained by fast Fourier transform. It is shown that fractal properties can be observed down to the cutoff by measurement resolution or occurrence of elementary steps in physical processes. Random walk models of cathode spot motion are well established: they go asymptotically to Brownian motion for infinitesimal step width. The power spectrum of the arc voltage noise falls as 1/f 2 , where f is frequency, supporting a fractal spot model associated with Brownian motion

  11. Analysis of double random phase encryption from a key-space perspective

    Science.gov (United States)

    Monaghan, David S.; Situ, Guohai; Ryle, James; Gopinathan, Unnikrishnan; Naughton, Thomas J.; Sheridan, John T.

    2007-09-01

    The main advantage of the double random phase encryption technique is its physical implementation however to allow us to analyse its behaviour we perform the encryption/decryption numerically. A typically strong encryption scheme will have an extremely large key-space, which will make the probable success of any brute force attack on that algorithm miniscule. Traditionally, designers of optical image encryption systems only demonstrate how a small number of arbitrary keys cannot decrypt a chosen encrypted image in their system. We analyse this algorithm from a key-space perspective. The key-space of an encryption algorithm can be defined as the set of possible keys that can be used to encode data using that algorithm. For a range of problem instances we plot the distribution of decryption errors in the key-space indicating the lack of feasibility of a simple brute force attack.

  12. Separable Reversible Data Hiding in Encrypted Signals with Public Key Cryptography

    Directory of Open Access Journals (Sweden)

    Wei-Liang Tai

    2018-01-01

    Full Text Available We propose separable reversible data hiding in an encrypted signal with public key cryptography. In our separable framework, the image owner encrypts the original image by using a public key. On receipt of the encrypted signal, the data-hider embeds data in it by using a data-hiding key. The image decryption and data extraction are independent and separable at the receiver side. Even though the receiver, who has only the data-hiding key, does not learn about the decrypted content, he can extract data from the received marked encrypted signal. However, the receiver who has only the private key cannot extract the embedded data, but he can directly decrypt the received marked encrypted signal to obtain the original image without any error. Compared with other schemes using a cipher stream to encrypt the image, the proposed scheme is more appropriate for cloud services without degrading the security level.

  13. Nano-encrypted Morse code: a versatile approach to programmable and reversible nanoscale assembly and disassembly.

    Science.gov (United States)

    Wong, Ngo Yin; Xing, Hang; Tan, Li Huey; Lu, Yi

    2013-02-27

    While much work has been devoted to nanoscale assembly of functional materials, selective reversible assembly of components in the nanoscale pattern at selective sites has received much less attention. Exerting such a reversible control of the assembly process will make it possible to fine-tune the functional properties of the assembly and to realize more complex designs. Herein, by taking advantage of different binding affinities of biotin and desthiobiotin toward streptavidin, we demonstrate selective and reversible decoration of DNA origami tiles with streptavidin, including revealing an encrypted Morse code "NANO" and reversible exchange of uppercase letter "I" with lowercase "i". The yields of the conjugations are high (>90%), and the process is reversible. We expect this versatile conjugation technique to be widely applicable with different nanomaterials and templates.

  14. A Fingerprint Image Encryption Scheme Based on Hyperchaotic Rössler Map

    Directory of Open Access Journals (Sweden)

    F. Abundiz-Pérez

    2016-01-01

    Full Text Available Currently, biometric identifiers have been used to identify or authenticate users in a biometric system to increase the security in access control systems. Nevertheless, there are several attacks on the biometric system to steal and recover the user’s biometric trait. One of the most powerful attacks is extracting the fingerprint pattern when it is transmitted over communication lines between modules. In this paper, we present a novel fingerprint image encryption scheme based on hyperchaotic Rössler map to provide high security and secrecy in user’s biometric trait, avoid identity theft, and increase the robustness of the biometric system. A complete security analysis is presented to justify the secrecy of the biometric trait by using our proposed scheme at statistical level with 100% of NPCR, low correlation, and uniform histograms. Therefore, it can be used in secure biometric access control systems.

  15. Black Box Traceable Ciphertext Policy Attribute-Based Encryption Scheme

    Directory of Open Access Journals (Sweden)

    Xingbing Fu

    2015-08-01

    Full Text Available In the existing attribute-based encryption (ABE scheme, the authority (i.e., private key generator (PKG is able to calculate and issue any user’s private key, which makes it completely trusted, which severely influences the applications of the ABE scheme. To mitigate this problem, we propose the black box traceable ciphertext policy attribute-based encryption (T-CP-ABE scheme in which if the PKG re-distributes the users’ private keys for malicious uses, it might be caught and sued. We provide a construction to realize the T-CP-ABE scheme in a black box model. Our scheme is based on the decisional bilinear Diffie-Hellman (DBDH assumption in the standard model. In our scheme, we employ a pair (ID, S to identify a user, where ID denotes the identity of a user and S denotes the attribute set associated with her.

  16. APE: Authenticated Permutation-Based Encryption for Lightweight Cryptography

    DEFF Research Database (Denmark)

    Andreeva, Elena; Bilgin, Begül; Bogdanov, Andrey

    2015-01-01

    The domain of lightweight cryptography focuses on cryptographic algorithms for extremely constrained devices. It is very costly to avoid nonce reuse in such environments, because this requires either a hardware source of randomness, or non-volatile memory to store a counter. At the same time, a lot...... of cryptographic schemes actually require the nonce assumption for their security. In this paper, we propose APE as the first permutation-based authenticated encryption scheme that is resistant against nonce misuse. We formally prove that APE is secure, based on the security of the underlying permutation......, and Spongent. For any of these permutations, an implementation that supports both encryption and decryption requires less than 1.9 kGE and 2.8 kGE for 80-bit and 128-bit security levels, respectively....

  17. End-to-End Encryption for Personal Telehealth Systems.

    Science.gov (United States)

    Ollerer, Gerald; Mense, Alexander

    2014-01-01

    Data from personal health devices is expected to be an important part of personalized care in future, but communication frameworks for such data create new challenges for security and privacy. Continua Health Alliance has been very active and successful in defining guidelines and a reference architecture for transmitting personal health device data based on well-known international standards. But looking at the security definitions, the concepts are still facing open issues and weaknesses like identity management or missing end-2end (E2E) encryption. This paper presents an approach for an E2E encryption framework based on Continua's reference architecture and the underlying base standards. It introduces the basic process and proposes necessary extensions to the architecture as well as to the standardized protocols of ISO/IEEE 11073 and HL7 version 2.

  18. GENERALIZED MATRIXES OF GALOIS PROTOCOLS EXCHANGE ENCRYPTION KEYS

    Directory of Open Access Journals (Sweden)

    Anatoly Beletsky

    2016-03-01

    Full Text Available The methods of construction of matrix formation the secret protocols legalized subscribers of public communications networks encryption keys. Based key exchange protocols laid asymmetric cryptography algorithms. The solution involves the calculation of one-way functions and is based on the use of generalized Galois arrays of isomorphism relationship with forming elements, and depending on the selected irreducible polynomial generating matrix. A simple method for constructing generalized Galois matrix by the method of filling the diagonal. In order to eliminate the isomorphism of Galois arrays and their constituent elements, limiting the possibility of building one-way functions, Galois matrix subjected to similarity transformation carried out by means of permutation matrices. The variant of the organization of the algebraic attacks on encryption keys sharing protocols and discusses options for easing the consequences of an attack.

  19. Generating Private Recommendations Efficiently Using Homomorphic Encryption and Data Packing

    DEFF Research Database (Denmark)

    Erkin, Zekeriya; Veugen, Thijs; Toft, Tomas

    2012-01-01

    Recommender systems have become an important tool for personalization of online services. Generating recommendations in online services depends on privacy-sensitive data collected from the users. Traditional data protection mechanisms focus on access control and secure transmission, which provide...... them under encryption to generate recommendations. By introducing a semitrusted third party and using data packing, we construct a highly efficient system that does not require the active participation of the user. We also present a comparison protocol, which is the first one to the best of our...... security only against malicious third parties, but not the service provider. This creates a serious privacy risk for the users. In this paper, we aim to protect the private data against the service provider while preserving the functionality of the system. We propose encrypting private data and processing...

  20. Experimental color encryption in a joint transform correlator architecture

    Energy Technology Data Exchange (ETDEWEB)

    Tebaldi, Myrian; Amaya, Dafne; Torroba, Roberto [Centro de Investigaciones Opticas (CONICET La Plata-CIC) and UID OPTIMO, Facultad Ingenieria, Universidad Nacional de La Plata (Argentina); Horrillo, Sergi; Perez-Cabre, Elisabet; Millan, Maria S [Departamento de Optica y Optometria de la Universidad Politecnica de Cataluna, Terrasa (Spain); Bolognini, Nestor, E-mail: myrianc@ciop.unlp.edu.ar

    2011-01-01

    We present an experimental color image encryption by using a photorefractive crystal and a joint transform correlator (JTC) architecture. We achieve the color storing by changing the illumination wavelength. One JTC aperture has the input image information corresponding to a determined color channel bonded to a random phase mask (object aperture), and the other JTC aperture contains the key code mask. The joint power spectrum is stored in a photorefractive crystal. Each color data is stored as a modulation of birefringence in this photosensitive medium. The adequate wavelength change produces a corresponding power spectrum modification that avoids image encryption cross talk in the read out step. An analysis in terms of the sensitivity of the photorefractive silenite crystal for different recording wavelengths is carried out. It should be highlighted that the multiplexed power spectrum shows neither the multiplexing operation nor the amount of stored information increasing the system security. We present experimental results that support our approach

  1. Chaotic Image Encryption Algorithm Based on Circulant Operation

    Directory of Open Access Journals (Sweden)

    Xiaoling Huang

    2013-01-01

    Full Text Available A novel chaotic image encryption scheme based on the time-delay Lorenz system is presented in this paper with the description of Circulant matrix. Making use of the chaotic sequence generated by the time-delay Lorenz system, the pixel permutation is carried out in diagonal and antidiagonal directions according to the first and second components. Then, a pseudorandom chaotic sequence is generated again from time-delay Lorenz system using all components. Modular operation is further employed for diffusion by blocks, in which the control parameter is generated depending on the plain-image. Numerical experiments show that the proposed scheme possesses the properties of a large key space to resist brute-force attack, sensitive dependence on secret keys, uniform distribution of gray values in the cipher-image, and zero correlation between two adjacent cipher-image pixels. Therefore, it can be adopted as an effective and fast image encryption algorithm.

  2. Exploring Information Security and Shared Encrypted Spaces in Libraries

    Directory of Open Access Journals (Sweden)

    Keith Engwall

    2015-07-01

    Full Text Available Libraries are sensitive to the need to protect patron data, but may not take measures to protect the data of the library. However, in an increasingly collaborative online environment, the protection of data is a concern that merits attention. As a follow-up to a new patron privacy policy, the Oakland University William Beaumont Medical Library evaluated information security tools for use in day-to-day operations in an attempt to identify ways to protect private information in communication and shared storage, as well as a means to manage passwords in a collaborative team environment. This article provides an overview of encryption measures, outlines the Medical Library’s evaluation of encryption tools, and reflects on the benefits and challenges in their adoption and use.

  3. Studi Perbandingan Antara Metode Probabilistic Encryption Dengan Metode Rivest-Shamir-Adleman

    OpenAIRE

    Nababan, Ferry Heriston

    2011-01-01

    A study has been made about the comparison between the methods Probabilistic Encryption with RSA method (Rivest-Shamir-Adleman). Many algorithms used in the manufacture of encryption key data, which often lead to confusion in applying the appropriate algorithm to design an encryption key and decryption key data. To apply / display the results of a study on the Implementation System into shape, then built a support system of applying the above algorithm using a programming language. The al...

  4. An improved arbitrated quantum signature protocol based on the key-controlled chained CNOT encryption

    Science.gov (United States)

    Zhang, Long; Sun, Hong-Wei; Zhang, Ke-Jia; Jia, Heng-Yue

    2017-03-01

    In this paper, a new quantum encryption based on the key-controlled chained CNOT operations, which is named KCCC encryption, is proposed. With the KCCC encryption, an improved arbitrated quantum signature (AQS) protocol is presented. Compared with the existing protocols, our protocol can effectively prevent forgery attacks and disavowal attacks. Moreover, only single state is required in the protocol. We hope it is helpful to further research in the design of AQS protocols in future.

  5. WSES: HIGH SECURED DATA ENCRYPTION AND AUTHENTICATION USING WEAVING, ROTATION AND FLIPPING

    Directory of Open Access Journals (Sweden)

    A. Yesu Raj

    2015-12-01

    Full Text Available Data security is the very important part in the network data communication. Avoidance of the information hacking and steeling are very challenging part for network data communication. Now-a-days people are using many encryption and decryption techniques for data security. But all encryption and decryption techniques are having more time occupation or less security for the process. This paper proposed high level security approach to encryption and decryption for data security. Two levels of securities are used in this proposed method. First one is data encryption and the second one is hash value generation. The proposed Weaving based Superior Encryption Standard (WSES uses a novel weaving based approach. The weaving array generation is done by Elementary Number Theory Notation (ENTN method. The weaving array has multiple private keys for XOR encryption. After encryption the error value is extracted from the encrypted array and weaving array. This error value is sent to the other side. The novel approach for hash value generation uses the encrypted array. After encryption, the encrypted array is rotated into four degrees and each degree data are converted to vector format and arranged on by one under the vector. Finally a 2D Rotational Encryption Matrix (REM is obtained. After this process a REM copy is converted to mirror flip and it is need as Flipped Matrix (FM. The FM is concatenated under the REM and converted to vector using the zigzag operation. Finally this process gives two bytes hash value from the vector. This proposed method executes very fast and provide high security. This method is much reliable to small size applications and also used for any type of data security.

  6. Hardware realization of chaos based block cipher for image encryption

    KAUST Repository

    Barakat, Mohamed L.

    2011-12-01

    Unlike stream ciphers, block ciphers are very essential for parallel processing applications. In this paper, the first hardware realization of chaotic-based block cipher is proposed for image encryption applications. The proposed system is tested for known cryptanalysis attacks and for different block sizes. When implemented on Virtex-IV, system performance showed high throughput and utilized small area. Passing successfully in all tests, our system proved to be secure with all block sizes. © 2011 IEEE.

  7. Three Tier Encryption Algorithm For Secure File Transfer

    OpenAIRE

    Balakrishnan, Bhargav

    2011-01-01

    This encryption algorithm is mainly designed for having a secure file transfer in the low privilege servers and as well as in a secured environment too. This methodology will be implemented in the data center and other important data transaction sectors of the organisation where the encoding process of the software will be done by the database administrator or system administrators and his trusted clients will have decoding process of the software. This software will not be circulated to the ...

  8. Hyperchaotic encryption based on multi-scroll piecewise linear Systems

    Czech Academy of Sciences Publication Activity Database

    García-Martínez, M.; Ontanon-García, L.J.; Campos-Cantón, E.; Čelikovský, Sergej

    2015-01-01

    Roč. 270, č. 1 (2015), s. 413-424 ISSN 0096-3003 R&D Projects: GA ČR GA13-20433S Institutional support: RVO:67985556 Keywords : Hyperchaotic encryption * Piecewise linear systems * Stream cipher * Pseudo - random bit generator * Chaos theory * Multi-scrollattractors Subject RIV: BC - Control Systems Theory Impact factor: 1.345, year: 2015 http://library.utia.cas.cz/separaty/2015/TR/celikovsky-0446895.pdf

  9. Optics based biometric encryption using log polar transform

    Science.gov (United States)

    Saini, Nirmala; Sinha, Aloka

    2010-01-01

    We propose an optics based biometric encryption technique using log polar transform. In this method, the key of the encryption process has been linked to the fingerprint of the enrolled person. The order of fractional Fourier transform and the seed values of the chaotic random phase masks in combination act as the key for the encryption process. In order to link the combined key to the fingerprint, a lookup table has been formed by the key and the log polar transform of the fingerprint. The linking algorithm not only encrypts the image of the enrolled person but also authenticates the input image. The main advantage of this method is its capability to retrieve the same key in the decryption process by using the live fingerprint. The key is not required to be communicated to the receiver side. The retrieval of the image is possible only when the live fingerprint of the enrolled person is presented at the decryption side. The real life fingerprints have been used to demonstrate the proposed technique. Simulations have been performed on the Matlab platform to validate the proposed technique. The signal to noise ratio and mean square error has been calculated in order to support the proposed technique. The effect of the rotation and the scaling of the fingerprints have been studied to check the key retrieval from the live fingerprint of the enrolled person. The study of the different whorl types of fingerprint of different persons has also been done to check the efficacy of the key retrieval from the whorl types of the live fingerprints of different person.

  10. Email authentication using symmetric and asymmetric key algorithm encryption

    Science.gov (United States)

    Halim, Mohamad Azhar Abdul; Wen, Chuah Chai; Rahmi, Isredza; Abdullah, Nurul Azma; Rahman, Nurul Hidayah Ab.

    2017-10-01

    Protection of sensitive or classified data from unauthorized access, hackers and other personals is virtue. Storage of data is done in devices such as USB, external hard disk, laptops, I-Pad or at cloud. Cloud computing presents with both ups and downs. However, storing information elsewhere increases risk of being attacked by hackers. Besides, the risk of losing the device or being stolen is increased in case of storage in portable devices. There are array of mediums of communications and even emails used to send data or information but these technologies come along with severe weaknesses such as absence of confidentiality where the message sent can be altered and sent to the recipient. No proofs are shown to the recipient that the message received is altered. The recipient would not find out unless he or she checks with the sender. Without encrypted of data or message, sniffing tools and software can be used to hack and read the information since it is in plaintext. Therefore, an electronic mail authentication is proposed, namely Hybrid Encryption System (HES). The security of HES is protected using asymmetric and symmetric key algorithms. The asymmetric algorithm is RSA and symmetric algorithm is Advance Encryption Standard. With the combination for both algorithms in the HES may provide the confidentiality and authenticity to the electronic documents send from the sender to the recipient. In a nutshell, the HES will help users to protect their valuable documentation and data from illegal third party user.

  11. Enhanced K-means clustering with encryption on cloud

    Science.gov (United States)

    Singh, Iqjot; Dwivedi, Prerna; Gupta, Taru; Shynu, P. G.

    2017-11-01

    This paper tries to solve the problem of storing and managing big files over cloud by implementing hashing on Hadoop in big-data and ensure security while uploading and downloading files. Cloud computing is a term that emphasis on sharing data and facilitates to share infrastructure and resources.[10] Hadoop is an open source software that gives us access to store and manage big files according to our needs on cloud. K-means clustering algorithm is an algorithm used to calculate distance between the centroid of the cluster and the data points. Hashing is a algorithm in which we are storing and retrieving data with hash keys. The hashing algorithm is called as hash function which is used to portray the original data and later to fetch the data stored at the specific key. [17] Encryption is a process to transform electronic data into non readable form known as cipher text. Decryption is the opposite process of encryption, it transforms the cipher text into plain text that the end user can read and understand well. For encryption and decryption we are using Symmetric key cryptographic algorithm. In symmetric key cryptography are using DES algorithm for a secure storage of the files. [3

  12. Security on Cloud Revocation Authority using Identity Based Encryption

    Science.gov (United States)

    Rajaprabha, M. N.

    2017-11-01

    As due to the era of cloud computing most of the people are saving there documents, files and other things on cloud spaces. Due to this security over the cloud is also important because all the confidential things are there on the cloud. So to overcome private key infrastructure (PKI) issues some revocable Identity Based Encryption (IBE) techniques are introduced which eliminates the demand of PKI. The technique introduced is key update cloud service provider which is having two issues in it and they are computation and communication cost is high and second one is scalability issue. So to overcome this problem we come along with the system in which the Cloud Revocation Authority (CRA) is there for the security which will only hold the secret key for each user. And the secret key was send with the help of advanced encryption standard security. The key is encrypted and send to the CRA for giving the authentication to the person who wants to share the data or files or for the communication purpose. Through that key only the other user will able to access that file and if the user apply some invalid key on the particular file than the information of that user and file is send to the administrator and administrator is having rights to block that person of black list that person to use the system services.

  13. Hybrid Cryptosystem Using Tiny Encryption Algorithm and LUC Algorithm

    Science.gov (United States)

    Rachmawati, Dian; Sharif, Amer; Jaysilen; Andri Budiman, Mohammad

    2018-01-01

    Security becomes a very important issue in data transmission and there are so many methods to make files more secure. One of that method is cryptography. Cryptography is a method to secure file by writing the hidden code to cover the original file. Therefore, if the people do not involve in cryptography, they cannot decrypt the hidden code to read the original file. There are many methods are used in cryptography, one of that method is hybrid cryptosystem. A hybrid cryptosystem is a method that uses a symmetric algorithm to secure the file and use an asymmetric algorithm to secure the symmetric algorithm key. In this research, TEA algorithm is used as symmetric algorithm and LUC algorithm is used as an asymmetric algorithm. The system is tested by encrypting and decrypting the file by using TEA algorithm and using LUC algorithm to encrypt and decrypt the TEA key. The result of this research is by using TEA Algorithm to encrypt the file, the cipher text form is the character from ASCII (American Standard for Information Interchange) table in the form of hexadecimal numbers and the cipher text size increase by sixteen bytes as the plaintext length is increased by eight characters.

  14. Query-Biased Preview over Outsourced and Encrypted Data

    Directory of Open Access Journals (Sweden)

    Ningduo Peng

    2013-01-01

    document to check if it contains the desired content. An informative query-biased preview feature, as applied in modern search engine, could help the users to learn about the content without downloading the entire document. However, when the data are encrypted, securely extracting a keyword-in-context snippet from the data as a preview becomes a challenge. Based on private information retrieval protocol and the core concept of searchable encryption, we propose a single-server and two-round solution to securely obtain a query-biased snippet over the encrypted data from the server. We achieve this novel result by making a document (plaintext previewable under any cryptosystem and constructing a secure index to support dynamic computation for a best matched snippet when queried by some keywords. For each document, the scheme has O(d storage complexity and O(log(d/s+s+d/s communication complexity, where d is the document size and s is the snippet length.

  15. A self-cited pixel summation based image encryption algorithm

    International Nuclear Information System (INIS)

    Ye Guo-Dong; Huang Xiao-Ling; Zhang Leo Yu; Wang Zheng-Xia

    2017-01-01

    In this paper, a novel image encryption algorithm is presented based on self-cited pixel summation. With the classical mechanism of permutation plus diffusion, a pixel summation of the plain image is employed to make a gravity influence on the pixel positions in the permutation stage. Then, for each pixel in every step of the diffusion stage, the pixel summation calculated from the permuted image is updated. The values from a chaotic sequence generated by an intertwining logistic map are selected by this summation. Consequently, the keystreams generated in both stages are dependent on both the plain image and the permuted image. Because of the sensitivity of the chaotic map to its initial conditions and the plain-image-dependent keystreams, any tiny change in the secret key or the plain image would lead to a significantly different cipher image. As a result, the proposed encryption algorithm is immune to the known plaintext attack (KPA) and the chosen plaintext attack (CPA). Moreover, experimental simulations and security analyses show that the proposed permutation-diffusion encryption scheme can achieve a satisfactory level of security. (paper)

  16. Key management and encryption under the bounded storage model.

    Energy Technology Data Exchange (ETDEWEB)

    Draelos, Timothy John; Neumann, William Douglas; Lanzone, Andrew J.; Anderson, William Erik

    2005-11-01

    There are several engineering obstacles that need to be solved before key management and encryption under the bounded storage model can be realized. One of the critical obstacles hindering its adoption is the construction of a scheme that achieves reliable communication in the event that timing synchronization errors occur. One of the main accomplishments of this project was the development of a new scheme that solves this problem. We show in general that there exist message encoding techniques under the bounded storage model that provide an arbitrarily small probability of transmission error. We compute the maximum capacity of this channel using the unsynchronized key-expansion as side-channel information at the decoder and provide tight lower bounds for a particular class of key-expansion functions that are pseudo-invariant to timing errors. Using our results in combination with Dziembowski et al. [11] encryption scheme we can construct a scheme that solves the timing synchronization error problem. In addition to this work we conducted a detailed case study of current and future storage technologies. We analyzed the cost, capacity, and storage data rate of various technologies, so that precise security parameters can be developed for bounded storage encryption schemes. This will provide an invaluable tool for developing these schemes in practice.

  17. Experimental QR code optical encryption: noise-free data recovering.

    Science.gov (United States)

    Barrera, John Fredy; Mira-Agudelo, Alejandro; Torroba, Roberto

    2014-05-15

    We report, to our knowledge for the first time, the experimental implementation of a quick response (QR) code as a "container" in an optical encryption system. A joint transform correlator architecture in an interferometric configuration is chosen as the experimental scheme. As the implementation is not possible in a single step, a multiplexing procedure to encrypt the QR code of the original information is applied. Once the QR code is correctly decrypted, the speckle noise present in the recovered QR code is eliminated by a simple digital procedure. Finally, the original information is retrieved completely free of any kind of degradation after reading the QR code. Additionally, we propose and implement a new protocol in which the reception of the encrypted QR code and its decryption, the digital block processing, and the reading of the decrypted QR code are performed employing only one device (smartphone, tablet, or computer). The overall method probes to produce an outcome far more attractive to make the adoption of the technique a plausible option. Experimental results are presented to demonstrate the practicality of the proposed security system.

  18. Testing System Encryption-Decryption Method to RSA Security Documents

    International Nuclear Information System (INIS)

    Supriyono

    2008-01-01

    A model of document protection which was tested as one of the instruments, especially text document. The principle of the document protection was how the system was able to protect the document storage and transfer processes. Firstly, the text-formed document was encrypted; therefore, the document cannot be read for the text was transformed into random letters. The letter-randomized text was then unfolded by the description in order that the document owner was able to read it. In the recent research, the method adopted was RSA method, in which it used complicated mathematics calculation and equipped with initial protection key (with either private key or public key), thus, it was more difficult to be attacked by hackers. The system was developed by using the software of Borland Delphi 7. The results indicated that the system was capable to save and transfer the document, both via internet and intranet in the form of encrypted letter and put it back to the initial form of document by way of description. The research also tested for encrypted and decrypted process for various memory size documents. (author)

  19. Butterfly Encryption Scheme for Resource-Constrained Wireless Networks

    Directory of Open Access Journals (Sweden)

    Raghav V. Sampangi

    2015-09-01

    Full Text Available Resource-constrained wireless networks are emerging networks such as Radio Frequency Identification (RFID and Wireless Body Area Networks (WBAN that might have restrictions on the available resources and the computations that can be performed. These emerging technologies are increasing in popularity, particularly in defence, anti-counterfeiting, logistics and medical applications, and in consumer applications with growing popularity of the Internet of Things. With communication over wireless channels, it is essential to focus attention on securing data. In this paper, we present an encryption scheme called Butterfly encryption scheme. We first discuss a seed update mechanism for pseudorandom number generators (PRNG, and employ this technique to generate keys and authentication parameters for resource-constrained wireless networks. Our scheme is lightweight, as in it requires less resource when implemented and offers high security through increased unpredictability, owing to continuously changing parameters. Our work focuses on accomplishing high security through simplicity and reuse. We evaluate our encryption scheme using simulation, key similarity assessment, key sequence randomness assessment, protocol analysis and security analysis.

  20. DNA based random key generation and management for OTP encryption.

    Science.gov (United States)

    Zhang, Yunpeng; Liu, Xin; Sun, Manhui

    2017-09-01

    One-time pad (OTP) is a principle of key generation applied to the stream ciphering method which offers total privacy. The OTP encryption scheme has proved to be unbreakable in theory, but difficult to realize in practical applications. Because OTP encryption specially requires the absolute randomness of the key, its development has suffered from dense constraints. DNA cryptography is a new and promising technology in the field of information security. DNA chromosomes storing capabilities can be used as one-time pad structures with pseudo-random number generation and indexing in order to encrypt the plaintext messages. In this paper, we present a feasible solution to the OTP symmetric key generation and transmission problem with DNA at the molecular level. Through recombinant DNA technology, by using only sender-receiver known restriction enzymes to combine the secure key represented by DNA sequence and the T vector, we generate the DNA bio-hiding secure key and then place the recombinant plasmid in implanted bacteria for secure key transmission. The designed bio experiments and simulation results show that the security of the transmission of the key is further improved and the environmental requirements of key transmission are reduced. Analysis has demonstrated that the proposed DNA-based random key generation and management solutions are marked by high security and usability. Published by Elsevier B.V.

  1. Semantically Secure Symmetric Encryption with Error Correction for Distributed Storage

    Directory of Open Access Journals (Sweden)

    Juha Partala

    2017-01-01

    Full Text Available A distributed storage system (DSS is a fundamental building block in many distributed applications. It applies linear network coding to achieve an optimal tradeoff between storage and repair bandwidth when node failures occur. Additively homomorphic encryption is compatible with linear network coding. The homomorphic property ensures that a linear combination of ciphertext messages decrypts to the same linear combination of the corresponding plaintext messages. In this paper, we construct a linearly homomorphic symmetric encryption scheme that is designed for a DSS. Our proposal provides simultaneous encryption and error correction by applying linear error correcting codes. We show its IND-CPA security for a limited number of messages based on binary Goppa codes and the following assumption: when dividing a scrambled generator matrix G^ into two parts G1^ and G2^, it is infeasible to distinguish G2^ from random and to find a statistical connection between G1^ and G2^. Our infeasibility assumptions are closely related to those underlying the McEliece public key cryptosystem but are considerably weaker. We believe that the proposed problem has independent cryptographic interest.

  2. Butterfly Encryption Scheme for Resource-Constrained Wireless Networks.

    Science.gov (United States)

    Sampangi, Raghav V; Sampalli, Srinivas

    2015-09-15

    Resource-constrained wireless networks are emerging networks such as Radio Frequency Identification (RFID) and Wireless Body Area Networks (WBAN) that might have restrictions on the available resources and the computations that can be performed. These emerging technologies are increasing in popularity, particularly in defence, anti-counterfeiting, logistics and medical applications, and in consumer applications with growing popularity of the Internet of Things. With communication over wireless channels, it is essential to focus attention on securing data. In this paper, we present an encryption scheme called Butterfly encryption scheme. We first discuss a seed update mechanism for pseudorandom number generators (PRNG), and employ this technique to generate keys and authentication parameters for resource-constrained wireless networks. Our scheme is lightweight, as in it requires less resource when implemented and offers high security through increased unpredictability, owing to continuously changing parameters. Our work focuses on accomplishing high security through simplicity and reuse. We evaluate our encryption scheme using simulation, key similarity assessment, key sequence randomness assessment, protocol analysis and security analysis.

  3. Simple steps to data encryption a practical guide to secure computing

    CERN Document Server

    Loshin, Peter

    2013-01-01

    Everyone wants privacy and security online, something that most computer users have more or less given up on as far as their personal data is concerned. There is no shortage of good encryption software, and no shortage of books, articles and essays that purport to be about how to use it. Yet there is precious little for ordinary users who want just enough information about encryption to use it safely and securely and appropriately--WITHOUT having to become experts in cryptography. Data encryption is a powerful tool, if used properly. Encryption turns ordinary, readable data into what

  4. Optical multiple-image encryption based on multiplane phase retrieval and interference

    International Nuclear Information System (INIS)

    Chen, Wen; Chen, Xudong

    2011-01-01

    In this paper, we propose a new method for optical multiple-image encryption based on multiplane phase retrieval and interference. An optical encoding system is developed in the Fresnel domain. A phase-only map is iteratively extracted based on a multiplane phase retrieval algorithm, and multiple plaintexts are simultaneously encrypted. Subsequently, the extracted phase-only map is further encrypted into two phase-only masks based on a non-iterative interference algorithm. During image decryption, the advantages and security of the proposed optical cryptosystem are analyzed. Numerical results are presented to demonstrate the validity of the proposed optical multiple-image encryption method

  5. OS2: Oblivious similarity based searching for encrypted data outsourced to an untrusted domain

    Science.gov (United States)

    Pervez, Zeeshan; Ahmad, Mahmood; Khattak, Asad Masood; Ramzan, Naeem

    2017-01-01

    Public cloud storage services are becoming prevalent and myriad data sharing, archiving and collaborative services have emerged which harness the pay-as-you-go business model of public cloud. To ensure privacy and confidentiality often encrypted data is outsourced to such services, which further complicates the process of accessing relevant data by using search queries. Search over encrypted data schemes solve this problem by exploiting cryptographic primitives and secure indexing to identify outsourced data that satisfy the search criteria. Almost all of these schemes rely on exact matching between the encrypted data and search criteria. A few schemes which extend the notion of exact matching to similarity based search, lack realism as those schemes rely on trusted third parties or due to increase storage and computational complexity. In this paper we propose Oblivious Similarity based Search (OS2) for encrypted data. It enables authorized users to model their own encrypted search queries which are resilient to typographical errors. Unlike conventional methodologies, OS2 ranks the search results by using similarity measure offering a better search experience than exact matching. It utilizes encrypted bloom filter and probabilistic homomorphic encryption to enable authorized users to access relevant data without revealing results of search query evaluation process to the untrusted cloud service provider. Encrypted bloom filter based search enables OS2 to reduce search space to potentially relevant encrypted data avoiding unnecessary computation on public cloud. The efficacy of OS2 is evaluated on Google App Engine for various bloom filter lengths on different cloud configurations. PMID:28692697

  6. An Integrated Signaling-Encryption Mechanism to Reduce Error Propagation in Wireless Communications: Performance Analyses

    Energy Technology Data Exchange (ETDEWEB)

    Olama, Mohammed M [ORNL; Matalgah, Mustafa M [ORNL; Bobrek, Miljko [ORNL

    2015-01-01

    Traditional encryption techniques require packet overhead, produce processing time delay, and suffer from severe quality of service deterioration due to fades and interference in wireless channels. These issues reduce the effective transmission data rate (throughput) considerably in wireless communications, where data rate with limited bandwidth is the main constraint. In this paper, performance evaluation analyses are conducted for an integrated signaling-encryption mechanism that is secure and enables improved throughput and probability of bit-error in wireless channels. This mechanism eliminates the drawbacks stated herein by encrypting only a small portion of an entire transmitted frame, while the rest is not subject to traditional encryption but goes through a signaling process (designed transformation) with the plaintext of the portion selected for encryption. We also propose to incorporate error correction coding solely on the small encrypted portion of the data to drastically improve the overall bit-error rate performance while not noticeably increasing the required bit-rate. We focus on validating the signaling-encryption mechanism utilizing Hamming and convolutional error correction coding by conducting an end-to-end system-level simulation-based study. The average probability of bit-error and throughput of the encryption mechanism are evaluated over standard Gaussian and Rayleigh fading-type channels and compared to the ones of the conventional advanced encryption standard (AES).

  7. QR code based noise-free optical encryption and decryption of a gray scale image

    Science.gov (United States)

    Jiao, Shuming; Zou, Wenbin; Li, Xia

    2017-03-01

    In optical encryption systems, speckle noise is one major challenge in obtaining high quality decrypted images. This problem can be addressed by employing a QR code based noise-free scheme. Previous works have been conducted for optically encrypting a few characters or a short expression employing QR codes. This paper proposes a practical scheme for optically encrypting and decrypting a gray-scale image based on QR codes for the first time. The proposed scheme is compatible with common QR code generators and readers. Numerical simulation results reveal the proposed method can encrypt and decrypt an input image correctly.

  8. A new color image encryption scheme using CML and a fractional-order chaotic system.

    Directory of Open Access Journals (Sweden)

    Xiangjun Wu

    Full Text Available The chaos-based image cryptosystems have been widely investigated in recent years to provide real-time encryption and transmission. In this paper, a novel color image encryption algorithm by using coupled-map lattices (CML and a fractional-order chaotic system is proposed to enhance the security and robustness of the encryption algorithms with a permutation-diffusion structure. To make the encryption procedure more confusing and complex, an image division-shuffling process is put forward, where the plain-image is first divided into four sub-images, and then the position of the pixels in the whole image is shuffled. In order to generate initial conditions and parameters of two chaotic systems, a 280-bit long external secret key is employed. The key space analysis, various statistical analysis, information entropy analysis, differential analysis and key sensitivity analysis are introduced to test the security of the new image encryption algorithm. The cryptosystem speed is analyzed and tested as well. Experimental results confirm that, in comparison to other image encryption schemes, the new algorithm has higher security and is fast for practical image encryption. Moreover, an extensive tolerance analysis of some common image processing operations such as noise adding, cropping, JPEG compression, rotation, brightening and darkening, has been performed on the proposed image encryption technique. Corresponding results reveal that the proposed image encryption method has good robustness against some image processing operations and geometric attacks.

  9. Composite order bilinear pairing on elliptic curve for dual system encryption

    Science.gov (United States)

    Latiff, Fatin Nabila Abd; Othman, Wan Ainun Mior

    2015-10-01

    In this paper, we explore the pairing-based cryptography on elliptic curve. The security of protocols using composite order bilinear pairing on elliptic curve depends on the difficulty of factoring the number N. Here, we show how to construct composite ordinary pairing-friendly elliptic curve having the subgroup of composite order N by using Cocks-Pinch Method. We also introduce dual system encryption to transform Identity-Based Encryption (IBE) scheme built over prime-order bilinear, to composite order bilinear groups. The new Identity-Based Encryption (IBE) is secured since it uses the Dual System Encryption methodology which guaranteed full security of the new IBE system.

  10. Searchable Encryption Revisited: Consistency Properties, Relation to Anonymous IBE, and Extensions

    DEFF Research Database (Denmark)

    Abdalla, Michel; Bellare, Mihir; Catalano, Dario

    2005-01-01

    We identify and fill some gaps with regard to consistency (the extent to which false positives are produced) for public-key encryption with keyword search (PEKS). We define computational and statistical relaxations of the existing notion of perfect consistency, show that the scheme of [7] is comp......We identify and fill some gaps with regard to consistency (the extent to which false positives are produced) for public-key encryption with keyword search (PEKS). We define computational and statistical relaxations of the existing notion of perfect consistency, show that the scheme of [7...... HIBE, public-key encryption with temporary keyword search, and identity-based encryption with keyword search....

  11. Batch Image Encryption Using Generated Deep Features Based on Stacked Autoencoder Network

    Directory of Open Access Journals (Sweden)

    Fei Hu

    2017-01-01

    Full Text Available Chaos-based algorithms have been widely adopted to encrypt images. But previous chaos-based encryption schemes are not secure enough for batch image encryption, for images are usually encrypted using a single sequence. Once an encrypted image is cracked, all the others will be vulnerable. In this paper, we proposed a batch image encryption scheme into which a stacked autoencoder (SAE network was introduced to generate two chaotic matrices; then one set is used to produce a total shuffling matrix to shuffle the pixel positions on each plain image, and another produces a series of independent sequences of which each is used to confuse the relationship between the permutated image and the encrypted image. The scheme is efficient because of the advantages of parallel computing of SAE, which leads to a significant reduction in the run-time complexity; in addition, the hybrid application of shuffling and confusing enhances the encryption effect. To evaluate the efficiency of our scheme, we compared it with the prevalent “logistic map,” and outperformance was achieved in running time estimation. The experimental results and analysis show that our scheme has good encryption effect and is able to resist brute-force attack, statistical attack, and differential attack.

  12. The Encryption Export Policy Controversy: Searching for Balance in the Information Age

    National Research Council Canada - National Science Library

    Miller, Marcus S

    2000-01-01

    .... The federal government s encryption export policy highlights a complex information age issue involving seemingly insurmountable conflicts between national security, law enforcement, privacy, and business interests...

  13. Chocolate spot of Eucalyptus

    OpenAIRE

    Cheewangkoon, R.; Groenewald, J.Z.; Hyde, K.D.; To-anun, C.; Crous, P.W.

    2012-01-01

    Chocolate Spot leaf disease of Eucalyptus is associated with several Heteroconium-like species of hyphomycetes that resemble Heteroconium s.str. in morphology. They differ, however, in their ecology, with the former being plant pathogenic, while Heteroconium s.str. is a genus of sooty moulds. Results of molecular analyses, inferred from DNA sequences of the large subunit (LSU) and internal transcribed spacers (ITS) region of nrDNA, delineated four Heteroconium-like species on Eucalyptus, name...

  14. El spot electoral negativo

    Directory of Open Access Journals (Sweden)

    Palma Peña-Jiménez

    2011-01-01

    Full Text Available l spot político tiene durante la campaña un objetivo final inequívoco: la consecución del voto favorable. Se dirige al cuerpo electoral a través de la televisión y de Internet, y presenta, en muchos casos, un planteamiento negativo, albergando mensajes destinados a la crítica frontal contra el adversario, más que a la exposición de propuestas propias. Este artículo se centra en el análisis del spot electoral negativo, en aquellas producciones audiovisuales construidas sin más causa que la reprobación del contrincante. Se trata de vídeos que, lejos de emplearse en difundir las potencialidades de la organización y las virtudes de su candidato –además de su programa electoral–, consumen su tiempo en descalificar al oponente mediante la transmisión de mensajes, muchas veces, ad hominem. Repasamos el planteamiento negativo del spot electoral desde su primera manifestación, que en España data de 1996, año de emisión del conocido como vídeo del dóberman, sin olvidar otros ejemplos que completan el objeto de estudio.

  15. A novel image encryption algorithm based on a 3D chaotic map

    Science.gov (United States)

    Kanso, A.; Ghebleh, M.

    2012-07-01

    Recently [Solak E, Çokal C, Yildiz OT Biyikoǧlu T. Cryptanalysis of Fridrich's chaotic image encryption. Int J Bifur Chaos 2010;20:1405-1413] cryptanalyzed the chaotic image encryption algorithm of [Fridrich J. Symmetric ciphers based on two-dimensional chaotic maps. Int J Bifur Chaos 1998;8(6):1259-1284], which was considered a benchmark for measuring security of many image encryption algorithms. This attack can also be applied to other encryption algorithms that have a structure similar to Fridrich's algorithm, such as that of [Chen G, Mao Y, Chui, C. A symmetric image encryption scheme based on 3D chaotic cat maps. Chaos Soliton Fract 2004;21:749-761]. In this paper, we suggest a novel image encryption algorithm based on a three dimensional (3D) chaotic map that can defeat the aforementioned attack among other existing attacks. The design of the proposed algorithm is simple and efficient, and based on three phases which provide the necessary properties for a secure image encryption algorithm including the confusion and diffusion properties. In phase I, the image pixels are shuffled according to a search rule based on the 3D chaotic map. In phases II and III, 3D chaotic maps are used to scramble shuffled pixels through mixing and masking rules, respectively. Simulation results show that the suggested algorithm satisfies the required performance tests such as high level security, large key space and acceptable encryption speed. These characteristics make it a suitable candidate for use in cryptographic applications.

  16. The application of data encryption technology in computer network communication security

    Science.gov (United States)

    Gong, Lina; Zhang, Li; Zhang, Wei; Li, Xuhong; Wang, Xia; Pan, Wenwen

    2017-04-01

    With the rapid development of Intemet and the extensive application of computer technology, the security of information becomes more and more serious, and the information security technology with data encryption technology as the core has also been developed greatly. Data encryption technology not only can encrypt and decrypt data, but also can realize digital signature, authentication and authentication and other functions, thus ensuring the confidentiality, integrity and confirmation of data transmission over the network. In order to improve the security of data in network communication, in this paper, a hybrid encryption system is used to encrypt and decrypt the triple DES algorithm with high security, and the two keys are encrypted with RSA algorithm, thus ensuring the security of the triple DES key and solving the problem of key management; At the same time to realize digital signature using Java security software, to ensure data integrity and non-repudiation. Finally, the data encryption system is developed by Java language. The data encryption system is simple and effective, with good security and practicality.

  17. Processing in the encrypted domain using a composite signal representation : Pros and cons

    NARCIS (Netherlands)

    Bianchi, T.; Veugen, P.J.M.; Piva, A.; Barni, M.

    2009-01-01

    The current solutions for secure processing in the encrypted domain are usually based on homomorphic cryptosystems operating on very large algebraic structures. Recently, a composite signal representation has been proposed that allows to speed up linear operations on encrypted signals via parallel

  18. An Efficient Secret Key Homomorphic Encryption Used in Image Processing Service

    Directory of Open Access Journals (Sweden)

    Pan Yang

    2017-01-01

    Full Text Available Homomorphic encryption can protect user’s privacy when operating on user’s data in cloud computing. But it is not practical for wide using as the data and services types in cloud computing are diverse. Among these data types, digital image is an important personal data for users. There are also many image processing services in cloud computing. To protect user’s privacy in these services, this paper proposed a scheme using homomorphic encryption in image processing. Firstly, a secret key homomorphic encryption (IGHE was constructed for encrypting image. IGHE can operate on encrypted floating numbers efficiently to adapt to the image processing service. Then, by translating the traditional image processing methods into the operations on encrypted pixels, the encrypted image can be processed homomorphically. That is, service can process the encrypted image directly, and the result after decryption is the same as processing the plain image. To illustrate our scheme, three common image processing instances were given in this paper. The experiments show that our scheme is secure, correct, and efficient enough to be used in practical image processing applications.

  19. An Anti-Cheating Visual Cryptography Scheme Based on Chaotic Encryption System

    Science.gov (United States)

    Han, Yanyan; Xu, Zhuolin; Ge, Xiaonan; He, Wencai

    By chaotic encryption system and introducing the trusted third party (TTP), in this paper, an anti-cheating visual cryptography scheme (VCS) is proposed. The scheme solved the problem of dishonest participants and improved the security of chaotic encryption system. Simulation results and analysis show that the recovery image is acceptable, the system can detect the cheating in participants effectively and with high security.

  20. Single-intensity-recording optical encryption technique based on phase retrieval algorithm and QR code

    Science.gov (United States)

    Wang, Zhi-peng; Zhang, Shuai; Liu, Hong-zhao; Qin, Yi

    2014-12-01

    Based on phase retrieval algorithm and QR code, a new optical encryption technology that only needs to record one intensity distribution is proposed. In this encryption process, firstly, the QR code is generated from the information to be encrypted; and then the generated QR code is placed in the input plane of 4-f system to have a double random phase encryption. For only one intensity distribution in the output plane is recorded as the ciphertext, the encryption process is greatly simplified. In the decryption process, the corresponding QR code is retrieved using phase retrieval algorithm. A priori information about QR code is used as support constraint in the input plane, which helps solve the stagnation problem. The original information can be recovered without distortion by scanning the QR code. The encryption process can be implemented either optically or digitally, and the decryption process uses digital method. In addition, the security of the proposed optical encryption technology is analyzed. Theoretical analysis and computer simulations show that this optical encryption system is invulnerable to various attacks, and suitable for harsh transmission conditions.

  1. Tales from the crypt : Fingerprinting attacks on encrypted channels by way of retainting

    NARCIS (Netherlands)

    Valkering, Michael; Slowinska, Asia; Bos, Herbert

    2009-01-01

    Paradoxically, encryption makes it hard to detect, fingerprint and stop exploits. We describe Hassle, a honeypot capable of detecting and fingerprinting monomorphic and polymorphic attacks on encrypted channels. It uses dynamic taint analysis in an emulator to detect attacks, and it tags each

  2. Encrypted Davies-Meyer and its dual: Towards optimal security using mirror theory

    NARCIS (Netherlands)

    B. Mennink (Bart); S. Neves (Samuel)

    2017-01-01

    textabstractAt CRYPTO 2016, Cogliati and Seurin introduced the Encrypted Davies-Meyer construction, p2(p1(x)⊕x) for two n-bit permutations p1,p2, and proved security up to 22n/3. We present an improved security analysis up to 2n/(67n). Additionally, we introduce the dual of the Encrypted

  3. The Spotting Distribution of Wildfires

    Directory of Open Access Journals (Sweden)

    Jonathan Martin

    2016-06-01

    Full Text Available In wildfire science, spotting refers to non-local creation of new fires, due to downwind ignition of brands launched from a primary fire. Spotting is often mentioned as being one of the most difficult problems for wildfire management, because of its unpredictable nature. Since spotting is a stochastic process, it makes sense to talk about a probability distribution for spotting, which we call the spotting distribution. Given a location ahead of the fire front, we would like to know how likely is it to observe a spot fire at that location in the next few minutes. The aim of this paper is to introduce a detailed procedure to find the spotting distribution. Most prior modelling has focused on the maximum spotting distance, or on physical subprocesses. We will use mathematical modelling, which is based on detailed physical processes, to derive a spotting distribution. We discuss the use and measurement of this spotting distribution in fire spread, fire management and fire breaching. The appendix of this paper contains a comprehensive review of the relevant underlying physical sub-processes of fire plumes, launching fire brands, wind transport, falling and terminal velocity, combustion during transport, and ignition upon landing.

  4. Classification of Parking Spots Using Multilayer Perceptron Networks

    Directory of Open Access Journals (Sweden)

    FALCAO, H. S.

    2013-12-01

    Full Text Available This project intends to develop a prototype for the identification of free spots in open air parking area where there is a good aerial view without obstacles, allowing for the identification of occupied and free spots. We used image processing techniques and pattern recognition using Artificial Neural Networks (ANN. In order to help implement the prototype, we used Matlab. In order to simulate the parking area, we created a model so that we could acquire the images using a webcam, process them, train the neural network, classify the spots and finally, show the results. The results show that it is viable to apply pattern recognition through image capture to classify parking spots

  5. A chaos-based image encryption algorithm with variable control parameters

    International Nuclear Information System (INIS)

    Wang Yong; Wong, K.-W.; Liao Xiaofeng; Xiang Tao; Chen Guanrong

    2009-01-01

    In recent years, a number of image encryption algorithms based on the permutation-diffusion structure have been proposed. However, the control parameters used in the permutation stage are usually fixed in the whole encryption process, which favors attacks. In this paper, a chaos-based image encryption algorithm with variable control parameters is proposed. The control parameters used in the permutation stage and the keystream employed in the diffusion stage are generated from two chaotic maps related to the plain-image. As a result, the algorithm can effectively resist all known attacks against permutation-diffusion architectures. Theoretical analyses and computer simulations both confirm that the new algorithm possesses high security and fast encryption speed for practical image encryption.

  6. Implementation of digital image encryption algorithm using logistic function and DNA encoding

    Science.gov (United States)

    Suryadi, MT; Satria, Yudi; Fauzi, Muhammad

    2018-03-01

    Cryptography is a method to secure information that might be in form of digital image. Based on past research, in order to increase security level of chaos based encryption algorithm and DNA based encryption algorithm, encryption algorithm using logistic function and DNA encoding was proposed. Digital image encryption algorithm using logistic function and DNA encoding use DNA encoding to scramble the pixel values into DNA base and scramble it in DNA addition, DNA complement, and XOR operation. The logistic function in this algorithm used as random number generator needed in DNA complement and XOR operation. The result of the test show that the PSNR values of cipher images are 7.98-7.99 bits, the entropy values are close to 8, the histogram of cipher images are uniformly distributed and the correlation coefficient of cipher images are near 0. Thus, the cipher image can be decrypted perfectly and the encryption algorithm has good resistance to entropy attack and statistical attack.

  7. A novel color image encryption scheme using fractional-order hyperchaotic system and DNA sequence operations

    International Nuclear Information System (INIS)

    Zhang Li-Min; Sun Ke-Hui; Liu Wen-Hao; He Shao-Bo

    2017-01-01

    In this paper, Adomian decomposition method (ADM) with high accuracy and fast convergence is introduced to solve the fractional-order piecewise-linear (PWL) hyperchaotic system. Based on the obtained hyperchaotic sequences, a novel color image encryption algorithm is proposed by employing a hybrid model of bidirectional circular permutation and DNA masking. In this scheme, the pixel positions of image are scrambled by circular permutation, and the pixel values are substituted by DNA sequence operations. In the DNA sequence operations, addition and substraction operations are performed according to traditional addition and subtraction in the binary, and two rounds of addition rules are used to encrypt the pixel values. The simulation results and security analysis show that the hyperchaotic map is suitable for image encryption, and the proposed encryption algorithm has good encryption effect and strong key sensitivity. It can resist brute-force attack, statistical attack, differential attack, known-plaintext, and chosen-plaintext attacks. (paper)

  8. A novel hybrid color image encryption algorithm using two complex chaotic systems

    Science.gov (United States)

    Wang, Leyuan; Song, Hongjun; Liu, Ping

    2016-02-01

    Based on complex Chen and complex Lorenz systems, a novel color image encryption algorithm is proposed. The larger chaotic ranges and more complex behaviors of complex chaotic systems, which compared with real chaotic systems could additionally enhance the security and enlarge key space of color image encryption. The encryption algorithm is comprised of three step processes. In the permutation process, the pixels of plain image are scrambled via two-dimensional and one-dimensional permutation processes among RGB channels individually. In the diffusion process, the exclusive-or (XOR for short) operation is employed to conceal pixels information. Finally, the mixing RGB channels are used to achieve a multilevel encryption. The security analysis and experimental simulations demonstrate that the proposed algorithm is large enough to resist the brute-force attack and has excellent encryption performance.

  9. Modified computational integral imaging-based double image encryption using fractional Fourier transform

    Science.gov (United States)

    Li, Xiao-Wei; Lee, In-Kwon

    2015-03-01

    In this paper, we propose an image encryption technique to simultaneously encrypt double or multiple images into one encrypted image using computational integral imaging (CII) and fractional Fourier transform (FrFT). In the encryption, each of the input plane images are located at different positions along a pickup plane, and simultaneously recorded in the form of an elemental image array (EIA) through a lenslet array. The recorded EIA to be encrypted is multiplied by FrFT with two different fractional orders. In order to mitigate the drawbacks of occlusion noise in computational integral imaging reconstruction (CIIR), the plane images can be reconstructed using a modified CIIR technique. To further improve the solution of the reconstructed plane images, a block matching algorithm is also introduced. Numerical simulation results verify the feasibility and effectiveness of the proposed method.

  10. Key Management Strategies for Safeguards Authentication and Encryption

    International Nuclear Information System (INIS)

    Coram, M.; Hymel, R.; McDaniel, M.; Brotz, J.

    2015-01-01

    Management of cryptographic keys for the authentication and encryption of safeguards data can be the critical weak link in the practical implementation of information security. Within the safeguards community, there is the need to validate that data has not been modified at any point since generation and that it was generated by the monitoring node and not an imposter. In addition, there is the need for that data to be transmitted securely between the monitoring node and the monitoring party such that it cannot be intercepted and read while in transit. Encryption and digital signatures support the required confidentiality and authenticity but challenges exist in managing the cryptographic keys they require. Technologies developed at Sandia National Laboratories have evolved in their use of an associated key management strategy. The first generation system utilized a shared secret key for digital signatures. While fast and efficient, it required that a list of keys be maintained and protected. If control of the key was lost, fraudulent data could be made to look authentic. The second generation changed to support public key / private key cryptography. The key pair is generated by the system, the public key shared, and the private key held internally. This approach eliminated the need to maintain the list of keys. It also allows the public key to be provided to anyone needing to authenticate the data without allowing them to spoof data. A third generation system, currently under development, improves upon the public key / private key approach to address a potential man-in-the-middle attack related to the sharing of the public key. In a planned fourth generation system, secure key exchange protocols will distribute session keys for encryption, eliminating another fixed set of keys utilized by the technology and allowing for periodic renegotiation of keys for enhanced security. (author)

  11. Proof of cipher text ownership based on convergence encryption

    Science.gov (United States)

    Zhong, Weiwei; Liu, Zhusong

    2017-08-01

    Cloud storage systems save disk space and bandwidth through deduplication technology, but with the use of this technology has been targeted security attacks: the attacker can get the original file just use hash value to deceive the server to obtain the file ownership. In order to solve the above security problems and the different security requirements of cloud storage system files, an efficient information theory security proof of ownership scheme is proposed. This scheme protects the data through the convergence encryption method, and uses the improved block-level proof of ownership scheme, and can carry out block-level client deduplication to achieve efficient and secure cloud storage deduplication scheme.

  12. How to Securely Release Unverified Plaintext in Authenticated Encryption

    DEFF Research Database (Denmark)

    Andreeva, Elena; Bogdanov, Andrey; Luykx, Atul

    2014-01-01

    Scenarios in which authenticated encryption schemes output decrypted plaintext before successful verification raise many security issues. These situations are sometimes unavoidable in practice, such as when devices have insufficient memory to store an entire plaintext, or when a decrypted plaintext...... in the symmetric-key setting, PA1 and PA2, and show that they expose a new layer of security between IND-CPA and IND-CCA. To achieve integrity, INT-CTXT in the RUP setting is required, which we refer to as INT-RUP. These new security notions are compared with conventional definitions, and are used to make...

  13. Game of Drones - Detecting Streamed POI from Encrypted FPV Channel

    OpenAIRE

    Nassi, Ben; Ben-Netanel, Raz; Shamir, Adi; Elovici, Yuval

    2018-01-01

    Drones have created a new threat to people's privacy. We are now in an era in which anyone with a drone equipped with a video camera can use it to invade a subject's privacy by streaming the subject in his/her private space over an encrypted first person view (FPV) channel. Although many methods have been suggested to detect nearby drones, they all suffer from the same shortcoming: they cannot identify exactly what is being captured, and therefore they fail to distinguish between the legitima...

  14. Asymmetric Image Encryption Approach with Plaintext-Related Diffusion

    Directory of Open Access Journals (Sweden)

    J. Oravec

    2018-04-01

    Full Text Available This paper deals with topic of image encryption based on chaotic maps. A solution which has advantage of robustness against chosen-plaintext attacks is proposed. Permutations of image pixels are carried out in a way that enables operations on grayscale images with arbitrary resolution. All calculations done with user key and also all diffusion processes employ the same chaotic map. This feature enables usage of look-up tables which reduce computational times. The paper includes several experiments which verify achieved results and also briefly describes advantages and drawbacks of proposed solution.

  15. The LOCAL attack: Cryptanalysis of the authenticated encryption scheme ALE

    DEFF Research Database (Denmark)

    Khovratovich, Dmitry; Rechberger, Christian

    2014-01-01

    We show how to produce a forged (ciphertext, tag) pair for the scheme ALE with data and time complexity of 2102 ALE encryptions of short messages and the same number of authentication attempts. We use a differential attack based on a local collision, which exploits the availability of extracted...... state bytes to the adversary. Our approach allows for a time-data complexity tradeoff, with an extreme case of a forgery produced after 2119 attempts and based on a single authenticated message. Our attack is further turned into a state recovery and a universal forgery attack with a time complexity...

  16. DNA-nanostructure-assembly by sequential spotting

    Directory of Open Access Journals (Sweden)

    Breitenstein Michael

    2011-11-01

    Full Text Available Abstract Background The ability to create nanostructures with biomolecules is one of the key elements in nanobiotechnology. One of the problems is the expensive and mostly custom made equipment which is needed for their development. We intended to reduce material costs and aimed at miniaturization of the necessary tools that are essential for nanofabrication. Thus we combined the capabilities of molecular ink lithography with DNA-self-assembling capabilities to arrange DNA in an independent array which allows addressing molecules in nanoscale dimensions. Results For the construction of DNA based nanostructures a method is presented that allows an arrangement of DNA strands in such a way that they can form a grid that only depends on the spotted pattern of the anchor molecules. An atomic force microscope (AFM has been used for molecular ink lithography to generate small spots. The sequential spotting process allows the immobilization of several different functional biomolecules with a single AFM-tip. This grid which delivers specific addresses for the prepared DNA-strand serves as a two-dimensional anchor to arrange the sequence according to the pattern. Once the DNA-nanoarray has been formed, it can be functionalized by PNA (peptide nucleic acid to incorporate advanced structures. Conclusions The production of DNA-nanoarrays is a promising task for nanobiotechnology. The described method allows convenient and low cost preparation of nanoarrays. PNA can be used for complex functionalization purposes as well as a structural element.

  17. Meteorology of Jupiter's Equatorial Hot Spots and Plumes from Cassini

    Science.gov (United States)

    Choi, David Sanghun; Showman, Adam P.; Vasavada, Ashwin R.; Simon-Miller, Amy A.

    2013-01-01

    We present an updated analysis of Jupiter's equatorial meteorology from Cassini observations. For two months preceding the spacecraft's closest approach, the Imaging Science Subsystem (ISS) onboard regularly imaged the atmosphere. We created time-lapse movies from this period in order to analyze the dynamics of equatorial hot spots and their interactions with adjacent latitudes. Hot spots are relatively cloud-free regions that emit strongly at 5 lm; improved knowledge of these features is crucial for fully understanding Galileo probe measurements taken during its descent through one. Hot spots are quasistable, rectangular dark areas on visible-wavelength images, with defined eastern edges that sharply contrast with surrounding clouds, but diffuse western edges serving as nebulous boundaries with adjacent equatorial plumes. Hot spots exhibit significant variations in size and shape over timescales of days and weeks. Some of these changes correspond with passing vortex systems from adjacent latitudes interacting with hot spots. Strong anticyclonic gyres present to the south and southeast of the dark areas appear to circulate into hot spots. Impressive, bright white plumes occupy spaces in between hot spots. Compact cirrus-like 'scooter' clouds flow rapidly through the plumes before disappearing within the dark areas. These clouds travel at 150-200 m/s, much faster than the 100 m/s hot spot and plume drift speed. This raises the possibility that the scooter clouds may be more illustrative of the actual jet stream speed at these latitudes. Most previously published zonal wind profiles represent the drift speed of the hot spots at their latitude from pattern matching of the entire longitudinal image strip. If a downward branch of an equatorially-trapped Rossby wave controls the overall appearance of hot spots, however, the westward phase velocity of the wave leads to underestimates of the true jet stream speed.

  18. A new optical encryption system for image transformation

    Science.gov (United States)

    Yao, Shuyu; Chen, Linfei; Chang, Guojun; He, Bingyu

    2017-12-01

    This paper introduces a new optical image encryption system based on Fresnel diffraction and phase iterative algorithm, which can realize the conversion between different images. The method is based on the optical system of free space transmission, and uses the iterative phase retrieval algorithm to encode an image into two phase masks and a ciphertext. Unlike the existed methods, the ciphertext is a visible image, which can be used to achieve the conversion of one image to another image. In order to enhance the security, two phase masks are combined into a wide-scale phase mask by the double image cross pixel scrambling approach. In the decryption process, the wide-scale phase mask is re-decrypted into two random phase masks using a random shift matrix. The ciphertext and the first phase mask are placed on the input plane and the second random phase mask is placed on the transformation plane. The Fresnel diffraction principle can be used to obtain the plaintext information on the output plane. Theoretical analysis and simulation results show that the encryption system is feasible and quite safe.

  19. Optical image encryption in Fresnel domain using spiral phase transform

    Science.gov (United States)

    Kumar, Ravi; Bhaduri, Basanta

    2017-09-01

    In this study, we propose a new nonlinear optical image encryption technique using spiral phase transform (SPT). First, the primary image is phase encoded and multiplied with a random amplitude mask (RAM), and using power function, the product is then powered to m. This powered output is Fresnel propagated with distance z 1 and then modulated with a random phase mask (RPM). The modulated image is further Fresnel propagated with distance z 2. Similarly, a security image is also modulated with another RAM and then Fresnel propagated with distance z 3. Next, the two modulated images after Fresnel propagations, are interfered and further Fresnel propagated with distance z 4 to get a complex image. Finally, this complex image is SPT with particular spiral phase function (SPF), to get the final encrypted image for transmission. In the proposed technique, the security keys are Fresnel propagation distances, the security image, RPM, RAMs, power order, m, and order of SPF, q. Numerical simulation results confirm the validity and effectiveness of the proposed technique. The proposed technique is robust against noise and brutal force attacks.

  20. Encryption and validation of multiple signals for optical identification systems

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Cabre, E [Universitat PoliteGcnica de Catalunya, Department Optica i Optometria, Violinista Vellsola 37, 08222 Terrassa (Spain); Millan, M S [Universitat PoliteGcnica de Catalunya, Department Optica i Optometria, Violinista Vellsola 37, 08222 Terrassa (Spain); Javidi, B [University of Connecticut, Electrical and Computer Engineering Department, 371 Fairfield Road, CT 06269 Storrs (United States)

    2007-07-15

    Multifactor encryption-authentication technique reinforces optical security by allowing the simultaneous A N D-verification of more than one primary image. Instead of basing the identification on a unique signature or piece of information, our goal is to authenticate a given person, object, vehicle by the simultaneous recognition of several factors. Some of them are intrinsic to the person and object or vehicle under control. Other factors, act as keys of the authentication step. Such a system is proposed for situations such as the access control to restricted areas, where the demand of security is high. The multifactor identification method involves double random-phase encoding, fully phase-based encryption and a combined nonlinear joint transform correlator and a classical 4f-correlator for simultaneous recognition and authentication of multiple images. The encoded signal fulfils the general requirements of invisible content, extreme difficulty in counterfeiting and real-time automatic verification. Four reference double-phase encoded images are compared with the retrieved input images obtained in situ from the person or the vehicle whose authentication is wanted and from a database. A recognition step based on the correlation between the signatures and the stored references determines the authentication or rejection of the person and object under surveillance.

  1. Secure Image Steganography Algorithm Based on DCT with OTP Encryption

    Directory of Open Access Journals (Sweden)

    De Rosal Ignatius Moses Setiadi

    2017-04-01

    Full Text Available Rapid development of Internet makes transactions message even easier and faster. The main problem in the transactions message is security, especially if the message is private and secret. To secure these messages is usually done with steganography or cryptography. Steganography is a way to hide messages into other digital content such as images, video or audio so it does not seem nondescript from the outside. While cryptography is a technique to encrypt messages so that messages can not be read directly. In this paper have proposed combination of steganography using discrete cosine transform (DCT and cryptography using the one-time pad or vernam cipher implemented on a digital image. The measurement method used to determine the quality of stego image is the peak signal to noise ratio (PSNR and ormalize cross Correlation (NCC to measure the quality of the extraction of the decrypted message. Of steganography and encryption methods proposed obtained satisfactory results with PSNR and NCC high and resistant to JPEG compression and median filter. Keywords—Image Steganography, Discrete Cosine Transform (DCT, One Time Pad, Vernam, Chiper, Image Cryptography

  2. Cryptographic analysis on the key space of optical phase encryption algorithm based on the design of discrete random phase mask

    Science.gov (United States)

    Lin, Chao; Shen, Xueju; Li, Zengyan

    2013-07-01

    The key space of phase encryption algorithm using discrete random phase mask is investigated by numerical simulation in this paper. Random phase mask with finite and discrete phase levels is considered as the core component in most practical optical encryption architectures. The key space analysis is based on the design criteria of discrete random phase mask. The role of random amplitude mask and random phase mask in optical encryption system is identified from the perspective of confusion and diffusion. The properties of discrete random phase mask in a practical double random phase encoding scheme working in both amplitude encoding (AE) and phase encoding (PE) modes are comparably analyzed. The key space of random phase encryption algorithm is evaluated considering both the encryption quality and the brute-force attack resistibility. A method for enlarging the key space of phase encryption algorithm is also proposed to enhance the security of optical phase encryption techniques.

  3. Complementary Metal-Oxide-Silicon (CMOS)-Memristor Hybrid Nanoelectronics for Advanced Encryption Standard (AES) Encryption

    Science.gov (United States)

    2016-04-01

    electrodes (TEs) for the development study were patterned using either a shadow mask or a conventional photolithography-based lift-off process. Au...organic precursor, and a 300 W RF O2 plasma as the reactant. The target thickness of HfOx was 50 nm, which required 603 ALD cycles, totaling 6.23...TEs were patterned using either a shadow mask or a conventional photolithography-based lift-off process. Au, Ni, Al, or Pt were deposited

  4. The Development of a Portable Hard Disk Encryption/Decryption System with a MEMS Coded Lock.

    Science.gov (United States)

    Zhang, Weiping; Chen, Wenyuan; Tang, Jian; Xu, Peng; Li, Yibin; Li, Shengyong

    2009-01-01

    In this paper, a novel portable hard-disk encryption/decryption system with a MEMS coded lock is presented, which can authenticate the user and provide the key for the AES encryption/decryption module. The portable hard-disk encryption/decryption system is composed of the authentication module, the USB portable hard-disk interface card, the ATA protocol command decoder module, the data encryption/decryption module, the cipher key management module, the MEMS coded lock controlling circuit module, the MEMS coded lock and the hard disk. The ATA protocol circuit, the MEMS control circuit and AES encryption/decryption circuit are designed and realized by FPGA(Field Programmable Gate Array). The MEMS coded lock with two couplers and two groups of counter-meshing-gears (CMGs) are fabricated by a LIGA-like process and precision engineering method. The whole prototype was fabricated and tested. The test results show that the user's password could be correctly discriminated by the MEMS coded lock, and the AES encryption module could get the key from the MEMS coded lock. Moreover, the data in the hard-disk could be encrypted or decrypted, and the read-write speed of the dataflow could reach 17 MB/s in Ultra DMA mode.

  5. Suggested Method for Encryption and Hiding ‎Image using LCG and LSB

    Directory of Open Access Journals (Sweden)

    Atheer Hussein Zyara

    2017-12-01

    Full Text Available Maintaining the confidentiality of the data of the very important areas in computer applications , Where many researchers work in the fields of concealment and encryption . So in this research we are working on the combining of the two methods , where confidential data is encrypted by using  a proposed method , Then the cover is encrypted (regular image by LCG algorithm (which generates a series of random numbers to generate the encrypted cover (irregular image , After that ,we hide the encrypted data in encrypted cover by depending on the LSB technique, then we convert the irregular image into regular image and thereby getting  hidden data in random locations in the  cover image  , This method is characterized by flexibility in terms of the possibility of hiding the different  types of confidential data in different types of media , and durability as that data be hidden in random locations and this  what distinguishes the proposed algorithm , and the results showed high security, because the data is hidden in random locations in encrypted image then convert to the original regular image For clarification of the proposed algorithm , it has been applied on a digital image of the gray type using MATLAB language  by using the efficiency scales PSNR and MSE

  6. A Symmetric Plaintext-Related Color Image Encryption System Based on Bit Permutation

    Directory of Open Access Journals (Sweden)

    Shuting Cai

    2018-04-01

    Full Text Available Recently, a variety of chaos-based image encryption algorithms adopting the traditional permutation-diffusion structure have been suggested. Most of these algorithms cannot resist the powerful chosen-plaintext attack and chosen-ciphertext attack efficiently for less sensitivity to plain-image. This paper presents a symmetric color image encryption system based on plaintext-related random access bit-permutation mechanism (PRRABPM. In the proposed scheme, a new random access bit-permutation mechanism is used to shuffle 3D bit matrix transformed from an original color image, making the RGB components of the color image interact with each other. Furthermore, the key streams used in random access bit-permutation mechanism operation are extremely dependent on plain image in an ingenious way. Therefore, the encryption system is sensitive to tiny differences in key and original images, which means that it can efficiently resist chosen-plaintext attack and chosen-ciphertext attack. In the diffusion stage, the previous encrypted pixel is used to encrypt the current pixel. The simulation results show that even though the permutation-diffusion operation in our encryption scheme is performed only one time, the proposed algorithm has favorable security performance. Considering real-time applications, the encryption speed can be further improved.

  7. Multi-agent integrated password management (MIPM) application secured with encryption

    Science.gov (United States)

    Awang, Norkhushaini; Zukri, Nurul Hidayah Ahmad; Rashid, Nor Aimuni Md; Zulkifli, Zuhri Arafah; Nazri, Nor Afifah Mohd

    2017-10-01

    Users use weak passwords and reuse them on different websites and applications. Password managers are a solution to store login information for websites and help users log in automatically. This project developed a system that acts as an agent managing passwords. Multi-Agent Integrated Password Management (MIPM) is an application using encryption that provides users with secure storage of their login account information such as their username, emails and passwords. This project was developed on an Android platform with an encryption agent using Java Agent Development Environment (JADE). The purpose of the embedded agents is to act as a third-party software to ease the encryption process, and in the future, the developed encryption agents can form part of the security system. This application can be used by the computer and mobile users. Currently, users log into many applications causing them to use unique passwords to prevent password leaking. The crypto agent handles the encryption process using an Advanced Encryption Standard (AES) 128-bit encryption algorithm. As a whole, MIPM is developed on the Android application to provide a secure platform to store passwords and has high potential to be commercialised for public use.

  8. Iteration and superposition encryption scheme for image sequences based on multi-dimensional keys

    Science.gov (United States)

    Han, Chao; Shen, Yuzhen; Ma, Wenlin

    2017-12-01

    An iteration and superposition encryption scheme for image sequences based on multi-dimensional keys is proposed for high security, big capacity and low noise information transmission. Multiple images to be encrypted are transformed into phase-only images with the iterative algorithm and then are encrypted by different random phase, respectively. The encrypted phase-only images are performed by inverse Fourier transform, respectively, thus new object functions are generated. The new functions are located in different blocks and padded zero for a sparse distribution, then they propagate to a specific region at different distances by angular spectrum diffraction, respectively and are superposed in order to form a single image. The single image is multiplied with a random phase in the frequency domain and then the phase part of the frequency spectrums is truncated and the amplitude information is reserved. The random phase, propagation distances, truncated phase information in frequency domain are employed as multiple dimensional keys. The iteration processing and sparse distribution greatly reduce the crosstalk among the multiple encryption images. The superposition of image sequences greatly improves the capacity of encrypted information. Several numerical experiments based on a designed optical system demonstrate that the proposed scheme can enhance encrypted information capacity and make image transmission at a highly desired security level.

  9. Context adaptive binary arithmetic coding-based data hiding in partially encrypted H.264/AVC videos

    Science.gov (United States)

    Xu, Dawen; Wang, Rangding

    2015-05-01

    A scheme of data hiding directly in a partially encrypted version of H.264/AVC videos is proposed which includes three parts, i.e., selective encryption, data embedding and data extraction. Selective encryption is performed on context adaptive binary arithmetic coding (CABAC) bin-strings via stream ciphers. By careful selection of CABAC entropy coder syntax elements for selective encryption, the encrypted bitstream is format-compliant and has exactly the same bit rate. Then a data-hider embeds the additional data into partially encrypted H.264/AVC videos using a CABAC bin-string substitution technique without accessing the plaintext of the video content. Since bin-string substitution is carried out on those residual coefficients with approximately the same magnitude, the quality of the decrypted video is satisfactory. Video file size is strictly preserved even after data embedding. In order to adapt to different application scenarios, data extraction can be done either in the encrypted domain or in the decrypted domain. Experimental results have demonstrated the feasibility and efficiency of the proposed scheme.

  10. Advances in spot curing technology

    International Nuclear Information System (INIS)

    Burga, R.

    1999-01-01

    A brief review of spot curing technology was presented. The process which a spot of energy of a specific wavelength bandwidth and irradiance is used to cause a coating, encapsulant or adhesive to change from a liquid to a solid state

  11. [Formula: see text]: Oblivious similarity based searching for encrypted data outsourced to an untrusted domain.

    Science.gov (United States)

    Pervez, Zeeshan; Ahmad, Mahmood; Khattak, Asad Masood; Ramzan, Naeem; Khan, Wajahat Ali

    2017-01-01

    Public cloud storage services are becoming prevalent and myriad data sharing, archiving and collaborative services have emerged which harness the pay-as-you-go business model of public cloud. To ensure privacy and confidentiality often encrypted data is outsourced to such services, which further complicates the process of accessing relevant data by using search queries. Search over encrypted data schemes solve this problem by exploiting cryptographic primitives and secure indexing to identify outsourced data that satisfy the search criteria. Almost all of these schemes rely on exact matching between the encrypted data and search criteria. A few schemes which extend the notion of exact matching to similarity based search, lack realism as those schemes rely on trusted third parties or due to increase storage and computational complexity. In this paper we propose Oblivious Similarity based Search ([Formula: see text]) for encrypted data. It enables authorized users to model their own encrypted search queries which are resilient to typographical errors. Unlike conventional methodologies, [Formula: see text] ranks the search results by using similarity measure offering a better search experience than exact matching. It utilizes encrypted bloom filter and probabilistic homomorphic encryption to enable authorized users to access relevant data without revealing results of search query evaluation process to the untrusted cloud service provider. Encrypted bloom filter based search enables [Formula: see text] to reduce search space to potentially relevant encrypted data avoiding unnecessary computation on public cloud. The efficacy of [Formula: see text] is evaluated on Google App Engine for various bloom filter lengths on different cloud configurations.

  12. Atomic-AES: A compact implementation of the AES encryption/decryption core

    DEFF Research Database (Denmark)

    Banik, Subhadeep; Bogdanov, Andrey; Regazzoni, Francesco

    2016-01-01

    The implementation of the AES encryption core by Moradi et al. at Eurocrypt 2011 is one of the smallest in terms of gate area. The circuit takes around 2400 gates and operates on an 8 bit datapath. However this is an encryption only core and unable to cater to block cipher modes like CBC and ELm...... report an 8-bit serialized AES circuit that provides the functionality of both encryption and decryption and occupies around 2645 GE with a latency of 226 cycles. This is a substantial improvement over the next smallest AES ENC/DEC circuit (Grain of Sand) by Feldhofer et al. which takes around 3400 gates...

  13. Optical encryption and QR codes: secure and noise-free information retrieval.

    Science.gov (United States)

    Barrera, John Fredy; Mira, Alejandro; Torroba, Roberto

    2013-03-11

    We introduce for the first time the concept of an information "container" before a standard optical encrypting procedure. The "container" selected is a QR code which offers the main advantage of being tolerant to pollutant speckle noise. Besides, the QR code can be read by smartphones, a massively used device. Additionally, QR code includes another secure step to the encrypting benefits the optical methods provide. The QR is generated by means of worldwide free available software. The concept development probes that speckle noise polluting the outcomes of normal optical encrypting procedures can be avoided, then making more attractive the adoption of these techniques. Actual smartphone collected results are shown to validate our proposal.

  14. New CA Based Image Encryption-Scaling Scheme Using Wavelet Transform

    Directory of Open Access Journals (Sweden)

    Bala Suyambu Jeyaram

    2014-06-01

    Full Text Available The wide use of digital images leads to the necessity of securing them when they enter into an insecure channel. Image cryptography plays a vital role in the modern communication. In this paper we propose a new image encryption scaling scheme, which will do both, image scaling and encryption. Cellular automata is used for key generation and wavelet transformation is used for image scaling. Encryption has been done in two steps: one before wavelet transformation and another one after the wavelet transformation. Performance evaluation results clearly show that the proposed method is better in all aspects.

  15. Exploiting chaos-based compressed sensing and cryptographic algorithm for image encryption and compression

    Science.gov (United States)

    Chen, Junxin; Zhang, Yu; Qi, Lin; Fu, Chong; Xu, Lisheng

    2018-02-01

    This paper presents a solution for simultaneous image encryption and compression. The primary introduced techniques are compressed sensing (CS) using structurally random matrix (SRM), and permutation-diffusion type image encryption. The encryption performance originates from both the techniques, whereas the compression effect is achieved by CS. Three-dimensional (3-D) cat map is employed for key stream generation. The simultaneously produced three state variables of 3-D cat map are respectively used for the SRM generation, image permutation and diffusion. Numerical simulations and security analyses have been carried out, and the results demonstrate the effectiveness and security performance of the proposed system.

  16. Color image encryption using random transforms, phase retrieval, chaotic maps, and diffusion

    Science.gov (United States)

    Annaby, M. H.; Rushdi, M. A.; Nehary, E. A.

    2018-04-01

    The recent tremendous proliferation of color imaging applications has been accompanied by growing research in data encryption to secure color images against adversary attacks. While recent color image encryption techniques perform reasonably well, they still exhibit vulnerabilities and deficiencies in terms of statistical security measures due to image data redundancy and inherent weaknesses. This paper proposes two encryption algorithms that largely treat these deficiencies and boost the security strength through novel integration of the random fractional Fourier transforms, phase retrieval algorithms, as well as chaotic scrambling and diffusion. We show through detailed experiments and statistical analysis that the proposed enhancements significantly improve security measures and immunity to attacks.

  17. Complete mitochondrial genome of the red-spotted tokay gecko (Gekko gecko, Reptilia: Gekkonidae): comparison of red- and black-spotted tokay geckos.

    Science.gov (United States)

    Qin, Xin-Min; Qian, Fang; Zeng, De-Long; Liu, Xiao-Can; Li, Hui-Min

    2011-10-01

    Here, we sequenced the complete mitochondrial genome of the red-spotted tokay gecko (Squamata: Gekkonidae). The genome is 16,590 bp in size. Its gene arrangement pattern was identical with that of black-spotted tokay gecko. We compared the mitochondrial genome of red-spotted tokay gecko with that of the black-spotted tokay gecko. Nucleotide sequence of the two whole mitochondrial genomes was 97.99% similar, and the relatively high similarity seems to indicate that they may be separated at the subspecies level. The information of mitochondrial genome comparison of the two morphological types of tokay gecko is discussed in detail.

  18. Continuous-variable quantum computing on encrypted data.

    Science.gov (United States)

    Marshall, Kevin; Jacobsen, Christian S; Schäfermeier, Clemens; Gehring, Tobias; Weedbrook, Christian; Andersen, Ulrik L

    2016-12-14

    The ability to perform computations on encrypted data is a powerful tool for protecting a client's privacy, especially in today's era of cloud and distributed computing. In terms of privacy, the best solutions that classical techniques can achieve are unfortunately not unconditionally secure in the sense that they are dependent on a hacker's computational power. Here we theoretically investigate, and experimentally demonstrate with Gaussian displacement and squeezing operations, a quantum solution that achieves the security of a user's privacy using the practical technology of continuous variables. We demonstrate losses of up to 10 km both ways between the client and the server and show that security can still be achieved. Our approach offers a number of practical benefits (from a quantum perspective) that could one day allow the potential widespread adoption of this quantum technology in future cloud-based computing networks.

  19. Authenticated Encryption for Low-Power Reconfigurable Wireless Devices

    DEFF Research Database (Denmark)

    Khajuria, Samant; Andersen, Birger

    2013-01-01

    this enabling technology, these radios have to propose cryptographic services such as con- fidentiality, integrity and authentication. Therefore, integration of security services to these low-power devices is very challenging and crucial as they have limited resources and computational capabilities......With the rapid growth of new wireless communication standards, a solution that is capable of providing a seamless shift between existing wireless protocols and high flexibility as well as capability is crucial. Technology based on reconfigurable devices offers this flexibility. In order to avail....... In this paper, we present a crypto solution for reconfigurable devices. The solution is a single pass Authenticated Encryption (AE) scheme that is designed for protecting both message confidentiality and its authenticity. This makes AE very attractive for low-cost low-power hardware implementation. For test...

  20. Lessons learned: mobile device encryption in the academic medical center.

    Science.gov (United States)

    Kusche, Kristopher P

    2009-01-01

    The academic medical center is faced with the unique challenge of meeting the multi-faceted needs of both a modern healthcare organization and an academic institution, The need for security to protect patient information must be balanced by the academic freedoms expected in the college setting. The Albany Medical Center, consisting of the Albany Medical College and the Albany Medical Center Hospital, was challenged with implementing a solution that would preserve the availability, integrity and confidentiality of business, patient and research data stored on mobile devices. To solve this problem, Albany Medical Center implemented a mobile encryption suite across the enterprise. Such an implementation comes with complexities, from performance across multiple generations of computers and operating systems, to diversity of application use mode and end user adoption, all of which requires thoughtful policy and standards creation, understanding of regulations, and a willingness and ability to work through such diverse needs.

  1. E-mail security: mail clients must use encrypted protocols

    CERN Multimedia

    2006-01-01

    In the coming weeks, users of mail clients other than Outlook (e.g. Pine, Mozilla, Mac Mail, etc.) may receive an e-mail from Mail-service@cern.ch with instructions to update the security settings of their mail client. The aim of this campaign is to enforce the use of encrypted and authenticated mail protocols in order to prevent the propagation of viruses and protect passwords from theft. As a first step, from 6 June 2006 onwards, access to mail servers from outside CERN will require a securely configured mail client as described in the help page http://cern.ch/mmmservices/Help/?kbid=191040. On this page most users will also find tools that will update their mail client settings automatically. Note that Outlook clients and WebMail access are not affected. The Mail Team

  2. Fault Attacks on the Authenticated Encryption Stream Cipher MORUS

    Directory of Open Access Journals (Sweden)

    Iftekhar Salam

    2018-01-01

    Full Text Available This paper investigates the application of fault attacks to the authenticated encryption stream cipher algorithm MORUS. We propose fault attacks on MORUS with two different goals: one to breach the confidentiality component, and the other to breach the integrity component. For the fault attack on the confidentiality component of MORUS, we propose two different types of key recovery. The first type is a partial key recovery using a permanent fault model, except for one of the variants of MORUS where the full key is recovered with this model. The second type is a full key recovery using a transient fault model, at the cost of a higher number of faults compared to the permanent fault model. Finally, we describe a fault attack on the integrity component of MORUS, which performs a forgery using the bit-flipping fault model.

  3. Continuous-variable quantum computing on encrypted data

    Science.gov (United States)

    Marshall, Kevin; Jacobsen, Christian S.; Schäfermeier, Clemens; Gehring, Tobias; Weedbrook, Christian; Andersen, Ulrik L.

    2016-12-01

    The ability to perform computations on encrypted data is a powerful tool for protecting a client's privacy, especially in today's era of cloud and distributed computing. In terms of privacy, the best solutions that classical techniques can achieve are unfortunately not unconditionally secure in the sense that they are dependent on a hacker's computational power. Here we theoretically investigate, and experimentally demonstrate with Gaussian displacement and squeezing operations, a quantum solution that achieves the security of a user's privacy using the practical technology of continuous variables. We demonstrate losses of up to 10 km both ways between the client and the server and show that security can still be achieved. Our approach offers a number of practical benefits (from a quantum perspective) that could one day allow the potential widespread adoption of this quantum technology in future cloud-based computing networks.

  4. RSA cryptosystem with fuzzy set theory for encryption and decryption

    Science.gov (United States)

    Abdullah, Kamilah; Bakar, Sumarni Abu; Kamis, Nor Hanimah; Aliamis, Hardi

    2017-11-01

    In the communication area, user is more focus on communication instead of security of the data communication. Many cryptosystems have been improvised to achieved the effectiveness in communication. RSA cryptosystem is one of well-known cryptosystem used to secure the information and protect the communication by providing a difficulty to the attackers specifically in encryption and decryption. As need arises for guarantee the security of the cryptosystem while the communication must be ensured, we propose a new RSA cryptosystem which is based on fuzzy set theory whereby the plaintext and the ciphertext are in terms of Triangular Fuzzy Number (TFN). Decryption result shows that the message obtained is the same as the original plaintext. This study reveals that the fuzzy set theory is suitable to be used as an alternative tool in securing other cryptosystem.

  5. A fast image encryption algorithm based on chaotic map

    Science.gov (United States)

    Liu, Wenhao; Sun, Kehui; Zhu, Congxu

    2016-09-01

    Derived from Sine map and iterative chaotic map with infinite collapse (ICMIC), a new two-dimensional Sine ICMIC modulation map (2D-SIMM) is proposed based on a close-loop modulation coupling (CMC) model, and its chaotic performance is analyzed by means of phase diagram, Lyapunov exponent spectrum and complexity. It shows that this map has good ergodicity, hyperchaotic behavior, large maximum Lyapunov exponent and high complexity. Based on this map, a fast image encryption algorithm is proposed. In this algorithm, the confusion and diffusion processes are combined for one stage. Chaotic shift transform (CST) is proposed to efficiently change the image pixel positions, and the row and column substitutions are applied to scramble the pixel values simultaneously. The simulation and analysis results show that this algorithm has high security, low time complexity, and the abilities of resisting statistical analysis, differential, brute-force, known-plaintext and chosen-plaintext attacks.

  6. An Ultra-Lightweight Encryption Scheme in Underwater Acoustic Networks

    Directory of Open Access Journals (Sweden)

    Chunyan Peng

    2016-01-01

    Full Text Available We tackle a fundamental security problem in underwater acoustic networks (UANs. The S-box in the existing block encryption algorithm is more energy consuming and unsuitable for resources-constrained UANs. In this paper, instead of S-box, we present a lightweight, 8-round iteration block cipher algorithm for UANs communication based on chaotic theory and increase the key space by changing the number of iteration round. We further propose secure network architecture of UANs. By analysis, our algorithm can resist brute-force searches and adversarial attacks. Simulation results show that, compared with traditional AES-128 and PRESENT algorithms, our cryptographic algorithm can make a good trade-off between security and overhead, has better energy efficiency, and applies to UANs.

  7. Synchronization properties of chaotic semiconductor lasers and applications to encryption

    Science.gov (United States)

    Mirasso, Claudio R.; Vicente, Raúl; Colet, Pere; Mulet, Josep; Pérez, Toni

    2004-08-01

    We review the main properties of two unidirectionally coupled single-mode semiconductor lasers ( master-slave configuration). Our analysis is based on numerical simulations of a rate equations model. The emitter, or master laser, is assumed to be an external-cavity single-mode semiconductor laser subject to optical feedback that operates in a chaotic regime. The receiver, or slave laser, is similar to the emitter but can either operate in a chaotic regime, as the emitter (closed loop configuration), or without optical feedback and consequently under CW when it is uncoupled (open loop configuration). This configuration is one of the most simple and useful configuration for chaos based communication systems and data encryption. To cite this article: C.R. Mirasso et al., C. R. Physique 5 (2004).

  8. Spot Welding of Honeycomb Structures

    Science.gov (United States)

    Cohal, V.

    2017-08-01

    Honeycomb structures are used to prepare meals water jet cutting machines for textile. These honeycomb structures are made of stainless steel sheet thickness of 0.1-0.2 mm. Corrugated sheet metal strips are between two gears with special tooth profile. Hexagonal cells for obtaining these strips are welded points between them. Spot welding device is three electrodes in the upper part, which carries three welding points across the width of the strip of corrugated sheet metal. Spot welding device filled with press and advance mechanisms. The paper presents the values of the regime for spot welding.

  9. Laser spot detection based on reaction diffusion

    Czech Academy of Sciences Publication Activity Database

    Vázquez-Otero, Alejandro; Khikhlukha, Danila; Solano-Altamirano, J. M.; Dormido, R.; Duro, N.

    2016-01-01

    Roč. 16, č. 3 (2016), s. 1-11, č. článku 315. ISSN 1424-8220 R&D Projects: GA MŠk EF15_008/0000162 Grant - others:ELI Beamlines(XE) CZ.02.1.01/0.0/0.0/15_008/0000162 Institutional support: RVO:68378271 Keywords : laser spot detection * laser beam detection * reaction diffusion models * Fitzhugh-Nagumo model * reaction diffusion computation * Turing patterns Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 2.677, year: 2016

  10. Data transmission system with encryption by chaotic sequences

    Directory of Open Access Journals (Sweden)

    Politans’kyy R. L.

    2014-06-01

    Full Text Available Protection of transferable information in the telecommunication systems is possible by its imposition of coding sequence on a plaintext. Encryption of pseudorandom sequences can be performed by using generation algorithms which are implemented on the basis of the phenomenon of dynamical chaos, which is sensitive to changes in the initial conditions. One of the major problems encountered in the construction of secure communication systems is to provide synchronization between the receiving and transmitting parties of communication systems. Improvement of methods of hidden data transfer based on the systems with chaotic synchronization is the important task of research in the field of information and telecommunication systems based on chaos. This article shows an implementation of a data transmission system, encrypted by sequences, generated on the basis of one-dimensional discrete chaotic maps with ensuring synchronization of the transmitting and receiving sides of the system. In this system realization of synchronization is offered by a transmission through certain time domains of current value of xn generated by a logistic reflection. Xn transmission period depends on computer speed and distance between subscribers of the system. Its value is determined by transmitting a test message before the session. Infallible reception of test message indicates the optimal choice of a transmission period of the current value of xn. Selection period is done at the program level. For the construction of communication network modern software was used, in particular programming language Delphi 7.0. The work of the system is shown on the example of information transmission between the users of the system. The system operates in real time full duplex mode at any hardware implementation of Internet access. It is enough for the users of the system to specify IP address only.

  11. Secure searching of biomarkers through hybrid homomorphic encryption scheme.

    Science.gov (United States)

    Kim, Miran; Song, Yongsoo; Cheon, Jung Hee

    2017-07-26

    As genome sequencing technology develops rapidly, there has lately been an increasing need to keep genomic data secure even when stored in the cloud and still used for research. We are interested in designing a protocol for the secure outsourcing matching problem on encrypted data. We propose an efficient method to securely search a matching position with the query data and extract some information at the position. After decryption, only a small amount of comparisons with the query information should be performed in plaintext state. We apply this method to find a set of biomarkers in encrypted genomes. The important feature of our method is to encode a genomic database as a single element of polynomial ring. Since our method requires a single homomorphic multiplication of hybrid scheme for query computation, it has the advantage over the previous methods in parameter size, computation complexity, and communication cost. In particular, the extraction procedure not only prevents leakage of database information that has not been queried by user but also reduces the communication cost by half. We evaluate the performance of our method and verify that the computation on large-scale personal data can be securely and practically outsourced to a cloud environment during data analysis. It takes about 3.9 s to search-and-extract the reference and alternate sequences at the queried position in a database of size 4M. Our solution for finding a set of biomarkers in DNA sequences shows the progress of cryptographic techniques in terms of their capability can support real-world genome data analysis in a cloud environment.

  12. Separable and Error-Free Reversible Data Hiding in Encrypted Image with High Payload

    Directory of Open Access Journals (Sweden)

    Zhaoxia Yin

    2014-01-01

    Full Text Available This paper proposes a separable reversible data-hiding scheme in encrypted image which offers high payload and error-free data extraction. The cover image is partitioned into nonoverlapping blocks and multigranularity encryption is applied to obtain the encrypted image. The data hider preprocesses the encrypted image and randomly selects two basic pixels in each block to estimate the block smoothness and indicate peak points. Additional data are embedded into blocks in the sorted order of block smoothness by using local histogram shifting under the guidance of the peak points. At the receiver side, image decryption and data extraction are separable and can be free to choose. Compared to previous approaches, the proposed method is simpler in calculation while offering better performance: larger payload, better embedding quality, and error-free data extraction, as well as image recovery.

  13. Multiple image encryption scheme based on pixel exchange operation and vector decomposition

    Science.gov (United States)

    Xiong, Y.; Quan, C.; Tay, C. J.

    2018-02-01

    We propose a new multiple image encryption scheme based on a pixel exchange operation and a basic vector decomposition in Fourier domain. In this algorithm, original images are imported via a pixel exchange operator, from which scrambled images and pixel position matrices are obtained. Scrambled images encrypted into phase information are imported using the proposed algorithm and phase keys are obtained from the difference between scrambled images and synthesized vectors in a charge-coupled device (CCD) plane. The final synthesized vector is used as an input in a random phase encoding (DRPE) scheme. In the proposed encryption scheme, pixel position matrices and phase keys serve as additional private keys to enhance the security of the cryptosystem which is based on a 4-f system. Numerical simulations are presented to demonstrate the feasibility and robustness of the proposed encryption scheme.

  14. Optical image encryption using QR code and multilevel fingerprints in gyrator transform domains

    Science.gov (United States)

    Wei, Yang; Yan, Aimin; Dong, Jiabin; Hu, Zhijuan; Zhang, Jingtao

    2017-11-01

    A new concept of GT encryption scheme is proposed in this paper. We present a novel optical image encryption method by using quick response (QR) code and multilevel fingerprint keys in gyrator transform (GT) domains. In this method, an original image is firstly transformed into a QR code, which is placed in the input plane of cascaded GTs. Subsequently, the QR code is encrypted into the cipher-text by using multilevel fingerprint keys. The original image can be obtained easily by reading the high-quality retrieved QR code with hand-held devices. The main parameters used as private keys are GTs' rotation angles and multilevel fingerprints. Biometrics and cryptography are integrated with each other to improve data security. Numerical simulations are performed to demonstrate the validity and feasibility of the proposed encryption scheme. In the future, the method of applying QR codes and fingerprints in GT domains possesses much potential for information security.

  15. Dual-channel in-line digital holographic double random phase encryption.

    Science.gov (United States)

    Das, Bhargab; Yelleswarapu, Chandra S; Rao, D V G L N

    2012-10-01

    We present a robust encryption method for the encoding of 2D/3D objects using digital holography and virtual optics. Using our recently developed dual-plane in-line digital holography technique, two in-line digital holograms are recorded at two different planes and are encrypted using two different double random phase encryption configurations, independently. The process of using two mutually exclusive encryption channels makes the system more robust against attacks since both the channels should be decrypted accurately in order to get a recognizable reconstruction. Results show that the reconstructed object is unrecognizable even when the portion of the correct phase keys used during decryption is close to 75%. The system is verified against blind decryptions by evaluating the SNR and MSE. Validation of the proposed method and sensitivities of the associated parameters are quantitatively analyzed and illustrated.

  16. Choice of optical system is critical for the security of double random phase encryption systems

    Science.gov (United States)

    Muniraj, Inbarasan; Guo, Changliang; Malallah, Ra'ed; Cassidy, Derek; Zhao, Liang; Ryle, James P.; Healy, John J.; Sheridan, John T.

    2017-06-01

    The linear canonical transform (LCT) is used in modeling a coherent light-field propagation through first-order optical systems. Recently, a generic optical system, known as the quadratic phase encoding system (QPES), for encrypting a two-dimensional image has been reported. In such systems, two random phase keys and the individual LCT parameters (α,β,γ) serve as secret keys of the cryptosystem. It is important that such encryption systems also satisfy some dynamic security properties. We, therefore, examine such systems using two cryptographic evaluation methods, the avalanche effect and bit independence criterion, which indicate the degree of security of the cryptographic algorithms using QPES. We compared our simulation results with the conventional Fourier and the Fresnel transform-based double random phase encryption (DRPE) systems. The results show that the LCT-based DRPE has an excellent avalanche and bit independence characteristics compared to the conventional Fourier and Fresnel-based encryption systems.

  17. 75 FR 43819 - Clarification of Grace Period for Encryption Registration Requirement

    Science.gov (United States)

    2010-07-27

    ... the definition at Sec. 734.2(b)(9) for encryption software) under Sec. 742.15(b)(1) for the first time.... 15 CFR Part 742 Exports, Terrorism. 0 Accordingly, the Bureau of Industry and Security amends its...

  18. Experimental scrambling and noise reduction applied to the optical encryption of QR codes.

    Science.gov (United States)

    Barrera, John Fredy; Vélez, Alejandro; Torroba, Roberto

    2014-08-25

    In this contribution, we implement two techniques to reinforce optical encryption, which we restrict in particular to the QR codes, but could be applied in a general encoding situation. To our knowledge, we present the first experimental-positional optical scrambling merged with an optical encryption procedure. The inclusion of an experimental scrambling technique in an optical encryption protocol, in particular dealing with a QR code "container", adds more protection to the encoding proposal. Additionally, a nonlinear normalization technique is applied to reduce the noise over the recovered images besides increasing the security against attacks. The opto-digital techniques employ an interferometric arrangement and a joint transform correlator encrypting architecture. The experimental results demonstrate the capability of the methods to accomplish the task.

  19. A Novel Model for Lattice-Based Authorized Searchable Encryption with Special Keyword

    Directory of Open Access Journals (Sweden)

    Fugeng Zeng

    2015-01-01

    Full Text Available Data stored in the cloud servers, keyword search, and access controls are two important capabilities which should be supported. Public-keyword encryption with keyword search (PEKS and attribute based encryption (ABE are corresponding solutions. Meanwhile, as we step into postquantum era, pairing related assumption is fragile. Lattice is an ideal choice for building secure encryption scheme against quantum attack. Based on this, we propose the first mathematical model for lattice-based authorized searchable encryption. Data owners can sort the ciphertext by specific keywords such as time; data users satisfying the access control hand the trapdoor generated with the keyword to the cloud sever; the cloud sever sends back the corresponding ciphertext. The security of our schemes is based on the worst-case hardness on lattices, called learning with errors (LWE assumption. In addition, our scheme achieves attribute-hiding, which could protect the sensitive information of data user.

  20. A Novel Image Encryption Algorithm Based on DNA Encoding and Spatiotemporal Chaos

    Directory of Open Access Journals (Sweden)

    Chunyan Song

    2015-10-01

    Full Text Available DNA computing based image encryption is a new, promising field. In this paper, we propose a novel image encryption scheme based on DNA encoding and spatiotemporal chaos. In particular, after the plain image is primarily diffused with the bitwise Exclusive-OR operation, the DNA mapping rule is introduced to encode the diffused image. In order to enhance the encryption, the spatiotemporal chaotic system is used to confuse the rows and columns of the DNA encoded image. The experiments demonstrate that the proposed encryption algorithm is of high key sensitivity and large key space, and it can resist brute-force attack, entropy attack, differential attack, chosen-plaintext attack, known-plaintext attack and statistical attack.

  1. 15 CFR Supplement No. 6 to Part 742 - Guidelines for Submitting Review Requests for Encryption Items

    Science.gov (United States)

    2010-01-01

    ...) State all communication protocols (e.g., X.25, Telnet, TCP, IEEE 802.11, IEEE 802.16, SIP * * *) and... the encryption algorithms, key management and key space. (11) License Exception ENC 'Restricted...

  2. Efficient secure-channel free public key encryption with keyword search for EMRs in cloud storage.

    Science.gov (United States)

    Guo, Lifeng; Yau, Wei-Chuen

    2015-02-01

    Searchable encryption is an important cryptographic primitive that enables privacy-preserving keyword search on encrypted electronic medical records (EMRs) in cloud storage. Efficiency of such searchable encryption in a medical cloud storage system is very crucial as it involves client platforms such as smartphones or tablets that only have constrained computing power and resources. In this paper, we propose an efficient secure-channel free public key encryption with keyword search (SCF-PEKS) scheme that is proven secure in the standard model. We show that our SCF-PEKS scheme is not only secure against chosen keyword and ciphertext attacks (IND-SCF-CKCA), but also secure against keyword guessing attacks (IND-KGA). Furthermore, our proposed scheme is more efficient than other recent SCF-PEKS schemes in the literature.

  3. DATA SECURITY IN LOCAL AREA NETWORK BASED ON FAST ENCRYPTION ALGORITHM

    Directory of Open Access Journals (Sweden)

    G. Ramesh

    2010-06-01

    Full Text Available Hacking is one of the greatest problems in the wireless local area networks. Many algorithms have been used to prevent the outside attacks to eavesdrop or prevent the data to be transferred to the end-user safely and correctly. In this paper, a new symmetrical encryption algorithm is proposed that prevents the outside attacks. The new algorithm avoids key exchange between users and reduces the time taken for the encryption and decryption. It operates at high data rate in comparison with The Data Encryption Standard (DES, Triple DES (TDES, Advanced Encryption Standard (AES-256, and RC6 algorithms. The new algorithm is applied successfully on both text file and voice message.

  4. Optical stream-cipher-like system for image encryption based on Michelson interferometer.

    Science.gov (United States)

    Yang, Bing; Liu, Zhengjun; Wang, Bo; Zhang, Yan; Liu, Shutian

    2011-01-31

    A novel optical image encryption scheme based on interference is proposed. The original image is digitally encoded into one phase-only mask by employing an improved Gerchberg-Saxton phase retrieval algorithm together with another predefined random phase mask which serves as the encryption key. The decryption process can be implemented optically based on Michelson interferometer by using the same key. The scheme can be regarded as a stream-cipher-like encryption system, the encryption and decryption keys are the same, however the operations are different. The position coordinates and light wavelength can also be used as additional keys during the decryption. Numerical simulations have demonstrated the validity and robustness of the proposed method.

  5. Quantum-Enhanced Cyber Security: Experimental Computation on Quantum-Encrypted Data

    Science.gov (United States)

    2017-03-02

    AFRL-AFOSR-UK-TR-2017-0020 Quantum -Enhanced Cyber Security: Experimental Computation on Quantum -Encrypted Data Philip Walther UNIVERSITT WIEN Final...REPORT TYPE Final 3. DATES COVERED (From - To) 15 Oct 2015 to 31 Dec 2016 4. TITLE AND SUBTITLE Quantum -Enhanced Cyber Security: Experimental Computation ...project developed methods and technologies are necessary prerequisites for performing experimental quantum computations with quantum -encrypted data. Even

  6. LEE: Light‐Weight Energy‐Efficient encryption algorithm for sensor networks

    OpenAIRE

    Komninos, N.; Soroush, H.; Salajegheh, M.

    2007-01-01

    Data confidentiality in wireless sensor networks is mainly achieved by RC5 and Skipjack encryption algorithms. However, both algorithms have their weaknesses, for example RC5 supports variable-bit rotations, which are computationally expensive operations and Skipjack uses a key length of 80-bits, which is subject to brute force attack. In this paper we introduce a light-weight energy- fficient encryption-algorithm (LEE) for tiny embedded devices, such as sensor network nodes. We present exper...

  7. Bit-level plane image encryption based on coupled map lattice with time-varying delay

    Science.gov (United States)

    Lv, Xiupin; Liao, Xiaofeng; Yang, Bo

    2018-04-01

    Most of the existing image encryption algorithms had two basic properties: confusion and diffusion in a pixel-level plane based on various chaotic systems. Actually, permutation in a pixel-level plane could not change the statistical characteristics of an image, and many of the existing color image encryption schemes utilized the same method to encrypt R, G and B components, which means that the three color components of a color image are processed three times independently. Additionally, dynamical performance of a single chaotic system degrades greatly with finite precisions in computer simulations. In this paper, a novel coupled map lattice with time-varying delay therefore is applied in color images bit-level plane encryption to solve the above issues. Spatiotemporal chaotic system with both much longer period in digitalization and much excellent performances in cryptography is recommended. Time-varying delay embedded in coupled map lattice enhances dynamical behaviors of the system. Bit-level plane image encryption algorithm has greatly reduced the statistical characteristics of an image through the scrambling processing. The R, G and B components cross and mix with one another, which reduces the correlation among the three components. Finally, simulations are carried out and all the experimental results illustrate that the proposed image encryption algorithm is highly secure, and at the same time, also demonstrates superior performance.

  8. A Novel Image Encryption Algorithm Based on a Fractional-Order Hyperchaotic System and DNA Computing

    Directory of Open Access Journals (Sweden)

    Taiyong Li

    2017-01-01

    Full Text Available In the era of the Internet, image encryption plays an important role in information security. Chaotic systems and DNA operations have been proven to be powerful for image encryption. To further enhance the security of image, in this paper, we propose a novel algorithm that combines the fractional-order hyperchaotic Lorenz system and DNA computing (FOHCLDNA for image encryption. Specifically, the algorithm consists of four parts: firstly, we use a fractional-order hyperchaotic Lorenz system to generate a pseudorandom sequence that will be utilized during the whole encryption process; secondly, a simple but effective diffusion scheme is performed to spread the little change in one pixel to all the other pixels; thirdly, the plain image is encoded by DNA rules and corresponding DNA operations are performed; finally, global permutation and 2D and 3D permutation are performed on pixels, bits, and acid bases. The extensive experimental results on eight publicly available testing images demonstrate that the encryption algorithm can achieve state-of-the-art performance in terms of security and robustness when compared with some existing methods, showing that the FOHCLDNA is promising for image encryption.

  9. 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.

  10. Ensemble of Chaotic and Naive Approaches for Performance Enhancement in Video Encryption

    Directory of Open Access Journals (Sweden)

    Jeyamala Chandrasekaran

    2015-01-01

    Full Text Available Owing to the growth of high performance network technologies, multimedia applications over the Internet are increasing exponentially. Applications like video conferencing, video-on-demand, and pay-per-view depend upon encryption algorithms for providing confidentiality. Video communication is characterized by distinct features such as large volume, high redundancy between adjacent frames, video codec compliance, syntax compliance, and application specific requirements. Naive approaches for video encryption encrypt the entire video stream with conventional text based cryptographic algorithms. Although naive approaches are the most secure for video encryption, the computational cost associated with them is very high. This research work aims at enhancing the speed of naive approaches through chaos based S-box design. Chaotic equations are popularly known for randomness, extreme sensitivity to initial conditions, and ergodicity. The proposed methodology employs two-dimensional discrete Henon map for (i generation of dynamic and key-dependent S-box that could be integrated with symmetric algorithms like Blowfish and Data Encryption Standard (DES and (ii generation of one-time keys for simple substitution ciphers. The proposed design is tested for randomness, nonlinearity, avalanche effect, bit independence criterion, and key sensitivity. Experimental results confirm that chaos based S-box design and key generation significantly reduce the computational cost of video encryption with no compromise in security.

  11. Substring Position Search over Encrypted Cloud Data Supporting Efficient Multi-User Setup

    Directory of Open Access Journals (Sweden)

    Mikhail Strizhov

    2016-07-01

    Full Text Available Existing Searchable Encryption (SE solutions are able to handle simple Boolean search queries, such as single or multi-keyword queries, but cannot handle substring search queries over encrypted data that also involve identifying the position of the substring within the document. These types of queries are relevant in areas such as searching DNA data. In this paper, we propose a tree-based Substring Position Searchable Symmetric Encryption (SSP-SSE to overcome the existing gap. Our solution efficiently finds occurrences of a given substring over encrypted cloud data. Specifically, our construction uses the position heap tree data structure and achieves asymptotic efficiency comparable to that of an unencrypted position heap tree. Our encryption takes O ( k n time, and the resulting ciphertext is of size O ( k n , where k is a security parameter and n is the size of stored data. The search takes O ( m 2 + o c c time and three rounds of communication, where m is the length of the queried substring and o c c is the number of occurrences of the substring in the document collection. We prove that the proposed scheme is secure against chosen-query attacks that involve an adaptive adversary. Finally, we extend SSP-SSE to the multi-user setting where an arbitrary group of cloud users can submit substring queries to search the encrypted data.

  12. Phase image encryption of colored images using double random phase encoding technique in HSV color space

    Science.gov (United States)

    Joshi, Madhusudan; Shakher, Chandra; Singh, Kehar

    2009-09-01

    A double random phase encoding based digital phase encryption technique for colored images is proposed in the Fourier domain. The RGB input image is brought to HSV color space and then converted into phase, prior to the encryption. In the decryption process the HSV image is and converted back to the RGB format. The random phase codes used during encryption are prepared by stacking three two-dimensional random phase masks. These random phase codes serve as keys for encryption and decryption. The proposed technique carries all the advantages of phase encryption and is supposedly three-dimensional in nature. Robustness of the technique is analyzed against the variations in random phase codes and shuffling of the random phase masks of a given phase code. Performance of the scheme is also verified against occlusion of Fourier plane random phase code as well as the encrypted image. Effects of noise attacks and attacks using partial windows of correct random phase codes have also been checked. Digital simulations are presented to support the idea.

  13. Privacy-Aware Image Encryption Based on Logistic Map and Data Hiding

    Science.gov (United States)

    Sun, Jianglin; Liao, Xiaofeng; Chen, Xin; Guo, Shangwei

    The increasing need for image communication and storage has created a great necessity for securely transforming and storing images over a network. Whereas traditional image encryption algorithms usually consider the security of the whole plain image, region of interest (ROI) encryption schemes, which are of great importance in practical applications, protect the privacy regions of plain images. Existing ROI encryption schemes usually adopt approximate techniques to detect the privacy region and measure the quality of encrypted images; however, their performance is usually inconsistent with a human visual system (HVS) and is sensitive to statistical attacks. In this paper, we propose a novel privacy-aware ROI image encryption (PRIE) scheme based on logistical mapping and data hiding. The proposed scheme utilizes salient object detection to automatically, adaptively and accurately detect the privacy region of a given plain image. After private pixels have been encrypted using chaotic cryptography, the significant bits are embedded into the nonprivacy region of the plain image using data hiding. Extensive experiments are conducted to illustrate the consistency between our automatic ROI detection and HVS. Our experimental results also demonstrate that the proposed scheme exhibits satisfactory security performance.

  14. Image encryption scheme based on computer generated holography and time-averaged moiré

    Science.gov (United States)

    Palevicius, Paulius; Ragulskis, Minvydas; Janusas, Giedrius; Palevicius, Arvydas

    2017-08-01

    A technique of computational image encryption and optical decryption based on computer generated holography and time-averaged moiŕe is investigated in this paper. Dynamic visual cryptography (a visual cryptography scheme based on time-averaging geometric moiŕe), Gerchberg-Saxton algorithm and 3D microstructure manufacturing techniques are used to construct the optical scheme. The secret is embedded into a cover image by using a stochastic moiŕe grating and can be visually decoded by a naked eye. The secret is revealed if the amplitude of harmonic oscillations in the Fourier plane corresponds to an accurately preselected value. The process of the production of 3D microstructure is described in details. Computer generated holography is used in the design step and electron beam lithography is exploited for physical 3D patterning. The phase data of a complex 3D microstructure is obtained by Gerchberg-Saxton algorithm and is used to produce a computer generated hologram. Physical implementation of microstructure is performed by using a single layer polymethyl methacrylate as a basis for 3D microstructure. Numerical simulations demonstrate efficient applicability of this technique.

  15. High security chaotic multiple access scheme for visible light communication systems with advanced encryption standard interleaving

    Science.gov (United States)

    Qiu, Junchao; Zhang, Lin; Li, Diyang; Liu, Xingcheng

    2016-06-01

    Chaotic sequences can be applied to realize multiple user access and improve the system security for a visible light communication (VLC) system. However, since the map patterns of chaotic sequences are usually well known, eavesdroppers can possibly derive the key parameters of chaotic sequences and subsequently retrieve the information. We design an advanced encryption standard (AES) interleaving aided multiple user access scheme to enhance the security of a chaotic code division multiple access-based visible light communication (C-CDMA-VLC) system. We propose to spread the information with chaotic sequences, and then the spread information is interleaved by an AES algorithm and transmitted over VLC channels. Since the computation complexity of performing inverse operations to deinterleave the information is high, the eavesdroppers in a high speed VLC system cannot retrieve the information in real time; thus, the system security will be enhanced. Moreover, we build a mathematical model for the AES-aided VLC system and derive the theoretical information leakage to analyze the system security. The simulations are performed over VLC channels, and the results demonstrate the effectiveness and high security of our presented AES interleaving aided chaotic CDMA-VLC system.

  16. Linkage of tobiano coat spotting and albumin markers in a pony family.

    Science.gov (United States)

    Trommershausen-Smith, A

    1978-01-01

    Genetic segregation patterns among blood type markers and various phenotypically observed traits were studied in a small herd of ponies. The herd consisted of 10 mares without white spotting and a single stallion with the dominant pattern of tobiano spotting. Comparison of segregation patterns at loci for which the stallion was heterozygous showed tight linkage for the Alb-B and tobiano markers. In 17 cases in which the Alb contribution of the sire could be determined, all 10 foals that inherited AlbB from him were tobiano spotted, and all 7 non-spotted foals inherited his AlbA. The use of the symbol To is proposed for dominantly inherited tobiano spotting linked to the albumin.

  17. All-optical encryption/decryption for nonreturn-to-zero differential phase-shift keying signals using four-wave mixing in semiconductor optical amplifier

    Science.gov (United States)

    Yang, Xuelin; Zhou, Peng; Hu, Xiaonan; Hu, Weisheng

    2015-04-01

    By experiment we demonstrate an all-optical encryption/decryption scheme for nonreturn-to-zero differential phase-shift keying (NRZ-DPSK) signals at 10 Gbit/s using all-optical exclusive-OR (XOR) logic. The key bit stream is performed by a pseudorandom bit stream. The all-optical XOR logic is achieved by nondegenerate four-wave mixing (FWM) in a semiconductor optical amplifier (SOA), which allows high data rate operation and asymmetric optical powers of the two input bit streams. The gain dynamics and pattern effect associated with the SOA carrier lifetime are alleviated due to the constant envelope of the NRZ-DPSK signals.

  18. Spot Variance Path Estimation and its Application to High Frequency Jump Testing

    NARCIS (Netherlands)

    Bos, C.S.; Janus, P.; Koopman, S.J.

    2012-01-01

    This paper considers spot variance path estimation from datasets of intraday high-frequency asset prices in the presence of diurnal variance patterns, jumps, leverage effects, and microstructure noise. We rely on parametric and nonparametric methods. The estimated spot variance path can be used to

  19. 9 CFR 149.4 - Spot audit.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Spot audit. 149.4 Section 149.4... LIVESTOCK IMPROVEMENT VOLUNTARY TRICHINAE CERTIFICATION PROGRAM § 149.4 Spot audit. (a) In addition to regularly scheduled site audits, certified production sites will be subject to spot audits. (1) Random spot...

  20. Secure transmission of static and dynamic images via chaotic encryption in acousto-optic hybrid feedback with profiled light beams

    Science.gov (United States)

    Chatterjee, Monish R.; Almehmadi, Fares S.

    2015-01-01

    Secure information encryption via acousto-optic (AO) chaos with profiled optical beams indicates substantially better performance in terms of system robustness. This paper examines encryption of static and time-varying (video) images onto AO chaotic carriers using Gaussian-profile beams with diffracted data numerically generated using transfer functions. The use of profiled beams leads to considerable improvement in the encrypted signal. While static image encryption exhibits parameter tolerances within about +/-10% for uniform optical beams, profiled beams reduce the tolerance to less than 1%, thereby vastly improving both the overall security of the transmitted information as well as the quality of the image retrieval.

  1. Nonlinear image encryption using a fully phase nonzero-order joint transform correlator in the Gyrator domain

    Science.gov (United States)

    Vilardy, Juan M.; Millán, María S.; Pérez-Cabré, Elisabet

    2017-02-01

    A novel nonlinear image encryption scheme based on a fully phase nonzero-order joint transform correlator architecture (JTC) in the Gyrator domain (GD) is proposed. In this encryption scheme, the two non-overlapping data distributions of the input plane of the JTC are fully encoded in phase and this input plane is transformed using the Gyrator transform (GT); the intensity distribution captured in the GD represents a new definition of the joint Gyrator power distribution (JGPD). The JGPD is modified by two nonlinear operations with the purpose of retrieving the encrypted image, with enhancement of the decrypted signal quality and improvement of the overall security. There are three keys used in the encryption scheme, two random phase masks and the rotation angle of the GT, which are all necessary for a proper decryption. Decryption is highly sensitivity to changes of the rotation angle of the GT as well as to little changes in other parameters or keys. The proposed encryption scheme in the GD still preserves the shift-invariance properties originated in the JTC-based encryption in the Fourier domain. The proposed encryption scheme is more resistant to brute force attacks, chosen-plaintext attacks, known-plaintext attacks, and ciphertext-only attacks, as they have been introduced in the cryptanalysis of the JTC-based encryption system. Numerical results are presented and discussed in order to verify and analyze the feasibility and validity of the novel encryption-decryption scheme.

  2. On the origin of delta spots

    International Nuclear Information System (INIS)

    Tang, F.

    1983-01-01

    Mount Wilson sunspot drawings from 1966 through 1980 were used in conjunction with Hα filtergrams from Big Bear Solar Observatory to examine the origin of delta spots, spots with bipolar umbrae within one penumbra. Of the six cases we studied, five were formed by the union of non-paired spots. They are either shoved into one another by two neighboring growing bipoles or by a new spot born piggy-back style on an existing spot of opposite polarity. Proper motions of the growing spots take on curvilinear paths around one another to avoid a collision. This is the shear motion observed in delta spots (Tanaka, 1979). In the remaining case, the delta spot was formed by spots that emerged as a pair. Our findings indicate no intrinsic differences in the formation or the behavior between delta spots of normal magnetic configuration. (orig.)

  3. Encryption for Remote Control via Internet or Intranet

    Science.gov (United States)

    Lineberger, Lewis

    2005-01-01

    A data-communication protocol has been devised to enable secure, reliable remote control of processes and equipment via a collision-based network, while using minimal bandwidth and computation. The network could be the Internet or an intranet. Control is made secure by use of both a password and a dynamic key, which is sent transparently to a remote user by the controlled computer (that is, the computer, located at the site of the equipment or process to be controlled, that exerts direct control over the process). The protocol functions in the presence of network latency, overcomes errors caused by missed dynamic keys, and defeats attempts by unauthorized remote users to gain control. The protocol is not suitable for real-time control, but is well suited for applications in which control latencies up to about 0.5 second are acceptable. The encryption scheme involves the use of both a dynamic and a private key, without any additional overhead that would degrade performance. The dynamic key is embedded in the equipment- or process-monitor data packets sent out by the controlled computer: in other words, the dynamic key is a subset of the data in each such data packet. The controlled computer maintains a history of the last 3 to 5 data packets for use in decrypting incoming control commands. In addition, the controlled computer records a private key (password) that is given to the remote computer. The encrypted incoming command is permuted by both the dynamic and private key. A person who records the command data in a given packet for hostile purposes cannot use that packet after the public key expires (typically within 3 seconds). Even a person in possession of an unauthorized copy of the command/remote-display software cannot use that software in the absence of the password. The use of a dynamic key embedded in the outgoing data makes the central-processing unit overhead very small. The use of a National Instruments DataSocket(TradeMark) (or equivalent) protocol or

  4. Quantum cryptography using coherent states: Randomized encryption and key generation

    Science.gov (United States)

    Corndorf, Eric

    objectives of key generation and direct data-encryption, a new quantum cryptographic principle is demonstrated wherein keyed coherent-state signal sets are employed. Taking advantage of the fundamental and irreducible quantum-measurement noise of coherent states, these schemes do not require the users to measure the influence of an attacker. Experimental key-generation and data encryption schemes based on these techniques, which are compatible with today's WDM fiber-optic telecommunications infrastructure, are implemented and analyzed.

  5. Interpolating Spline Curve-Based Perceptual Encryption for 3D Printing Models

    Directory of Open Access Journals (Sweden)

    Giao N. Pham

    2018-02-01

    Full Text Available With the development of 3D printing technology, 3D printing has recently been applied to many areas of life including healthcare and the automotive industry. Due to the benefit of 3D printing, 3D printing models are often attacked by hackers and distributed without agreement from the original providers. Furthermore, certain special models and anti-weapon models in 3D printing must be protected against unauthorized users. Therefore, in order to prevent attacks and illegal copying and to ensure that all access is authorized, 3D printing models should be encrypted before being transmitted and stored. A novel perceptual encryption algorithm for 3D printing models for secure storage and transmission is presented in this paper. A facet of 3D printing model is extracted to interpolate a spline curve of degree 2 in three-dimensional space that is determined by three control points, the curvature coefficients of degree 2, and an interpolating vector. Three control points, the curvature coefficients, and interpolating vector of the spline curve of degree 2 are encrypted by a secret key. The encrypted features of the spline curve are then used to obtain the encrypted 3D printing model by inverse interpolation and geometric distortion. The results of experiments and evaluations prove that the entire 3D triangle model is altered and deformed after the perceptual encryption process. The proposed algorithm is responsive to the various formats of 3D printing models. The results of the perceptual encryption process is superior to those of previous methods. The proposed algorithm also provides a better method and more security than previous methods.

  6. SPOTS Calibration Example

    Directory of Open Access Journals (Sweden)

    Patterson E.

    2010-06-01

    Full Text Available The results are presented using the procedure outlined by the Standardisation Project for Optical Techniques of Strain measurement to calibrate a digital image correlation system. The process involves comparing the experimental data obtained with the optical measurement system to the theoretical values for a specially designed specimen. The standard states the criteria which must be met in order to achieve successful calibration, in addition to quantifying the measurement uncertainty in the system. The system was evaluated at three different displacement load levels, generating strain ranges from 289 µstrain to 2110 µstrain. At the 289 µstrain range, the calibration uncertainty was found to be 14.1 µstrain, and at the 2110 µstrain range it was found to be 28.9 µstrain. This calibration procedure was performed without painting a speckle pattern on the surface of the metal. Instead, the specimen surface was prepared using different grades of grit paper to produce the desired texture.

  7. Exclusion of EDNRB and KIT as the basis for white spotting in Border Collies.

    Science.gov (United States)

    Metallinos, D; Rine, J

    2000-01-01

    White spotting patterns in mammals can be caused by mutations in the genes for the endothelin B receptor and c-Kit, whose protein products are necessary for proper migration, differentiation or survival of the melanoblast population of cells. Although there are many different dog breeds that segregate white spotting patterns, no genes have been identified that are linked to these phenotypes. An intercross was generated from a female Newfoundland and a male Border Collie and the white spotting phenotypes of the intercross progeny were evaluated by measuring percentage surface area of white in the puppies. The Border Collie markings segregated as a simple autosomal recessive (7/25 intercross progeny had the phenotype). Two candidate genes, for the endothelin B receptor (EDNRB) and c-Kit (KIT), were evaluated for segregation with the white spotting pattern. Polymorphisms between the Border Collie and Newfoundland were identified for EDNRB using Southern analysis after a portion of the canine gene had been cloned. Polymorphisms for KIT were identified using a microsatellite developed from a bacterial artificial chromosome containing the canine gene. Both EDNRB and KIT were excluded as a cause of the white spotting pattern in at least two of the intercross progeny. Although these genes have been implicated in white spotting in other mammals, including horses, pigs, cows, mice and rats, they do not appear to be responsible for the white spotting pattern found in the Border Collie breed of dog.

  8. Laser based spot weld characterization

    Science.gov (United States)

    Jonietz, Florian; Myrach, Philipp; Rethmeier, Michael; Suwala, Hubert; Ziegler, Mathias

    2016-02-01

    Spot welding is one of the most important joining technologies, especially in the automotive industry. Hitherto, the quality of spot welded joints is tested mainly by random destructive tests. A nondestructive testing technique offers the benefit of cost reduction of the testing procedure and optimization of the fabrication process, because every joint could be examined. This would lead to a reduced number of spot welded joints, as redundancies could be avoided. In the procedure described here, the spot welded joint between two zinc-coated steel sheets (HX340LAD+Z100MB or HC340LA+ZE 50/50) is heated optically on one side. Laser radiation and flash light are used as heat sources. The melted zone, the so called "weld nugget" provides the mechanical stability of the connection, but also constitutes a thermal bridge between the sheets. Due to the better thermal contact, the spot welded joint reveals a thermal behavior different from the surrounding material, where the heat transfer between the two sheets is much lower. The difference in the transient thermal behavior is measured with time resolved thermography. Hence, the size of the thermal contact between the two sheets is determined, which is directly correlated to the size of the weld nugget, indicating the quality of the spot weld. The method performs well in transmission with laser radiation and flash light. With laser radiation, it works even in reflection geometry, thus offering the possibility of testing with just one-sided accessibility. By using heating with collimated laser radiation, not only contact-free, but also remote testing is feasible. A further convenience compared to similar thermographic approaches is the applicability on bare steel sheets without any optical coating for emissivity correction. For this purpose, a proper way of emissivity correction was established.

  9. Security Property Validation of the Sensor Network Encryption Protocol (SNEP

    Directory of Open Access Journals (Sweden)

    Salekul Islam

    2015-07-01

    Full Text Available Since wireless sensor networks (WSNs have been designed to be deployed in an unsecured, public environment, secured communication is really vital for their wide-spread use. Among all of the communication protocols developed for WSN, the Security Protocols for Sensor Networks (SPINS is exceptional, as it has been designed with security as a goal. SPINS is composed of two building blocks: Secure Network Encryption Protocol (SNEP and the “micro” version of the Timed Efficient Streaming Loss-tolerant Authentication (TESLA, named μTESLA. From the inception of SPINS, a number of efforts have been made to validate its security properties. In this paper, we have validated the security properties of SNEP by using an automated security protocol validation tool, named AVISPA. Using the protocol specification language, HLPSL, we model two combined scenarios—node to node key agreement and counter exchange protocols—followed by data transmission. Next, we validate the security properties of these combined protocols, using different AVISPA back-ends. AVISPA reports the models we have developed free from attacks. However, by analyzing the key distribution sub-protocol, we find one threat of a potential DoS attack that we have demonstrated by modeling in AVISPA. Finally, we propose a modification, and AVISPA reports this modified version free from the potential DoS attack.

  10. Web-browser encryption of personal health information.

    Science.gov (United States)

    Morse, Richard E; Nadkarni, Prakash; Schoenfeld, David A; Finkelstein, Dianne M

    2011-11-10

    Electronic health records provide access to an unprecedented amount of clinical data for research that can accelerate the development of effective medical practices. However it is important to protect patient confidentiality, as many medical conditions are stigmatized and disclosure could result in personal and/or financial loss. We describe a system for remote data entry that allows the data that would identify the patient to be encrypted in the web browser of the person entering the data. These data cannot be decrypted on the server by the staff at the data center but can be decrypted by the person entering the data or their delegate. We developed this system to solve a problem that arose in the context of clinical research, but it is applicable in a range of situations where sensitive information is stored and updated in a database and it is necessary to ensure that it cannot be viewed by any except those intentionally given access. By developing this system, we are able to centralize the collection of some patient data while minimizing the risk that protected health information be made available to study personnel who are not authorized to use it.

  11. Web-browser encryption of personal health information

    Directory of Open Access Journals (Sweden)

    Morse Richard E

    2011-11-01

    Full Text Available Abstract Background Electronic health records provide access to an unprecedented amount of clinical data for research that can accelerate the development of effective medical practices. However it is important to protect patient confidentiality, as many medical conditions are stigmatized and disclosure could result in personal and/or financial loss. Results We describe a system for remote data entry that allows the data that would identify the patient to be encrypted in the web browser of the person entering the data. These data cannot be decrypted on the server by the staff at the data center but can be decrypted by the person entering the data or their delegate. We developed this system to solve a problem that arose in the context of clinical research, but it is applicable in a range of situations where sensitive information is stored and updated in a database and it is necessary to ensure that it cannot be viewed by any except those intentionally given access. Conclusion By developing this system, we are able to centralize the collection of some patient data while minimizing the risk that protected health information be made available to study personnel who are not authorized to use it.

  12. Optimal Rate Private Information Retrieval from Homomorphic Encryption

    Directory of Open Access Journals (Sweden)

    Kiayias Aggelos

    2015-06-01

    Full Text Available We consider the problem of minimizing the communication in single-database private information retrieval protocols in the case where the length of the data to be transmitted is large. We present first rate-optimal protocols for 1-out-of-n computationallyprivate information retrieval (CPIR, oblivious transfer (OT, and strong conditional oblivious transfer (SCOT. These protocols are based on a new optimalrate leveled homomorphic encryption scheme for large-output polynomial-size branching programs, that might be of independent interest. The analysis of the new scheme is intricate: the optimal rate is achieved if a certain parameter s is set equal to the only positive root of a degree-(m + 1 polynomial, where m is the length of the branching program. We show, by using Galois theory, that even when m = 4, this polynomial cannot be solved in radicals. We employ the Newton-Puiseux algorithm to find a Puiseux series for s, and based on this, propose a Θ (logm-time algorithm to find an integer approximation to s.

  13. Cryptographically Secure Multiparty Computation and Distributed Auctions Using Homomorphic Encryption

    Directory of Open Access Journals (Sweden)

    Anunay Kulshrestha

    2017-12-01

    Full Text Available We introduce a robust framework that allows for cryptographically secure multiparty computations, such as distributed private value auctions. The security is guaranteed by two-sided authentication of all network connections, homomorphically encrypted bids, and the publication of zero-knowledge proofs of every computation. This also allows a non-participant verifier to verify the result of any such computation using only the information broadcasted on the network by each individual bidder. Building on previous work on such systems, we design and implement an extensible framework that puts the described ideas to practice. Apart from the actual implementation of the framework, our biggest contribution is the level of protection we are able to guarantee from attacks described in previous work. In order to provide guidance to users of the library, we analyze the use of zero knowledge proofs in ensuring the correct behavior of each node in a computation. We also describe the usage of the library to perform a private-value distributed auction, as well as the other challenges in implementing the protocol, such as auction registration and certificate distribution. Finally, we provide performance statistics on our implementation of the auction.

  14. Probing protein sequences as sources for encrypted antimicrobial peptides.

    Science.gov (United States)

    Brand, Guilherme D; Magalhães, Mariana T Q; Tinoco, Maria L P; Aragão, Francisco J L; Nicoli, Jacques; Kelly, Sharon M; Cooper, Alan; Bloch, Carlos

    2012-01-01

    Starting from the premise that a wealth of potentially biologically active peptides may lurk within proteins, we describe here a methodology to identify putative antimicrobial peptides encrypted in protein sequences. Candidate peptides were identified using a new screening procedure based on physicochemical criteria to reveal matching peptides within protein databases. Fifteen such peptides, along with a range of natural antimicrobial peptides, were examined using DSC and CD to characterize their interaction with phospholipid membranes. Principal component analysis of DSC data shows that the investigated peptides group according to their effects on the main phase transition of phospholipid vesicles, and that these effects correlate both to antimicrobial activity and to the changes in peptide secondary structure. Consequently, we have been able to identify novel antimicrobial peptides from larger proteins not hitherto associated with such activity, mimicking endogenous and/or exogenous microorganism enzymatic processing of parent proteins to smaller bioactive molecules. A biotechnological application for this methodology is explored. Soybean (Glycine max) plants, transformed to include a putative antimicrobial protein fragment encoded in its own genome were tested for tolerance against Phakopsora pachyrhizi, the causative agent of the Asian soybean rust. This procedure may represent an inventive alternative to the transgenic technology, since the genetic material to be used belongs to the host organism and not to exogenous sources.

  15. Is this Red Spot the Blue Spot (locus ceruleum)?

    Energy Technology Data Exchange (ETDEWEB)

    Choe, Won Sick; Lee, Yu Kyung; Lee, Min Kyung; Hwang, Kyung Hoon [Gachon University Gil Hospital, Incheon (Korea, Republic of)

    2010-06-15

    The authors report brain images of 18F-FDG-PET in a case of schizophrenia. The images showed strikingly increased bilateral uptake in the locus ceruleum. The locus ceruleum is called the blue spot and known to be a center of the norepinephrinergic system.

  16. A symmetric image encryption scheme based on 3D chaotic cat maps

    International Nuclear Information System (INIS)

    Chen Guanrong; Mao Yaobin; Chui, Charles K.

    2004-01-01

    Encryption of images is different from that of texts due to some intrinsic features of images such as bulk data capacity and high redundancy, which are generally difficult to handle by traditional methods. Due to the exceptionally desirable properties of mixing and sensitivity to initial conditions and parameters of chaotic maps, chaos-based encryption has suggested a new and efficient way to deal with the intractable problem of fast and highly secure image encryption. In this paper, the two-dimensional chaotic cat map is generalized to 3D for designing a real-time secure symmetric encryption scheme. This new scheme employs the 3D cat map to shuffle the positions (and, if desired, grey values as well) of image pixels and uses another chaotic map to confuse the relationship between the cipher-image and the plain-image, thereby significantly increasing the resistance to statistical and differential attacks. Thorough experimental tests are carried out with detailed analysis, demonstrating the high security and fast encryption speed of the new scheme

  17. Single-channel color image encryption based on iterative fractional Fourier transform and chaos

    Science.gov (United States)

    Sui, Liansheng; Gao, Bo

    2013-06-01

    A single-channel color image encryption is proposed based on iterative fractional Fourier transform and two-coupled logistic map. Firstly, a gray scale image is constituted with three channels of the color image, and permuted by a sequence of chaotic pairs which is generated by two-coupled logistic map. Firstly, the permutation image is decomposed into three components again. Secondly, the first two components are encrypted into a single one based on iterative fractional Fourier transform. Similarly, the interim image and third component are encrypted into the final gray scale ciphertext with stationary white noise distribution, which has camouflage property to some extent. In the process of encryption and description, chaotic permutation makes the resulting image nonlinear and disorder both in spatial domain and frequency domain, and the proposed iterative fractional Fourier transform algorithm has faster convergent speed. Additionally, the encryption scheme enlarges the key space of the cryptosystem. Simulation results and security analysis verify the feasibility and effectiveness of this method.

  18. An image encryption scheme based on three-dimensional Brownian motion and chaotic system

    International Nuclear Information System (INIS)

    Chai Xiu-Li; Yuan Ke; Gan Zhi-Hua; Lu Yang; Chen Yi-Ran

    2017-01-01

    At present, many chaos-based image encryption algorithms have proved to be unsafe, few encryption schemes permute the plain images as three-dimensional (3D) bit matrices, and thus bits cannot move to any position, the movement range of bits are limited, and based on them, in this paper we present a novel image encryption algorithm based on 3D Brownian motion and chaotic systems. The architecture of confusion and diffusion is adopted. Firstly, the plain image is converted into a 3D bit matrix and split into sub blocks. Secondly, block confusion based on 3D Brownian motion (BCB3DBM) is proposed to permute the position of the bits within the sub blocks, and the direction of particle movement is generated by logistic-tent system (LTS). Furthermore, block confusion based on position sequence group (BCBPSG) is introduced, a four-order memristive chaotic system is utilized to give random chaotic sequences, and the chaotic sequences are sorted and a position sequence group is chosen based on the plain image, then the sub blocks are confused. The proposed confusion strategy can change the positions of the bits and modify their weights, and effectively improve the statistical performance of the algorithm. Finally, a pixel level confusion is employed to enhance the encryption effect. The initial values and parameters of chaotic systems are produced by the SHA 256 hash function of the plain image. Simulation results and security analyses illustrate that our algorithm has excellent encryption performance in terms of security and speed. (paper)

  19. Using wavefront coding technique as an optical encryption system: reliability analysis and vulnerabilities assessment

    Science.gov (United States)

    Konnik, Mikhail V.

    2012-04-01

    Wavefront coding paradigm can be used not only for compensation of aberrations and depth-of-field improvement but also for an optical encryption. An optical convolution of the image with the PSF occurs when a diffractive optical element (DOE) with a known point spread function (PSF) is placed in the optical path. In this case, an optically encoded image is registered instead of the true image. Decoding of the registered image can be performed using standard digital deconvolution methods. In such class of optical-digital systems, the PSF of the DOE is used as an encryption key. Therefore, a reliability and cryptographic resistance of such an encryption method depends on the size and complexity of the PSF used for optical encoding. This paper gives a preliminary analysis on reliability and possible vulnerabilities of such an encryption method. Experimental results on brute-force attack on the optically encrypted images are presented. Reliability estimation of optical coding based on wavefront coding paradigm is evaluated. An analysis of possible vulnerabilities is provided.

  20. Image encryption based on fractal-structured phase mask in fractional Fourier transform domain

    Science.gov (United States)

    Zhao, Meng-Dan; Gao, Xu-Zhen; Pan, Yue; Zhang, Guan-Lin; Tu, Chenghou; Li, Yongnan; Wang, Hui-Tian

    2018-04-01

    We present an optical encryption approach based on the combination of fractal Fresnel lens (FFL) and fractional Fourier transform (FrFT). Our encryption approach is in fact a four-fold encryption scheme, including the random phase encoding produced by the Gerchberg–Saxton algorithm, a FFL, and two FrFTs. A FFL is composed of a Sierpinski carpet fractal plate and a Fresnel zone plate. In our encryption approach, the security is enhanced due to the more expandable key spaces and the use of FFL overcomes the alignment problem of the optical axis in optical system. Only using the perfectly matched parameters of the FFL and the FrFT, the plaintext can be recovered well. We present an image encryption algorithm that from the ciphertext we can get two original images by the FrFT with two different phase distribution keys, obtained by performing 100 iterations between the two plaintext and ciphertext, respectively. We test the sensitivity of our approach to various parameters such as the wavelength of light, the focal length of FFL, and the fractional orders of FrFT. Our approach can resist various attacks.

  1. Optical Image Encryption Using Devil’s Vortex Toroidal Lens in the Fresnel Transform Domain

    Directory of Open Access Journals (Sweden)

    Hukum Singh

    2015-01-01

    Full Text Available We have carried out a study of optical image encryption in the Fresnel transform (FrT domain, using a random phase mask (RPM in the input plane and a phase mask based on devil’s vortex toroidal lens (DVTL in the frequency plane. The original images are recovered from their corresponding encrypted images by using the correct parameters of the FrT and the parameters of DVTL. The use of a DVTL-based structured mask enhances security by increasing the key space for encryption and also aids in overcoming the problem of axis alignment associated with an optical setup. The proposed encryption scheme is a lensless optical system and its digital implementation has been performed using MATLAB 7.6.0 (R2008a. The scheme has been validated for a grayscale and a binary image. The efficacy of the proposed scheme is verified by computing mean-squared-error (MSE between the recovered and the original images. We have also investigated the scheme’s sensitivity to the encryption parameters and examined its robustness against occlusion and noise attacks.

  2. Simultaneous compression and encryption for secure real-time secure transmission of sensitive video transmission

    Science.gov (United States)

    Al-Hayani, Nazar; Al-Jawad, Naseer; Jassim, Sabah A.

    2014-05-01

    Video compression and encryption became very essential in a secured real time video transmission. Applying both techniques simultaneously is one of the challenges where the size and the quality are important in multimedia transmission. In this paper we proposed a new technique for video compression and encryption. Both encryption and compression are based on edges extracted from the high frequency sub-bands of wavelet decomposition. The compression algorithm based on hybrid of: discrete wavelet transforms, discrete cosine transform, vector quantization, wavelet based edge detection, and phase sensing. The compression encoding algorithm treats the video reference and non-reference frames in two different ways. The encryption algorithm utilized A5 cipher combined with chaotic logistic map to encrypt the significant parameters and wavelet coefficients. Both algorithms can be applied simultaneously after applying the discrete wavelet transform on each individual frame. Experimental results show that the proposed algorithms have the following features: high compression, acceptable quality, and resistance to the statistical and bruteforce attack with low computational processing.

  3. Influence of a perturbation in the Gyrator domain for a joint transform correlator-based encryption system

    Science.gov (United States)

    Vilardy, Juan M.; Millán, María. S.; Pérez-Cabré, Elisabet

    2017-08-01

    We present the results of the noise and occlusion tests in the Gyrator domain (GD) for a joint transform correlator-based encryption system. This encryption system was recently proposed and it was implemented by using a fully phase nonzero-order joint transform correlator (JTC) and the Gyrator transform (GT). The decryption system was based on two successive GTs. In this paper, we make several numerical simulations in order to test the performance and robustness of the JTC-based encryption-decryption system in the GD when the encrypted image is corrupted by noise or occlusion. The encrypted image is affected by additive and multiplicative noise. We also test the effect of data loss due to partial occlusion of the encrypted information. Finally, we evaluate the performance and robustness of the encryption-decryption system in the GD by using the metric of the root mean square error (RMSE) between the original image and the decrypted image when the encrypted image is degraded by noise or modified by occlusion.

  4. Asymmetric double-image encryption method by using iterative phase retrieval algorithm in fractional Fourier transform domain

    Science.gov (United States)

    Sui, Liansheng; Lu, Haiwei; Ning, Xiaojuan; Wang, Yinghui

    2014-02-01

    A double-image encryption scheme is proposed based on an asymmetric technique, in which the encryption and decryption processes are different and the encryption keys are not identical to the decryption ones. First, a phase-only function (POF) of each plain image is retrieved by using an iterative process and then encoded into an interim matrix. Two interim matrices are directly modulated into a complex image by using the convolution operation in the fractional Fourier transform (FrFT) domain. Second, the complex image is encrypted into the gray scale ciphertext with stationary white-noise distribution by using the FrFT. In the encryption process, three random phase functions are used as encryption keys to retrieve the POFs of plain images. Simultaneously, two decryption keys are generated in the encryption process, which make the optical implementation of the decryption process convenient and efficient. The proposed encryption scheme has high robustness to various attacks, such as brute-force attack, known plaintext attack, cipher-only attack, and specific attack. Numerical simulations demonstrate the validity and security of the proposed method.

  5. Combination of a micro-lens multi-spot generator with a galvanometer scanner for flexible parallel micromachining of silicon

    Science.gov (United States)

    Zimmermann, Maik; Schmidt, Michael

    2011-10-01

    Multi focus optics are used for parallelizing production and for large-scale material processing. These elements split the beam into a periodic spot pattern with a defined grid and spot size. The challenge lies in the generation of a homogeneous envelope. Additionally the demand for flexible systems for an in-process changing of optical properties increases. Different components for multi spot generation like diffractive optical elements or micro lens arrays have been investigated. Diffractive optical elements offer large degree of freedom in the generation of arbitrary intensity distributions. In the paper we demonstrate the use of a diffractive element in combination with a multi spot generator. Within the paper we present the investigation of a micro lens array in a fly's eye condenser setup for the generation of homogeneous spot patterns. The multi spot generator is combined with a galvanometer scanner for forming an arbitrary shaped laser beam into a spot-, ring or arbitrary array pattern. We show the principal functionality of the multi-spot generator. Furthermore constrains of this setup are demonstrated. The multi spot scanner is used for micro structuring of silicon with a nanosecond diode pumped solid state laser. The ablation rate and structure quality are compared to single spot processing.

  6. Practical Architectures for Deployment of Searchable Encryption in a Cloud Environment

    Directory of Open Access Journals (Sweden)

    Sarah Louise Renwick

    2017-11-01

    Full Text Available Public cloud service providers provide an infrastructure that gives businesses and individuals access to computing power and storage space on a pay-as-you-go basis. This allows these entities to bypass the usual costs associated with having their own data centre such as: hardware, construction, air conditioning and security costs, for example, making this a cost-effective solution for data storage. If the data being stored is of a sensitive nature, encrypting it prior to outsourcing it to a public cloud is a good method of ensuring the confidentiality of the data. With the data being encrypted, however, searching over it becomes unfeasible. In this paper, we examine different architectures for supporting search over encrypted data and discuss some of the challenges that need to be overcome if these techniques are to be engineered into practical systems.

  7. Efficient and side-channel resistant authenticated encryption of FPGA bitstreams

    DEFF Research Database (Denmark)

    Bogdanov, Andrey; Moradi, Amir; Yalcin, Tolga

    2013-01-01

    State-of-the-art solutions for FPGA bitstream protection rely on encryption and authentication of the bitstream to both ensure its confidentiality, thwarting unauthorized copying and reverse engineering, and prevent its unauthorized modification, maintaining a root of trust in the field. Adequate...... protection of the FPGA bitstream is of paramount importance to sustain the central functionality of dynamic reconfiguration in a hostile environment. In this work, we propose a new solution for authenticated encryption (AE) tailored for FPGA bitstream protection. It is based on the recent proposal presented...... AE modes of operation with the same countermeasure. We conclude that the deployment of dedicated AE schemes such as ALE significantly facilitates the real-world efficiency and security of FPGA bitstream protection in practice: Not only our solution enables authenticated encryption for bitstream...

  8. P-Code-Enhanced Encryption-Mode Processing of GPS Signals

    Science.gov (United States)

    Young, Lawrence; Meehan, Thomas; Thomas, Jess B.

    2003-01-01

    A method of processing signals in a Global Positioning System (GPS) receiver has been invented to enable the receiver to recover some of the information that is otherwise lost when GPS signals are encrypted at the transmitters. The need for this method arises because, at the option of the military, precision GPS code (P-code) is sometimes encrypted by a secret binary code, denoted the A code. Authorized users can recover the full signal with knowledge of the A-code. However, even in the absence of knowledge of the A-code, one can track the encrypted signal by use of an estimate of the A-code. The present invention is a method of making and using such an estimate. In comparison with prior such methods, this method makes it possible to recover more of the lost information and obtain greater accuracy.

  9. Privacy authentication using key attribute-based encryption in mobile cloud computing

    Science.gov (United States)

    Mohan Kumar, M.; Vijayan, R.

    2017-11-01

    Mobile Cloud Computing is becoming more popular in nowadays were users of smartphones are getting increased. So, the security level of cloud computing as to be increased. Privacy Authentication using key-attribute based encryption helps the users for business development were the data sharing with the organization using the cloud in a secured manner. In Privacy Authentication the sender of data will have permission to add their receivers to whom the data access provided for others the access denied. In sender application, the user can choose the file which is to be sent to receivers and then that data will be encrypted using Key-attribute based encryption using AES algorithm. In which cipher created, and that stored in Amazon Cloud along with key value and the receiver list.

  10. Optical information encryption based on incoherent superposition with the help of the QR code

    Science.gov (United States)

    Qin, Yi; Gong, Qiong

    2014-01-01

    In this paper, a novel optical information encryption approach is proposed with the help of QR code. This method is based on the concept of incoherent superposition which we introduce for the first time. The information to be encrypted is first transformed into the corresponding QR code, and thereafter the QR code is further encrypted into two phase only masks analytically by use of the intensity superposition of two diffraction wave fields. The proposed method has several advantages over the previous interference-based method, such as a higher security level, a better robustness against noise attack, a more relaxed work condition, and so on. Numerical simulation results and actual smartphone collected results are shown to validate our proposal.

  11. Single Channel Quantum Color Image Encryption Algorithm Based on HSI Model and Quantum Fourier Transform

    Science.gov (United States)

    Gong, Li-Hua; He, Xiang-Tao; Tan, Ru-Chao; Zhou, Zhi-Hong

    2018-01-01

    In order to obtain high-quality color images, it is important to keep the hue component unchanged while emphasize the intensity or saturation component. As a public color model, Hue-Saturation Intensity (HSI) model is commonly used in image processing. A new single channel quantum color image encryption algorithm based on HSI model and quantum Fourier transform (QFT) is investigated, where the color components of the original color image are converted to HSI and the logistic map is employed to diffuse the relationship of pixels in color components. Subsequently, quantum Fourier transform is exploited to fulfill the encryption. The cipher-text is a combination of a gray image and a phase matrix. Simulations and theoretical analyses demonstrate that the proposed single channel quantum color image encryption scheme based on the HSI model and quantum Fourier transform is secure and effective.

  12. Chaos based video encryption using maps and Ikeda time delay system

    Science.gov (United States)

    Valli, D.; Ganesan, K.

    2017-12-01

    Chaos based cryptosystems are an efficient method to deal with improved speed and highly secured multimedia encryption because of its elegant features, such as randomness, mixing, ergodicity, sensitivity to initial conditions and control parameters. In this paper, two chaos based cryptosystems are proposed: one is the higher-dimensional 12D chaotic map and the other is based on the Ikeda delay differential equation (DDE) suitable for designing a real-time secure symmetric video encryption scheme. These encryption schemes employ a substitution box (S-box) to diffuse the relationship between pixels of plain video and cipher video along with the diffusion of current input pixel with the previous cipher pixel, called cipher block chaining (CBC). The proposed method enhances the robustness against statistical, differential and chosen/known plain text attacks. Detailed analysis is carried out in this paper to demonstrate the security and uniqueness of the proposed scheme.

  13. Quantum image encryption based on generalized affine transform and logistic map

    Science.gov (United States)

    Liang, Hao-Ran; Tao, Xiang-Yang; Zhou, Nan-Run

    2016-07-01

    Quantum circuits of the generalized affine transform are devised based on the novel enhanced quantum representation of digital images. A novel quantum image encryption algorithm combining the generalized affine transform with logistic map is suggested. The gray-level information of the quantum image is encrypted by the XOR operation with a key generator controlled by the logistic map, while the position information of the quantum image is encoded by the generalized affine transform. The encryption keys include the independent control parameters used in the generalized affine transform and the logistic map. Thus, the key space is large enough to frustrate the possible brute-force attack. Numerical simulations and analyses indicate that the proposed algorithm is realizable, robust and has a better performance than its classical counterpart in terms of computational complexity.

  14. 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.

  15. A fast image encryption system based on chaotic maps with finite precision representation

    International Nuclear Information System (INIS)

    Kwok, H.S.; Tang, Wallace K.S.

    2007-01-01

    In this paper, a fast chaos-based image encryption system with stream cipher structure is proposed. In order to achieve a fast throughput and facilitate hardware realization, 32-bit precision representation with fixed point arithmetic is assumed. The major core of the encryption system is a pseudo-random keystream generator based on a cascade of chaotic maps, serving the purpose of sequence generation and random mixing. Unlike the other existing chaos-based pseudo-random number generators, the proposed keystream generator not only achieves a very fast throughput, but also passes the statistical tests of up-to-date test suite even under quantization. The overall design of the image encryption system is to be explained while detail cryptanalysis is given and compared with some existing schemes

  16. Multi-image encryption based on synchronization of chaotic lasers and iris authentication

    Science.gov (United States)

    Banerjee, Santo; Mukhopadhyay, Sumona; Rondoni, Lamberto

    2012-07-01

    A new technique of transmitting encrypted combinations of gray scaled and chromatic images using chaotic lasers derived from Maxwell-Bloch's equations has been proposed. This novel scheme utilizes the general method of solution of a set of linear equations to transmit similar sized heterogeneous images which are a combination of monochrome and chromatic images. The chaos encrypted gray scaled images are concatenated along the three color planes resulting in color images. These are then transmitted over a secure channel along with a cover image which is an iris scan. The entire cryptology is augmented with an iris-based authentication scheme. The secret messages are retrieved once the authentication is successful. The objective of our work is briefly outlined as (a) the biometric information is the iris which is encrypted before transmission, (b) the iris is used for personal identification and verifying for message integrity, (c) the information is transmitted securely which are colored images resulting from a combination of gray images, (d) each of the images transmitted are encrypted through chaos based cryptography, (e) these encrypted multiple images are then coupled with the iris through linear combination of images before being communicated over the network. The several layers of encryption together with the ergodicity and randomness of chaos render enough confusion and diffusion properties which guarantee a fool-proof approach in achieving secure communication as demonstrated by exhaustive statistical methods. The result is vital from the perspective of opening a fundamental new dimension in multiplexing and simultaneous transmission of several monochromatic and chromatic images along with biometry based authentication and cryptography.

  17. Dressing percentage in Romanian spotted breed

    Directory of Open Access Journals (Sweden)

    eleonora nistor

    2013-05-01

    Full Text Available The purpose of this research was to determine whether there are significant differences in terms of carcass weight, forequarters, hindquarters and the dressing percentage among Romanian Spotted breed steers and first generation crossbreed obtained between Romanian Spotted and Holstein at slaughter age of 12 and 17 months respectively. Study was done on Romanian Spotted breed steer aged 12 months (36 heads and 17 months (19 heads; Romanian Spotted x Holstein first generation crossbreed of aged 12 months (29 heads and 17 months (20 heads. The Romanian Spotted breed steer, show superiority in terms of carcass weight compared to crossbreed of Romanian Spotted x Holstein, therefore this breed has a better suitability for fattening for meat. Regarding dressing percentage is higher in crossbreed of Romanian Spotted x Holstein compared with Romanian Spotted breed steers, but the difference is insignificant.

  18. An encryption scheme based on phase-shifting digital holography and amplitude-phase disturbance

    International Nuclear Information System (INIS)

    Hua Li-Li; Xu Ning; Yang Geng

    2014-01-01

    In this paper, we propose an encryption scheme based on phase-shifting digital interferometry. According to the original system framework, we add a random amplitude mask and replace the Fourier transform by the Fresnel transform. We develop a mathematical model and give a discrete formula based on the scheme, which makes it easy to implement the scheme in computer programming. The experimental results show that the improved system has a better performance in security than the original encryption method. Moreover, it demonstrates a good capability of anti-noise and anti-shear robustness

  19. Applying transpose matrix on advanced encryption standard (AES) for database content

    Science.gov (United States)

    Manurung, E. B. P.; Sitompul, O. S.; Suherman

    2018-03-01

    Advanced Encryption Standard (AES) is a specification for the encryption of electronic data established by the U.S. National Institute of Standards and Technology (NIST) and has been adopted by the U.S. government and is now used worldwide. This paper reports the impact of transpose matrix integration to AES. Transpose matrix implementation on AES is aimed at first stage of chypertext modifications for text based database security so that the confidentiality improves. The matrix is also able to increase the avalanche effect of the cryptography algorithm 4% in average.

  20. Optical image encryption in the fractional Hartley domain, using Arnold transform and singular value decomposition

    Science.gov (United States)

    Singh, Phool; Yadav, A. K.; Singh, Kehar; Saini, Indu

    2017-01-01

    A new scheme for image encryption is proposed, using fractional Hartley transform followed by Arnold transform and singular value decomposition in the frequency domain. As the plaintext is an amplitude image, the mask used in the spatial domain is a random phase mask (RPM). The proposed scheme has been validated for grayscale images and is sensitive to the encryption parameters such as order of Arnold transform and fractional orders of the Hartley transform. We have also evaluated the scheme's resistance to the well-known noise and occlusions attacks.

  1. Phase image encryption in the fractional Hartley domain using Arnold transform and singular value decomposition

    Science.gov (United States)

    Singh, Phool; Yadav, A. K.; Singh, Kehar

    2017-04-01

    A novel scheme for image encryption of phase images is proposed, using fractional Hartley transform followed by Arnold transform and singular value decomposition in the frequency domain. Since the plaintext is a phase image, the mask used in the spatial domain is a random amplitude mask. The proposed scheme has been validated for grayscale images and is sensitive to the encryption parameters such as the order of the Arnold transform and the fractional orders of the Hartley transform. We have also evaluated the scheme's resistance to the well-known noise and occlusion attacks.

  2. Vulnerability issues on research in WLAN encryption algorithms WEP WPA/WPA2 Personal

    International Nuclear Information System (INIS)

    Ioannis, Lazaridis; Sotirios, Pouros; Simeon, Veloudis

    2013-01-01

    This paper presents historic and new evidence that wireless encryption algorithms can be cracked or even bypassed which has been proved by other researchers. The paper presents a description of how WEP and WPA/WPA2 Personal encrypt data and how the passphrase is shared between the nodes of the network. Modern tools available on the internet have been evaluated, decomposed and tested to provide evidence on the reliability of passwords. A number of criteria are used to compare the tools and their efficiency

  3. Optical image encryption based on phase retrieval combined with three-dimensional particle-like distribution

    International Nuclear Information System (INIS)

    Chen, Wen; Chen, Xudong; Sheppard, Colin J R

    2012-01-01

    We propose a new phase retrieval algorithm for optical image encryption in three-dimensional (3D) space. The two-dimensional (2D) plaintext is considered as a series of particles distributed in 3D space, and an iterative phase retrieval algorithm is developed to encrypt the series of particles into phase-only masks. The feasibility and effectiveness of the proposed method are demonstrated by a numerical experiment, and the advantages and security of the proposed optical cryptosystems are also analyzed and discussed. (paper)

  4. Audio signal encryption using chaotic Hénon map and lifting wavelet transforms

    Science.gov (United States)

    Roy, Animesh; Misra, A. P.

    2017-12-01

    We propose an audio signal encryption scheme based on the chaotic Hénon map. The scheme mainly comprises two phases: one is the preprocessing stage where the audio signal is transformed into data by the lifting wavelet scheme and the other in which the transformed data is encrypted by chaotic data set and hyperbolic functions. Furthermore, we use dynamic keys and consider the key space size to be large enough to resist any kind of cryptographic attacks. A statistical investigation is also made to test the security and the efficiency of the proposed scheme.

  5. On the Security of the CCM Encryption Mode and of a Slight Variant

    OpenAIRE

    Fouque, Pierre-Alain; Martinet, Gwenaëlle; Valette, Frédéric; Zimmer, Sebastien

    2008-01-01

    The original publication is available at www.springerlink.com; International audience; In this paper, we present an analysis of the CCM mode of operations and of a slight variant. CCM is a simple and efficient encryption scheme which combines a CBC-MAC authentication scheme with the counter mode of encryption. It is used in several standards. Despite some criticisms (mainly this mode is not online, and requires non-repeating nonces), it has nice features that make it worth to study. One impor...

  6. Cryptographic salting for security enhancement of double random phase encryption schemes

    Science.gov (United States)

    Velez Zea, Alejandro; Fredy Barrera, John; Torroba, Roberto

    2017-10-01

    Security in optical encryption techniques is a subject of great importance, especially in light of recent reports of successful attacks. We propose a new procedure to reinforce the ciphertexts generated in double random phase encrypting experimental setups. This ciphertext is protected by multiplexing with a ‘salt’ ciphertext coded with the same setup. We present an experimental implementation of the ‘salting’ technique. Thereafter, we analyze the resistance of the ‘salted’ ciphertext under some of the commonly known attacks reported in the literature, demonstrating the validity of our proposal.

  7. Supervised Multi-Authority Scheme with Blind Signature for IoT with Attribute Based Encryption

    Science.gov (United States)

    Nissenbaum, O. V.; Ponomarov, K. Y.; Zaharov, A. A.

    2018-04-01

    This article proposes a three-side cryptographic scheme for verifying device attributes with a Supervisor and a Certification Authority (CA) for attribute-based encryption. Two options are suggested: using a message authentication code and using a digital signature. The first version is suitable for networks with one CA, and the second one for networks with several CAs, including dynamic systems. Also, the addition of this scheme with a blind signature is proposed to preserve the confidentiality of the device attributes from the CA. The introduction gives a definition and a brief historical overview of attribute-based encryption (ABE), addresses the use of ABE in the Internet of Things.

  8. An Elgamal Encryption Scheme of Fibonacci Q-Matrix and Finite State Machine

    Directory of Open Access Journals (Sweden)

    B. Ravi Kumar

    2015-12-01

    Full Text Available Cryptography is the science of writing messages in unknown form using mathematical models. In Cryptography, several ciphers were introduced for the encryption schemes. Recent research focusing on designing various mathematical models in such a way that tracing the inverse of the designed mathematical models is infeasible for the eve droppers. In the present work, the ELGamal encryption scheme is executed using the generator of a cyclic group formed by the points on choosing elliptic curve, finite state machines and key matrices obtained from the Fibonacci sequences.

  9. A secure approach for encrypting and compressing biometric information employing orthogonal code and steganography

    Science.gov (United States)

    Islam, Muhammad F.; Islam, Mohammed N.

    2012-04-01

    The objective of this paper is to develop a novel approach for encryption and compression of biometric information utilizing orthogonal coding and steganography techniques. Multiple biometric signatures are encrypted individually using orthogonal codes and then multiplexed together to form a single image, which is then embedded in a cover image using the proposed steganography technique. The proposed technique employs three least significant bits for this purpose and a secret key is developed to choose one from among these bits to be replaced by the corresponding bit of the biometric image. The proposed technique offers secure transmission of multiple biometric signatures in an identification document which will be protected from unauthorized steganalysis attempt.

  10. Dominant white spotting in the Chinese hamster.

    Science.gov (United States)

    Henwood, C; Henwood, J; Robinson, R

    1987-01-01

    An autosomal dominant white spotting mutant is described for the Chinese hamster. The mutant gene is designated as dominant spot (symbol Ds). The homozygote DsDs is a prenatal lethal while the heterozygote Ds + displays white spotting. The expression of white is variable, ranging from a white forehead spot to extensive white on the body. The venter is invariably white. Growth appears to be normal and the fertility of both sizes shows no impairment.

  11. Laser Pyrometer For Spot Temperature Measurements

    Science.gov (United States)

    Elleman, D. D.; Allen, J. L.; Lee, M. C.

    1988-01-01

    Laser pyrometer makes temperature map by scanning measuring spot across target. Scanning laser pyrometer passively measures radiation emitted by scanned spot on target and calibrated by similar passive measurement on blackbody of known temperature. Laser beam turned on for active measurements of reflectances of target spot and reflectance standard. From measurements, temperature of target spot inferred. Pyrometer useful for non-contact measurement of temperature distributions in processing of materials.

  12. A Drosophila wing spot test

    International Nuclear Information System (INIS)

    Ayaki, Toshikazu; Yoshikawa, Isao; Niikawa, Norio; Hoshi, Masaharu.

    1986-01-01

    A Drosophila wing spot test system was used to investigate the effects of low doses of X-rays, gamma rays, and both 2.3 and 14.1 MeV neutrons on somatic chromosome mutation (SCM) induction. The incidence of SCM was significantly increased with any type of radiation, with evident linear dose-response relationship within the range of 3 to 20 cGy. It was estimated that relative biological effectiveness value for SCM induction of 2.3 MeV neutrons to X-rays and gamma rays is much higher than that of 14.1 MeV neutrons to those photons (2.4 vs 8.0). The Drosophila wing spot test system seems to become a promising in vivo experimental method for higher animals in terms of the lack of necessity for a marvelously large number of materials required in conventional test system. (Namekawa, K.)

  13. Sweet Spots and Door Stops

    Science.gov (United States)

    Thompson, Michael; Tsui, Stella; Leung, Chi Fan

    2011-01-01

    A sweet spot is referred to in sport as the perfect place to strike a ball with a racquet or bat. It is the point of contact between bat and ball where maximum results can be produced with minimal effort from the hand of the player. Similar physics can be applied to the less inspiring examples of door stops; the perfect position of a door stop is…

  14. Justifications shape ethical blind spots.

    Science.gov (United States)

    Pittarello, Andrea; Leib, Margarita; Gordon-Hecker, Tom; Shalvi, Shaul

    2015-06-01

    To some extent, unethical behavior results from people's limited attention to ethical considerations, which results in an ethical blind spot. Here, we focus on the role of ambiguity in shaping people's ethical blind spots, which in turn lead to their ethical failures. We suggest that in ambiguous settings, individuals' attention shifts toward tempting information, which determines the magnitude of their lies. Employing a novel ambiguous-dice paradigm, we asked participants to report the outcome of the die roll appearing closest to the location of a previously presented fixation cross on a computer screen; this outcome would determine their pay. We varied the value of the die second closest to the fixation cross to be either higher (i.e., tempting) or lower (i.e., not tempting) than the die closest to the fixation cross. Results of two experiments revealed that in ambiguous settings, people's incorrect responses were self-serving. Tracking participants' eye movements demonstrated that people's ethical blind spots are shaped by increased attention toward tempting information. © The Author(s) 2015.

  15. Resistance Spot Welding of dissimilar Steels

    Directory of Open Access Journals (Sweden)

    Ladislav Kolařík

    2012-01-01

    Full Text Available This paper presents an analysis of the properties of resistance spot welds between low carbon steel and austenitic CrNi stainless steel. The thickness of the welded dissimilar materials was 2 mm. A DeltaSpot welding gun with a process tape was used for welding the dissimilar steels. Resistance spot welds were produced with various welding parameters (welding currents ranging from 7 to 8 kA. Light microscopy, microhardness measurements across the welded joints, and EDX analysis were used to evaluate the quality of the resistance spot welds. The results confirm the applicability of DeltaSpot welding for this combination of materials.

  16. Variability of Jupiter's Five-Micron Hot Spot Inventory

    Science.gov (United States)

    Yanamandra-Fisher, Padma A.; Orton, G. S.; Wakefield, L.; Rogers, J. H.; Simon-Miller, A. A.; Boydstun, K.

    2012-01-01

    Global upheavals on Jupiter involve changes in the albedo of entire axisymmetric regions, lasting several years, with the last two occurring in 1989 and 2006. Against this backdrop of planetary-scale changes, discrete features such as the Great Red Spot (GRS), and other vortices exhibit changes on shorter spatial- and time-scales. We track the variability of the discrete equatorial 5-micron hot spots, semi-evenly spaced in longitude and confined to a narrow latitude band centered at 6.5degN (southern edge of the North Equatorial Belt, NEB), abundant in Voyager images. Tantalizingly similar patterns were observed in the visible (bright plumes and blue-gray regions), where reflectivity in the red is anti-correlated with 5-microns thermal radiance. Ortiz et al. (1998, GRL, 103) characterized the latitude and drift rates of the hot spots, including the descent of the Galileo probe at the southern edge of a 5-micron hot spot, as the superposition of equatorial Rossby waves, with phase speeds between 99 - 103m/s, relative to System III. We note that the high 5-micron radiances correlate well but not perfectly with high 8.57-micron radiances. Because the latter are modulated primarily by changes in the upper ammonia (NH3) ice cloud opacity, this correlation implies that changes in the ammonia ice cloud field may be responsible for the variability seen in the 5-m maps. During the NEB fade (2011 - early 2012), however, these otherwise ubiquitous features were absent, an atmospheric state not seen in decades. The ongoing NEB revival indicates nascent 5-m hot spots as early as April 2012, with corresponding visible dark spots. Their continuing growth through July 2012 indicates the possit.le re-establishment of Rossby waves. The South Equatorial Belt (SEB) and NEB revivals began similarly with an instability that developed into a major outbreak, and many similarities in the observed propagation of clear regions.

  17. ESA uncovers Geminga's `hot spot'

    Science.gov (United States)

    2004-07-01

    16 July 2004 Astronomers using ESA’s X-ray observatory XMM-Newton have detected a small, bright ‘hot spot’ on the surface of the neutron star called Geminga, 500 light-years away. The hot spot is the size of a football field and is caused by the same mechanism producing Geminga’s X-ray tails. This discovery identifies the missing link between the X-ray and gamma-ray emission from Geminga. hi-res Size hi-res: 1284 kb Credits: ESA, P. Caraveo (IASF, Milan) Geminga's hot spot This figure shows the effects of charged particles accelerated in the magnetosphere of Geminga. Panel (a) shows an image taken with the EPIC instrument on board the XMM-Newton observatory. The bright tails, made of particles kicked out by Geminga’s strong magnetic field, trail the neutron star as it moves about in space. Panel (b) shows how electrically charged particles interact with Geminga’s magnetic field. For example, if electrons (blue) are kicked out by the star, positrons (in red) hit the star’s magnetic poles like in an ‘own goal’. Panel (c) illustrates the size of Geminga’s magnetic field (blue) compared to that of the star itself at the centre (purple). The magnetic field is tilted with respect to Geminga’s rotation axis (red). Panel (d) shows the magnetic poles of Geminga, where charged particles hit the surface of the star, creating a two-million degrees hot spot, a region much hotter than the surroundings. As the star spins on its rotation axis, the hot spot comes into view and then disappears, causing the periodic colour change seen by XMM-Newton. An animated version of the entire sequence can be found at: Click here for animated GIF [low resolution, animated GIF, 5536 KB] Click here for AVI [high resolution, AVI with DIVX compression, 19128 KB] hi-res Size hi-res: 371 kb Credits: ESA, P. Caraveo (IASF, Milan) Geminga's hot spot, panel (a) Panel (a) shows an image taken with the EPIC instrument on board the XMM-Newton observatory. The bright tails, made of

  18. A Secure Ciphertext Self-Destruction Scheme with Attribute-Based Encryption

    Directory of Open Access Journals (Sweden)

    Tonghao Yang

    2015-01-01

    Full Text Available The secure destruction of expired data is one of the important contents in the research of cloud storage security. Applying the attribute-based encryption (ABE and the distributed hash table (DHT technology to the process of data destruction, we propose a secure ciphertext self-destruction scheme with attribute-based encryption called SCSD. In SCSD scheme, the sensitive data is first encrypted under an access key and then the ciphertext shares are stored in the DHT network along with the attribute shares. Meanwhile, the rest of the sensitive data ciphertext and the shares of access key ciphertext constitute the encapsulated self-destruction object (EDO, which is stored in the cloud. When the sensitive data is expired, the nodes in DHT networks can automatically discard the ciphertext shares and the attribute shares, which can make the ciphertext and the access key unrecoverable. Thus, we realize secure ciphertext self-destruction. Compared with the current schemes, our SCSD scheme not only can support efficient data encryption and fine-grained access control in lifetime and secure self-destruction after expiry, but also can resist the traditional cryptanalysis attack as well as the Sybil attack in the DHT network.

  19. 76 FR 1059 - Publicly Available Mass Market Encryption Software and Other Specified Publicly Available...

    Science.gov (United States)

    2011-01-07

    ... available'' mass market encryption object code software with a symmetric key length greater than 64-bits... a simplification of the regulatory provisions for publicly available mass market software and... the EAR). At that time, much less mass market software was ``publicly available'' than is the case...

  20. Anonymous Multi-Receiver Identity-Based Authenticated Encryption with CCA Security

    Directory of Open Access Journals (Sweden)

    Chun-I Fan

    2015-10-01

    Full Text Available In a multi-receiver encryption system, a sender chooses a set of authorized receivers and sends them a message securely and efficiently, as the message is well encrypted and only one ciphertext corresponding to the message is generated no matter how many receivers the sender has chosen. It can be applied to video conferencing systems, pay-per-view channels, remote education, and so forth. Due to privacy considerations, an authorized receiver may not expect that his identity is revealed. In 2010, anonymous multi-receiver identity-based (ID-based encryption was first discussed, and furthermore, many works on the topic have been presented so far. Unfortunately, we find that all of those schemes fail to prove the chosen ciphertext attacks (CCA security in either confidentiality or anonymity. In this manuscript, we propose the first anonymous multi-receiver ID-based authenticated encryption scheme with CCA security in both confidentiality and anonymity. In the proposed scheme, the identity of the sender of a ciphertext can be authenticated by the receivers after a successful decryption. In addition, the proposed scheme also is the first CCA-secure one against insider attacks. Moreover, only one pairing computation is required in decryption.

  1. A new Identity Based Encryption (IBE) scheme using extended Chebyshev polynomial over finite fields Zp

    International Nuclear Information System (INIS)

    Benasser Algehawi, Mohammed; Samsudin, Azman

    2010-01-01

    We present a method to extract key pairs needed for the Identity Based Encryption (IBE) scheme from extended Chebyshev polynomial over finite fields Z p . Our proposed scheme relies on the hard problem and the bilinear property of the extended Chebyshev polynomial over Z p . The proposed system is applicable, secure, and reliable.

  2. Single-channel color image encryption using phase retrieve algorithm in fractional Fourier domain

    Science.gov (United States)

    Sui, Liansheng; Xin, Meiting; Tian, Ailing; Jin, Haiyan

    2013-12-01

    A single-channel color image encryption is proposed based on a phase retrieve algorithm and a two-coupled logistic map. Firstly, a gray scale image is constituted with three channels of the color image, and then permuted by a sequence of chaotic pairs generated by the two-coupled logistic map. Secondly, the permutation image is decomposed into three new components, where each component is encoded into a phase-only function in the fractional Fourier domain with a phase retrieve algorithm that is proposed based on the iterative fractional Fourier transform. Finally, an interim image is formed by the combination of these phase-only functions and encrypted into the final gray scale ciphertext with stationary white noise distribution by using chaotic diffusion, which has camouflage property to some extent. In the process of encryption and decryption, chaotic permutation and diffusion makes the resultant image nonlinear and disorder both in spatial domain and frequency domain, and the proposed phase iterative algorithm has faster convergent speed. Additionally, the encryption scheme enlarges the key space of the cryptosystem. Simulation results and security analysis verify the feasibility and effectiveness of this method.

  3. Super-Encryption Implementation Using Monoalphabetic Algorithm and XOR Algorithm for Data Security

    Science.gov (United States)

    Rachmawati, Dian; Andri Budiman, Mohammad; Aulia, Indra

    2018-03-01

    The exchange of data that occurs offline and online is very vulnerable to the threat of data theft. In general, cryptography is a science and art to maintain data secrecy. An encryption is a cryptography algorithm in which data is transformed into cipher text, which is something that is unreadable and meaningless so it cannot be read or understood by other parties. In super-encryption, two or more encryption algorithms are combined to make it more secure. In this work, Monoalphabetic algorithm and XOR algorithm are combined to form a super- encryption. Monoalphabetic algorithm works by changing a particular letter into a new letter based on existing keywords while the XOR algorithm works by using logic operation XOR Since Monoalphabetic algorithm is a classical cryptographic algorithm and XOR algorithm is a modern cryptographic algorithm, this scheme is expected to be both easy-to-implement and more secure. The combination of the two algorithms is capable of securing the data and restoring it back to its original form (plaintext), so the data integrity is still ensured.

  4. Implementation of the On-the-fly Encryption for the Linux OS Based on Certified CPS

    Directory of Open Access Journals (Sweden)

    Alexander Mikhailovich Korotin

    2013-02-01

    Full Text Available The article is devoted to tools for on-the-fly encryption and a method to implement such tool for the Linux OS based on a certified CPS.The idea is to modify the existing tool named eCryptfs. Russian cryptographic algorithms will be used in the user and kernel modes.

  5. Parallel encryption for multi-channel images based on an optical joint transform correlator

    Science.gov (United States)

    Liu, Jie; Bai, Tingzhu; Shen, Xueju; Dou, Shuaifeng; Lin, Chao; Cai, Jianjun

    2017-08-01

    We propose an optical encryption method allowing the parallel encryption for multi-channel images based on a joint transform correlator (JTC). Distinguished from the conventional multi-image encryption methods, our proposed cryptosystem can encrypt multi-channel images simultaneously into a single ciphertext, which also can be used to recover arbitrary original images with corresponding keys. This method can achieve the compressed storage of ciphertext. In order to avoid the cross talk between multi-channel images, we restrict the respective joint power spectrum (JPS) into a specific area with optimized phase masks and split the multiple JPS by controlling the position of single JPS using the linear phase shifts. All of these operations are realized by optimizing and designing the phase masks which can be flexibly reconfigured on the spatial light modulator (SLM), leading to a feasible optical implementation with no increase of optical hardware and complexity. Computer simulations provide the validation for it. Experimental implementation is performed in a JTC-based cryptosystem to further verify the feasibility of our proposed method.

  6. High performance optical encryption based on computational ghost imaging with QR code and compressive sensing technique

    Science.gov (United States)

    Zhao, Shengmei; Wang, Le; Liang, Wenqiang; Cheng, Weiwen; Gong, Longyan

    2015-10-01

    In this paper, we propose a high performance optical encryption (OE) scheme based on computational ghost imaging (GI) with QR code and compressive sensing (CS) technique, named QR-CGI-OE scheme. N random phase screens, generated by Alice, is a secret key and be shared with its authorized user, Bob. The information is first encoded by Alice with QR code, and the QR-coded image is then encrypted with the aid of computational ghost imaging optical system. Here, measurement results from the GI optical system's bucket detector are the encrypted information and be transmitted to Bob. With the key, Bob decrypts the encrypted information to obtain the QR-coded image with GI and CS techniques, and further recovers the information by QR decoding. The experimental and numerical simulated results show that the authorized users can recover completely the original image, whereas the eavesdroppers can not acquire any information about the image even the eavesdropping ratio (ER) is up to 60% at the given measurement times. For the proposed scheme, the number of bits sent from Alice to Bob are reduced considerably and the robustness is enhanced significantly. Meantime, the measurement times in GI system is reduced and the quality of the reconstructed QR-coded image is improved.

  7. On Notions of Security for Deterministic Encryption, and Efficient Constructions Without Random Oracles

    NARCIS (Netherlands)

    S. Boldyreva; S. Fehr (Serge); A. O'Neill; D. Wagner

    2008-01-01

    textabstractThe study of deterministic public-key encryption was initiated by Bellare et al. (CRYPTO ’07), who provided the “strongest possible” notion of security for this primitive (called PRIV) and constructions in the random oracle (RO) model. We focus on constructing efficient deterministic

  8. A General Construction of IND-CCA2 Secure Public Key Encryption

    DEFF Research Database (Denmark)

    Kiltz, Eike; Malone-Lee, John

    2003-01-01

    We propose a general construction for public key encryption schemes that are IND-CCA2 secure in the random oracle model. We show that the scheme proposed in [1, 2] fits our general framework and moreover that our method of analysis leads to a more efficient security reduction....

  9. 76 FR 66666 - Basic Service Tier Encryption Compatibility Between Cable Systems and Consumer Electronics Equipment

    Science.gov (United States)

    2011-10-27

    ... entertainment, motor vehicle, public address and musical instrument amplifications.'' The SBA has developed a... tier based on the argument that the rule imposes more burdens than benefits as cable operators... asserted that while encryption of all service tiers has its benefits, it also imposes some burdens on...

  10. A Self-adaptive Bit-level Color Image Encryption Algorithm Based on Generalized Arnold Map

    Directory of Open Access Journals (Sweden)

    Ye Rui-Song

    2017-01-01

    Full Text Available A self-adaptive bit-level color image encryption algorithm based on generalized Arnold map is proposed. The red, green, blue components of the plain-image with height H and width W are decomposed into 8-bit planes and one three-dimensional bit matrix with size ze H×W×24 is obtained. The generalized Arnold map is used to generate pseudo-random sequences to scramble the resulted three-dimensional bit matrix by sort-based approach. The scrambled 3D bit matrix is then rearranged to be one scrambled color image. Chaotic sequences produced by another generalized Arnold map are used to diffuse the resulted red, green, blue components in a cross way to get more encryption effects. Self-adaptive strategy is adopted in both the scrambling stage and diffusion stage, meaning that the key streams are all related to the content of the plain-image and therefore the encryption algorithm show strong robustness against known/chosen plaintext attacks. Some other performances are carried out, including key space, key sensitivity, histogram, correlation coefficients between adjacent pixels, information entropy and difference attack analysis, etc. All the experimental results show that the proposed image encryption algorithm is secure and effective for practical application.

  11. A Very Compact AES-SPIHT Selective Encryption Computer Architecture Design with Improved S-Box

    Directory of Open Access Journals (Sweden)

    Jia Hao Kong

    2013-01-01

    Full Text Available The “S-box” algorithm is a key component in the Advanced Encryption Standard (AES due to its nonlinear property. Various implementation approaches have been researched and discussed meeting stringent application goals (such as low power, high throughput, low area, but the ultimate goal for many researchers is to find a compact and small hardware footprint for the S-box circuit. In this paper, we present our version of minimized S-box with two separate proposals and improvements in the overall gate count. The compact S-box is adopted with a compact and optimum processor architecture specifically tailored for the AES, namely, the compact instruction set architecture (CISA. To further justify and strengthen the purpose of the compact crypto-processor’s application, we have also presented a selective encryption architecture (SEA which incorporates the CISA as a part of the encryption core, accompanied by the set partitioning in hierarchical trees (SPIHT algorithm as a complete selective encryption system.

  12. A network identity authentication protocol of bank account system based on fingerprint identification and mixed encryption

    Science.gov (United States)

    Zhu, Lijuan; Liu, Jingao

    2013-07-01

    This paper describes a network identity authentication protocol of bank account system based on fingerprint identification and mixed encryption. This protocol can provide every bank user a safe and effective way to manage his own bank account, and also can effectively prevent the hacker attacks and bank clerk crime, so that it is absolute to guarantee the legitimate rights and interests of bank users.

  13. Phase-only optical encryption based on the zeroth-order phase-contrast technique

    Science.gov (United States)

    Pizolato, José Carlos; Neto, Luiz Gonçalves

    2009-09-01

    A phase-only encryption/decryption scheme with the readout based on the zeroth-order phase-contrast technique (ZOPCT), without the use of a phase-changing plate on the Fourier plane of an optical system based on the 4f optical correlator, is proposed. The encryption of a gray-level image is achieved by multiplying the phase distribution obtained directly from the gray-level image by a random phase distribution. The robustness of the encoding is assured by the nonlinearity intrinsic to the proposed phase-contrast method and the random phase distribution used in the encryption process. The experimental system has been implemented with liquid-crystal spatial modulators to generate phase-encrypted masks and a decrypting key. The advantage of this method is the easy scheme to recover the gray-level information from the decrypted phase-only mask applying the ZOPCT. An analysis of this decryption method was performed against brute force attacks.

  14. Symmetric encryption algorithms using chaotic and non-chaotic generators: A review.

    Science.gov (United States)

    Radwan, Ahmed G; AbdElHaleem, Sherif H; Abd-El-Hafiz, Salwa K

    2016-03-01

    This paper summarizes the symmetric image encryption results of 27 different algorithms, which include substitution-only, permutation-only or both phases. The cores of these algorithms are based on several discrete chaotic maps (Arnold's cat map and a combination of three generalized maps), one continuous chaotic system (Lorenz) and two non-chaotic generators (fractals and chess-based algorithms). Each algorithm has been analyzed by the correlation coefficients between pixels (horizontal, vertical and diagonal), differential attack measures, Mean Square Error (MSE), entropy, sensitivity analyses and the 15 standard tests of the National Institute of Standards and Technology (NIST) SP-800-22 statistical suite. The analyzed algorithms include a set of new image encryption algorithms based on non-chaotic generators, either using substitution only (using fractals) and permutation only (chess-based) or both. Moreover, two different permutation scenarios are presented where the permutation-phase has or does not have a relationship with the input image through an ON/OFF switch. Different encryption-key lengths and complexities are provided from short to long key to persist brute-force attacks. In addition, sensitivities of those different techniques to a one bit change in the input parameters of the substitution key as well as the permutation key are assessed. Finally, a comparative discussion of this work versus many recent research with respect to the used generators, type of encryption, and analyses is presented to highlight the strengths and added contribution of this paper.

  15. A novel image encryption scheme based on the ergodicity of baker map

    Science.gov (United States)

    Ye, Ruisong; Chen, Yonghong

    2012-01-01

    Thanks to the exceptionally good properties in chaotic systems, such as sensitivity to initial conditions and control parameters, pseudo-randomness and ergodicity, chaos-based image encryption algorithms have been widely studied and developed in recent years. A novel digital image encryption scheme based on the chaotic ergodicity of Baker map is proposed in this paper. Different from traditional encryption schemes based on Baker map, we permute the pixel positions by their corresponding order numbers deriving from the approximating points in one chaotic orbit. To enhance the resistance to statistical and differential attacks, a diffusion process is suggested as well in the proposed scheme. The proposed scheme enlarges the key space significantly to resist brute-force attack. Additionally, the distribution of gray values in the cipher-image has a random-like behavior to resist statistical analysis. The proposed scheme is robust against cropping, tampering and noising attacks as well. It therefore suggests a high secure and efficient way for real-time image encryption and transmission in practice.

  16. Chaotic image encryption based on running-key related to plaintext.

    Science.gov (United States)

    Guanghui, Cao; Kai, Hu; Yizhi, Zhang; Jun, Zhou; Xing, Zhang

    2014-01-01

    In the field of chaotic image encryption, the algorithm based on correlating key with plaintext has become a new developing direction. However, for this kind of algorithm, some shortcomings in resistance to reconstruction attack, efficient utilization of chaotic resource, and reducing dynamical degradation of digital chaos are found. In order to solve these problems and further enhance the security of encryption algorithm, based on disturbance and feedback mechanism, we present a new image encryption scheme. In the running-key generation stage, by successively disturbing chaotic stream with cipher-text, the relation of running-key to plaintext is established, reconstruction attack is avoided, effective use of chaotic resource is guaranteed, and dynamical degradation of digital chaos is minimized. In the image encryption stage, by introducing random-feedback mechanism, the difficulty of breaking this scheme is increased. Comparing with the-state-of-the-art algorithms, our scheme exhibits good properties such as large key space, long key period, and extreme sensitivity to the initial key and plaintext. Therefore, it can resist brute-force, reconstruction attack, and differential attack.

  17. Comment on ‘A technique for image encryption using digital signature’

    Science.gov (United States)

    Hernández Encinas, L.; Peinado Domínguez, A.

    2006-12-01

    The security of a recently proposed technique for encryption images by Sinha and Singh [A. Sinha, K. Singh, Opt. Commun. 218 (2003) 229], based on the use of digital signatures and error correcting codes, is analyzed. The proposed cryptosystem is shown to have some weakness. In fact, the secret key and the original image can be recovered efficiently by a brute force attack.

  18. Chaotic Image Encryption Based on Running-Key Related to Plaintext

    Directory of Open Access Journals (Sweden)

    Cao Guanghui

    2014-01-01

    Full Text Available In the field of chaotic image encryption, the algorithm based on correlating key with plaintext has become a new developing direction. However, for this kind of algorithm, some shortcomings in resistance to reconstruction attack, efficient utilization of chaotic resource, and reducing dynamical degradation of digital chaos are found. In order to solve these problems and further enhance the security of encryption algorithm, based on disturbance and feedback mechanism, we present a new image encryption scheme. In the running-key generation stage, by successively disturbing chaotic stream with cipher-text, the relation of running-key to plaintext is established, reconstruction attack is avoided, effective use of chaotic resource is guaranteed, and dynamical degradation of digital chaos is minimized. In the image encryption stage, by introducing random-feedback mechanism, the difficulty of breaking this scheme is increased. Comparing with the-state-of-the-art algorithms, our scheme exhibits good properties such as large key space, long key period, and extreme sensitivity to the initial key and plaintext. Therefore, it can resist brute-force, reconstruction attack, and differential attack.

  19. Ubi-RKE: A Rhythm Key Based Encryption Scheme for Ubiquitous Devices

    Directory of Open Access Journals (Sweden)

    Jae Dong Lee

    2014-01-01

    Full Text Available As intelligent ubiquitous devices become more popular, security threats targeting them are increasing; security is seen as one of the major challenges of the ubiquitous computing. Now a days, applying ubiquitous computing in number of fields for human safety and convenience was immensely increased in recent years. The popularity of the technology is rising day by day, and hence the security is becoming the main focused point with the advent and rising popularity of the applications. In particular, the number of wireless networks based on ubiquitous devices has increased rapidly; these devices support transmission for many types of data traffic. The convenient portability of ubiquitous devices makes them vulnerable to security threats, such as loss, theft, data modification, and wiretapping. Developers and users should seriously consider employing data encryption to protect data from such vulnerabilities. In this paper, we propose a Rhythm Key based Encryption scheme for ubiquitous devices (Ubi-RKE. The concept of Rhythm Key based Encryption has been applied to numerous real world applications in different domains. It provides key memorability and secure encryption through user touching rhythm on ubiquitous devices. Our proposed scheme is more efficient for users than existing schemes, by providing a strong cipher.

  20. Efficiently Multi-User Searchable Encryption Scheme with Attribute Revocation and Grant for Cloud Storage.

    Science.gov (United States)

    Wang, Shangping; Zhang, Xiaoxue; Zhang, Yaling

    2016-01-01

    Cipher-policy attribute-based encryption (CP-ABE) focus on the problem of access control, and keyword-based searchable encryption scheme focus on the problem of finding the files that the user interested in the cloud storage quickly. To design a searchable and attribute-based encryption scheme is a new challenge. In this paper, we propose an efficiently multi-user searchable attribute-based encryption scheme with attribute revocation and grant for cloud storage. In the new scheme the attribute revocation and grant processes of users are delegated to proxy server. Our scheme supports multi attribute are revoked and granted simultaneously. Moreover, the keyword searchable function is achieved in our proposed scheme. The security of our proposed scheme is reduced to the bilinear Diffie-Hellman (BDH) assumption. Furthermore, the scheme is proven to be secure under the security model of indistinguishability against selective ciphertext-policy and chosen plaintext attack (IND-sCP-CPA). And our scheme is also of semantic security under indistinguishability against chosen keyword attack (IND-CKA) in the random oracle model.

  1. Efficiently Multi-User Searchable Encryption Scheme with Attribute Revocation and Grant for Cloud Storage.

    Directory of Open Access Journals (Sweden)

    Shangping Wang

    Full Text Available Cipher-policy attribute-based encryption (CP-ABE focus on the problem of access control, and keyword-based searchable encryption scheme focus on the problem of finding the files that the user interested in the cloud storage quickly. To design a searchable and attribute-based encryption scheme is a new challenge. In this paper, we propose an efficiently multi-user searchable attribute-based encryption scheme with attribute revocation and grant for cloud storage. In the new scheme the attribute revocation and grant processes of users are delegated to proxy server. Our scheme supports multi attribute are revoked and granted simultaneously. Moreover, the keyword searchable function is achieved in our proposed scheme. The security of our proposed scheme is reduced to the bilinear Diffie-Hellman (BDH assumption. Furthermore, the scheme is proven to be secure under the security model of indistinguishability against selective ciphertext-policy and chosen plaintext attack (IND-sCP-CPA. And our scheme is also of semantic security under indistinguishability against chosen keyword attack (IND-CKA in the random oracle model.

  2. Image Encryption Scheme Based on Balanced Two-Dimensional Cellular Automata

    Directory of Open Access Journals (Sweden)

    Xiaoyan Zhang

    2013-01-01

    Full Text Available Cellular automata (CA are simple models of computation which exhibit fascinatingly complex behavior. Due to the universality of CA model, it has been widely applied in traditional cryptography and image processing. The aim of this paper is to present a new image encryption scheme based on balanced two-dimensional cellular automata. In this scheme, a random image with the same size of the plain image to be encrypted is first generated by a pseudo-random number generator with a seed. Then, the random image is evoluted alternately with two balanced two-dimensional CA rules. At last, the cipher image is obtained by operating bitwise XOR on the final evolution image and the plain image. This proposed scheme possesses some advantages such as very large key space, high randomness, complex cryptographic structure, and pretty fast encryption/decryption speed. Simulation results obtained from some classical images at the USC-SIPI database demonstrate the strong performance of the proposed image encryption scheme.

  3. Finite Precision Logistic Map between Computational Efficiency and Accuracy with Encryption Applications

    Directory of Open Access Journals (Sweden)

    Wafaa S. Sayed

    2017-01-01

    Full Text Available Chaotic systems appear in many applications such as pseudo-random number generation, text encryption, and secure image transfer. Numerical solutions of these systems using digital software or hardware inevitably deviate from the expected analytical solutions. Chaotic orbits produced using finite precision systems do not exhibit the infinite period expected under the assumptions of infinite simulation time and precision. In this paper, digital implementation of the generalized logistic map with signed parameter is considered. We present a fixed-point hardware realization of a Pseudo-Random Number Generator using the logistic map that experiences a trade-off between computational efficiency and accuracy. Several introduced factors such as the used precision, the order of execution of the operations, parameter, and initial point values affect the properties of the finite precision map. For positive and negative parameter cases, the studied properties include bifurcation points, output range, maximum Lyapunov exponent, and period length. The performance of the finite precision logistic map is compared in the two cases. A basic stream cipher system is realized to evaluate the system performance for encryption applications for different bus sizes regarding the encryption key size, hardware requirements, maximum clock frequency, NIST and correlation, histogram, entropy, and Mean Absolute Error analyses of encrypted images.

  4. ANALYSIS OF TIME DISTANCES OF ENCRYPTION/DECRYPTION OF MEDICAL INFORMATION SYSTEMS DATABASES FILES

    Directory of Open Access Journals (Sweden)

    Ye. B. Lopin

    2014-02-01

    Full Text Available In the article on the specific example the results of studies medical information systems databases files encryption/decryptiontime have been presented. The present studies are performed using the developed three fundamentally different algorithms, that include Blowfish encryption algorithm as a part. The studies were performed using a specially developed (in the programming environment Delphi 7 computer program "Generators" (author's title and two computers having obsolete configuration and assembled with the Intel Core 2 Duo E8400 processor and the DualCore Intel Pentium E2180 processor. The studies have established that the encryption/decryption of files using the first developed algorithm during execution of which multiple access to the hard drive for reading/writing of 8-byte information blocks of is implemented, takes much longer time (about 10 times than the encryption/decryption using the second and third algorithms during execution of which access to the hard drive for a file reading/writing is performed once.

  5. DMAC-AN INTEGRATED ENCRYPTION SCHEME WITH RSA FOR AC TO OBSTRUCT INFERENCE ATTACKS

    Directory of Open Access Journals (Sweden)

    R. Jeeva

    2012-12-01

    Full Text Available The proposal of indistinguishable encryption in Randomized Arithmetic Coding(RAC doesn’t make the system efficient because it was not encrypting the messages it sends. It recomputes the cipher form of every messages it sends that increases not only the computational cost but also increases the response time.Floating point representation in cipher increases the difficulty in decryption side because of loss in precison.RAC doesn’t handle the inference attacks like Man-in-Middle attack,Third party attack etc. In our system, Dynamic Matrix Arithmetic Coding(DMAC using dynamic session matrix to encrypt the messages. The size of the matrix is deduced from the session key that contains ID of end users which proves the server authentication.Nonce values is represented as the public key of the opponents encrypted by the session key will be exchanged between the end users to provide mutual authentication. If the adversary try to compromise either server or end users,the other system won’t respond and the intrusion will be easily detected. we have increased the hacking complexity of AC by integrating with RSA upto 99%.

  6. Public key encryption supporting plaintext equality test and user-specified authorization

    NARCIS (Netherlands)

    Tang, Qiang

    2012-01-01

    In this paper, we investigate a category of public key encryption schemes that supports plaintext equality test and userspecified authorization. With this new primitive, two users, who possess their own public/private key pairs, can issue token(s) to a proxy to authorize it to perform plaintext

  7. Chaos-based encryption keys and neural key-store for cloud-hosted data confidentiality

    CSIR Research Space (South Africa)

    Mosola, NN

    2017-09-01

    Full Text Available towards gaining unauthorised access to cloud-bound or cloud-hosted data. This paper proposes a client-end encryption and key management system to curb attacks that targets compromising the confidentiality of cloud-hosted data. The proposed system uses...

  8. A Block Compressive Sensing Based Scalable Encryption Framework for Protecting Significant Image Regions

    Science.gov (United States)

    Zhang, Yushu; Zhou, Jiantao; Chen, Fei; Zhang, Leo Yu; Xiao, Di; Chen, Bin; Liao, Xiaofeng

    The existing Block Compressive Sensing (BCS) based image ciphers adopted the same sampling rate for all the blocks, which may lead to the desirable result that after subsampling, significant blocks lose some more-useful information while insignificant blocks still retain some less-useful information. Motivated by this observation, we propose a scalable encryption framework (SEF) based on BCS together with a Sobel Edge Detector and Cascade Chaotic Maps. Our work is firstly dedicated to the design of two new fusion techniques, chaos-based structurally random matrices and chaos-based random convolution and subsampling. The basic idea is to divide an image into some blocks with an equal size and then diagnose their respective significance with the help of the Sobel Edge Detector. For significant block encryption, chaos-based structurally random matrix is applied to significant blocks whereas chaos-based random convolution and subsampling are responsible for the remaining insignificant ones. In comparison with the BCS based image ciphers, the SEF takes lightweight subsampling and severe sensitivity encryption for the significant blocks and severe subsampling and lightweight robustness encryption for the insignificant ones in parallel, thus better protecting significant image regions.

  9. MiMC: Efficient encryption and cryptographic hashing with minimal multiplicative complexity

    DEFF Research Database (Denmark)

    Albrecht, Martin; Grassi, Lorenzo; Rechberger, Christian

    2016-01-01

    We explore cryptographic primitives with low multiplicative complexity. This is motivated by recent progress in practical applications of secure multi-party computation (MPC), fully homomorphic encryption (FHE), and zero-knowledge proofs (ZK) where primitives from symmetric cryptography are needed...

  10. An implementation of super-encryption using RC4A and MDTM cipher algorithms for securing PDF Files on android

    Science.gov (United States)

    Budiman, M. A.; Rachmawati, D.; Parlindungan, M. R.

    2018-03-01

    MDTM is a classical symmetric cryptographic algorithm. As with other classical algorithms, the MDTM Cipher algorithm is easy to implement but it is less secure compared to modern symmetric algorithms. In order to make it more secure, a stream cipher RC4A is added and thus the cryptosystem becomes super encryption. In this process, plaintexts derived from PDFs are firstly encrypted with the MDTM Cipher algorithm and are encrypted once more with the RC4A algorithm. The test results show that the value of complexity is Θ(n2) and the running time is linearly directly proportional to the length of plaintext characters and the keys entered.

  11. Devil’s Vortex Phase Structure as Frequency Plane Mask for Image Encryption Using the Fractional Mellin Transform

    Directory of Open Access Journals (Sweden)

    Sunanda Vashisth

    2014-01-01

    Full Text Available A frequency plane phase mask based on Devil’s vortex structure has been used for image encryption using the fractional Mellin transform. The phase key for decryption is obtained by an iterative phase retrieval algorithm. The proposed scheme has been validated for grayscale secret target images, by numerical simulation. The efficacy of the scheme has been evaluated by computing mean-squared-error between the secret target image and the decrypted image. Sensitivity analysis of the decryption process to variations in various encryption parameters has been carried out. The proposed encryption scheme has been seen to exhibit reasonable robustness against occlusion attack.

  12. Cognitive approaches for patterns analysis and security applications

    Science.gov (United States)

    Ogiela, Marek R.; Ogiela, Lidia

    2017-08-01

    In this paper will be presented new opportunities for developing innovative solutions for semantic pattern classification and visual cryptography, which will base on cognitive and bio-inspired approaches. Such techniques can be used for evaluation of the meaning of analyzed patterns or encrypted information, and allow to involve such meaning into the classification task or encryption process. It also allows using some crypto-biometric solutions to extend personalized cryptography methodologies based on visual pattern analysis. In particular application of cognitive information systems for semantic analysis of different patterns will be presented, and also a novel application of such systems for visual secret sharing will be described. Visual shares for divided information can be created based on threshold procedure, which may be dependent on personal abilities to recognize some image details visible on divided images.

  13. Watermarking spot colors in packaging

    Science.gov (United States)

    Reed, Alastair; Filler, TomáÅ.¡; Falkenstern, Kristyn; Bai, Yang

    2015-03-01

    In January 2014, Digimarc announced Digimarc® Barcode for the packaging industry to improve the check-out efficiency and customer experience for retailers. Digimarc Barcode is a machine readable code that carries the same information as a traditional Universal Product Code (UPC) and is introduced by adding a robust digital watermark to the package design. It is imperceptible to the human eye but can be read by a modern barcode scanner at the Point of Sale (POS) station. Compared to a traditional linear barcode, Digimarc Barcode covers the whole package with minimal impact on the graphic design. This significantly improves the Items per Minute (IPM) metric, which retailers use to track the checkout efficiency since it closely relates to their profitability. Increasing IPM by a few percent could lead to potential savings of millions of dollars for retailers, giving them a strong incentive to add the Digimarc Barcode to their packages. Testing performed by Digimarc showed increases in IPM of at least 33% using the Digimarc Barcode, compared to using a traditional barcode. A method of watermarking print ready image data used in the commercial packaging industry is described. A significant proportion of packages are printed using spot colors, therefore spot colors needs to be supported by an embedder for Digimarc Barcode. Digimarc Barcode supports the PANTONE spot color system, which is commonly used in the packaging industry. The Digimarc Barcode embedder allows a user to insert the UPC code in an image while minimizing perceptibility to the Human Visual System (HVS). The Digimarc Barcode is inserted in the printing ink domain, using an Adobe Photoshop plug-in as the last step before printing. Since Photoshop is an industry standard widely used by pre-press shops in the packaging industry, a Digimarc Barcode can be easily inserted and proofed.

  14. Spot distribution and fast surface evolution on Vega

    Science.gov (United States)

    Petit, P.; Hébrard, E. M.; Böhm, T.; Folsom, C. P.; Lignières, F.

    2017-11-01

    Spectral signatures of surface spots were recently discovered from high cadence observations of the A star Vega. We aim at constraining the surface distribution of these photospheric inhomogeneities and investigating a possible short-term evolution of the spot pattern. Using data collected over five consecutive nights, we employ the Doppler imaging method to reconstruct three different maps of the stellar surface, from three consecutive subsets of the whole time series. The surface maps display a complex distribution of dark and bright spots, covering most of the visible fraction of the stellar surface. A number of surface features are consistently recovered in all three maps, but other features seem to evolve over the time span of observations, suggesting that fast changes can affect the surface of Vega within a few days at most. The short-term evolution is observed as emergence or disappearance of individual spots, and may also show up as zonal flows, with low- and high-latitude belts rotating faster than intermediate latitudes. It is tempting to relate the surface brightness activity to the complex magnetic field topology previously reconstructed for Vega, although strictly simultaneous brightness and magnetic maps will be necessary to assess this potential link.

  15. Experiments of Nanometer Spot Size Monitor at FETB Using Laser Interferometry

    CERN Document Server

    Walz, D

    2003-01-01

    The nanometer spot size monitor based on the laser interferometry has been developed and installed in the final focus test beam (FFTB) line at SLAC. The beam experiments started in September 1993, the first fringe pattern from the monitor was observed in the beginning of April 1994, then the small vertical spot around 70 nm was observed in May 1994. The spot size monitor has been routinely used for tuning the beam optics in FFTB. Basic principle of this monitor has been well proved, and its high performance as a precise beam monitor in nanometer range has been demonstrated.

  16. Oil futures and spot markets

    International Nuclear Information System (INIS)

    Samii, M.V.

    1992-01-01

    In the last decade, the oil futures market has risen to prominence and has become a major factor in influencing oil market psychology and the crude oil market. On a normal day, over 92 thousand contracts, the equivalent of 92 million barrels per day, change hands on the New York Mercantile Exchange, NYMEX. This market has provided a vehicle for hedging against risk. At the same time, it has also created opportunities for speculation. Those who previously were unable to participate in oil market transactions can now become involved through the futures market. The large number of participants in the future market and the availability of information has made this market more efficient and transparent, relative to the crude oil market. While there has been considerable in-depth analysis of other future markets, relatively little theoretical attention has focused on that of oil. This paper looks at the following issues. First, what is the relationship between futures and spot oil prices? And secondly, are futures prices a good predictor of spot crude prices in the future? (author)

  17. Integrating sustainable hunting in biodiversity protection in Central Africa: hot spots, weak spots, and strong spots.

    Directory of Open Access Journals (Sweden)

    John E Fa

    Full Text Available Wild animals are a primary source of protein (bushmeat for people living in or near tropical forests. Ideally, the effect of bushmeat harvests should be monitored closely by making regular estimates of offtake rate and size of stock available for exploitation. However, in practice, this is possible in very few situations because it requires both of these aspects to be readily measurable, and even in the best case, entails very considerable time and effort. As alternative, in this study, we use high-resolution, environmental favorability models for terrestrial mammals (N = 165 in Central Africa to map areas of high species richness (hot spots and hunting susceptibility. Favorability models distinguish localities with environmental conditions that favor the species' existence from those with detrimental characteristics for its presence. We develop an index for assessing Potential Hunting Sustainability (PHS of each species based on their ecological characteristics (population density, habitat breadth, rarity and vulnerability, weighted according to restrictive and permissive assumptions of how species' characteristics are combined. Species are classified into five main hunting sustainability classes using fuzzy logic. Using the accumulated favorability values of all species, and their PHS values, we finally identify weak spots, defined as high diversity regions of especial hunting vulnerability for wildlife, as well as strong spots, defined as high diversity areas of high hunting sustainability potential. Our study uses relatively simple models that employ easily obtainable data of a species' ecological characteristics to assess the impacts of hunting in tropical regions. It provides information for management by charting the geography of where species are more or less likely to be at risk of extinction from hunting.

  18. A chaotic modified-DFT encryption scheme for physical layer security and PAPR reduction in OFDM-PON

    Science.gov (United States)

    Fu, Xiaosong; Bi, Meihua; Zhou, Xuefang; Yang, Guowei; Li, Qiliang; Zhou, Zhao; Yang, Xuelin

    2018-05-01

    This letter proposes a modified discrete Fourier transform (DFT) encryption scheme with multi-dimensional chaos for the physical layer security and peak-to-average power ratio (PAPR) reduction in orthogonal frequency division multiplexing passive optical network (OFDM-PON) system. This multiple-fold encryption algorithm is mainly composed by using the column vectors permutation and the random phase encryption in the standard DFT matrix, which can create ∼10551 key space. The transmission of ∼10 Gb/s encrypted OFDM signal is verified over 20-km standard single mode fiber (SMF). Moreover, experimental results show that, the proposed scheme can achieve ∼2.6-dB PAPR reduction and ∼1-dB improvement of receiver sensitivity if compared with the common OFDM-PON.

  19. Optical image encryption using chaos-based compressed sensing and phase-shifting interference in fractional wavelet domain

    Science.gov (United States)

    Liu, Qi; Wang, Ying; Wang, Jun; Wang, Qiong-Hua

    2018-02-01

    In this paper, a novel optical image encryption system combining compressed sensing with phase-shifting interference in fractional wavelet domain is proposed. To improve the encryption efficiency, the volume data of original image are decreased by compressed sensing. Then the compacted image is encoded through double random phase encoding in asymmetric fractional wavelet domain. In the encryption system, three pseudo-random sequences, generated by three-dimensional chaos map, are used as the measurement matrix of compressed sensing and two random-phase masks in the asymmetric fractional wavelet transform. It not only simplifies the keys to storage and transmission, but also enhances our cryptosystem nonlinearity to resist some common attacks. Further, holograms make our cryptosystem be immune to noises and occlusion attacks, which are obtained by two-step-only quadrature phase-shifting interference. And the compression and encryption can be achieved in the final result simultaneously. Numerical experiments have verified the security and validity of the proposed algorithm.

  20. Encryption and watermark-treated medical image against hacking disease-An immune convention in spatial and frequency domains.

    Science.gov (United States)

    Lakshmi, C; Thenmozhi, K; Rayappan, John Bosco Balaguru; Amirtharajan, Rengarajan

    2018-06-01

    Digital Imaging and Communications in Medicine (DICOM) is one among the significant formats used worldwide for the representation of medical images. Undoubtedly, medical-image security plays a crucial role in telemedicine applications. Merging encryption and watermarking in medical-image protection paves the way for enhancing the authentication and safer transmission over open channels. In this context, the present work on DICOM image encryption has employed a fuzzy chaotic map for encryption and the Discrete Wavelet Transform (DWT) for watermarking. The proposed approach overcomes the limitation of the Arnold transform-one of the most utilised confusion mechanisms in image ciphering. Various metrics have substantiated the effectiveness of the proposed medical-image encryption algorithm. Copyright © 2018 Elsevier B.V. All rights reserved.

  1. Power Adaptive Data Encryption for Energy-Efficient and Secure Communication in Solar-Powered Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Jong Min Kim

    2016-01-01

    Full Text Available Basic security of data transmission in battery-powered wireless sensor networks (WSNs is typically achieved by symmetric-key encryption, which uses little energy; but solar-powered WSNs sometimes have sufficient energy to achieve a higher level of security through public-key encryption. However, if energy input and usage are not balanced, nodes may black out. By switching between symmetric-key and public-key encryption, based on an energy threshold, the level of security can be traded off against the urgency of energy-saving. This policy can also reduce the amount of energy used by some nodes in a WSN, since data encrypted using a public-key is simply relayed by intermediate nodes, whereas data encrypted using a symmetric-key must be decrypted and reencrypted in every node on its path. Through a simulation, we compared the use of either symmetric-key or public-key encryption alone with our scheme, which was shown to be more secure, to use energy more effectively, and to reduce the occurrence of node blackouts.

  2. How to reuse a one-time pad and other notes on authentication, encryption, and protection of quantum information

    International Nuclear Information System (INIS)

    Oppenheim, Jonathan; Horodecki, Michal

    2005-01-01

    Quantum information is a valuable resource which can be encrypted in order to protect it. We consider the size of the one-time pad that is needed to protect quantum information in a number of cases. The situation is dramatically different from the classical case: we prove that one can recycle the one-time pad without compromising security. The protocol for recycling relies on detecting whether eavesdropping has occurred, and further relies on the fact that information contained in the encrypted quantum state cannot be fully accessed. We prove the security of recycling rates when authentication of quantum states is accepted, and when it is rejected. We note that recycling schemes respect a general law of cryptography which we introduce relating the size of private keys, sent qubits, and encrypted messages. We discuss applications for encryption of quantum information in light of the resources needed for teleportation. Potential uses include the protection of resources such as entanglement and the memory of quantum computers. We also introduce another application: encrypted secret sharing and find that one can even reuse the private key that is used to encrypt a classical message. In a number of cases, one finds that the amount of private key needed for authentication or protection is smaller than in the general case

  3. A novel block encryption scheme based on chaos and an S-box for wireless sensor networks

    International Nuclear Information System (INIS)

    Tong Xiao-Jun; Zuo Ke; Wang Zhu

    2012-01-01

    The wireless sensor network (WSN) has been widely used in various fields, but it still remains in the preliminary discovery and research phase with a lack of various related mature technologies. Traditional encryption schemes are not suitable for wireless sensor networks due to intrinsic features of the nodes such as low energy, limited computation capability, and lack of storage resources. In this paper, we present a novel block encryption scheme based on the integer discretization of a chaotic map, the Feistel network structure, and an S-box. The novel scheme is fast, secure, has low resource consumption and is suitable for wireless sensor network node encryption schemes. The experimental tests are carried out with detailed analysis, showing that the novel block algorithm has a large key space, very good diffusion and disruptive performances, a strict avalanche effect, excellent statistical balance, and fast encryption speed. These features enable the encryption scheme to pass the SP800-22 test. Meanwhile, the analysis and the testing of speed, time, and storage space on the simulator platform show that this new encryption scheme is well able to hide data information in wireless sensor networks. (general)

  4. A Stream Encryption Scheme with Both Key and Plaintext Avalanche Effects for Designing Chaos-Based Pseudorandom Number Generator with Application to Image Encryption

    Science.gov (United States)

    Han, Dandan; Min, Lequan; Chen, Guanrong

    Based on a stream encryption scheme with avalanche effect (SESAE), a stream encryption scheme with both key avalanche effect and plaintext avalanche effect (SESKPAE) is introduced. Using this scheme and an ideal 2d-word (d-segment) pseudorandom number generator (PRNG), a plaintext can be encrypted such that each bit of the ciphertext block has a change with the probable probability of (2d - 1)/2d when any word of the key is changed or any bit of the plaintext is changed. To that end, a novel four-dimensional discrete chaotic system (4DDCS) is proposed. Combining the 4DDCS with a generalized synchronization (GS) theorem, a novel eight-dimensional discrete GS chaotic system (8DDGSCS) is constructed. Using the 8DDGSCS, a 216-word chaotic pseudorandom number generator (CPRNG) is designed. The keyspace of the 216-word CPRNG is larger than 21195. Then, the FIPS 140-2 test suit/generalized FIPS 140-2 test suit is used to test the randomness of the 1000-key streams consisting of 20000 bits generated by the 216-word CPRNG, the RC4 algorithm PRNG and the ZUC algorithm PRNG, respectively. The test results show that for the three PRNGs, there are 100%/98.9%, 99.9%/98.8%, 100%/97.9% key streams passing the tests, respectively. Furthermore, the SP800-22 test suite is used to test the randomness of four 100-key streams consisting of 1000000 bits generated by four PRNGs, respectively. The numerical results show that the randomness performances of the 216-word CPRNG is promising, showing that there are no significant correlations between the key streams and the perturbed key streams generated via the 216-word CPRNG. Finally, using the 216-word CPRNG and the SESKPAE to encrypt two gray-scale images, test results demonstrate that the 216-word CPRNG is able to generate both key avalanche effect and plaintext avalanche effect, which are similar to those generated via an ideal CPRNG, and performs better than other comparable schemes.

  5. Butterfly Wings Are Three-Dimensional: Pupal Cuticle Focal Spots and Their Associated Structures in Junonia Butterflies.

    Science.gov (United States)

    Taira, Wataru; Otaki, Joji M

    2016-01-01

    Butterfly wing color patterns often contain eyespots, which are developmentally determined at the late larval and early pupal stages by organizing activities of focal cells that can later form eyespot foci. In the pupal stage, the focal position of a future eyespot is often marked by a focal spot, one of the pupal cuticle spots, on the pupal surface. Here, we examined the possible relationships of the pupal focal spots with the underneath pupal wing tissues and with the adult wing eyespots using Junonia butterflies. Large pupal focal spots were found in two species with large adult eyespots, J. orithya and J. almana, whereas only small pupal focal spots were found in a species with small adult eyespots, J. hedonia. The size of five pupal focal spots on a single wing was correlated with the size of the corresponding adult eyespots in J. orithya. A pupal focal spot was a three-dimensional bulge of cuticle surface, and the underside of the major pupal focal spot exhibited a hollowed cuticle in a pupal case. Cross sections of a pupal wing revealed that the cuticle layer shows a curvature at a focal spot, and a positional correlation was observed between the cuticle layer thickness and its corresponding cell layer thickness. Adult major eyespots of J. orithya and J. almana exhibited surface elevations and depressions that approximately correspond to the coloration within an eyespot. Our results suggest that a pupal focal spot is produced by the organizing activity of focal cells underneath the focal spot. Probably because the focal cell layer immediately underneath a focal spot is thicker than that of its surrounding areas, eyespots of adult butterfly wings are three-dimensionally constructed. The color-height relationship in adult eyespots might have an implication in the developmental signaling for determining the eyespot color patterns.

  6. Cosmicflows-3: Cold Spot Repeller?

    Energy Technology Data Exchange (ETDEWEB)

    Courtois, Hélène M.; Graziani, Romain; Dupuy, Alexandra [University of Lyon, UCB Lyon 1, CNRS/IN2P3, IPN, Lyon (France); Tully, R. Brent [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Hoffman, Yehuda [Racah Institute of Physics, Hebrew University, Jerusalem, 91904 (Israel); Pomarède, Daniel [Institut de Recherche sur les Lois Fondamentales de l’Univers, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette (France)

    2017-09-20

    The three-dimensional gravitational velocity field within z ∼ 0.1 has been modeled with the Wiener filter methodology applied to the Cosmicflows-3 compilation of galaxy distances. The dominant features are a basin of attraction and two basins of repulsion. The major basin of attraction is an extension of the Shapley concentration of galaxies. One basin of repulsion, the Dipole Repeller, is located near the anti-apex of the cosmic microwave background dipole. The other basin of repulsion is in the proximate direction toward the “Cold Spot” irregularity in the cosmic microwave background. It has been speculated that a vast void might contribute to the amplitude of the Cold Spot from the integrated Sachs–Wolfe effect.

  7. Reducing Dose Uncertainty for Spot-Scanning Proton Beam Therapy of Moving Tumors by Optimizing the Spot Delivery Sequence

    International Nuclear Information System (INIS)

    Li, Heng; Zhu, X. Ronald; Zhang, Xiaodong

    2015-01-01

    Purpose: To develop and validate a novel delivery strategy for reducing the respiratory motion–induced dose uncertainty of spot-scanning proton therapy. Methods and Materials: The spot delivery sequence was optimized to reduce dose uncertainty. The effectiveness of the delivery sequence optimization was evaluated using measurements and patient simulation. One hundred ninety-one 2-dimensional measurements using different delivery sequences of a single-layer uniform pattern were obtained with a detector array on a 1-dimensional moving platform. Intensity modulated proton therapy plans were generated for 10 lung cancer patients, and dose uncertainties for different delivery sequences were evaluated by simulation. Results: Without delivery sequence optimization, the maximum absolute dose error can be up to 97.2% in a single measurement, whereas the optimized delivery sequence results in a maximum absolute dose error of ≤11.8%. In patient simulation, the optimized delivery sequence reduces the mean of fractional maximum absolute dose error compared with the regular delivery sequence by 3.3% to 10.6% (32.5-68.0% relative reduction) for different patients. Conclusions: Optimizing the delivery sequence can reduce dose uncertainty due to respiratory motion in spot-scanning proton therapy, assuming the 4-dimensional CT is a true representation of the patients' breathing patterns.

  8. An optical authentication system based on encryption technique and multimodal biometrics

    Science.gov (United States)

    Yuan, Sheng; Zhang, Tong; Zhou, Xin; Liu, Xuemei; Liu, Mingtang

    2013-12-01

    A major concern nowadays for a biometric credential management system is its potential vulnerability to protect its information sources. To prevent a genuine user's templates from both internal and external threats, a novel and simple method combined optical encryption with multimodal biometric authentication technique is proposed. In this method, the standard biometric templates are generated real-timely by the verification keys owned by legal user so that they are unnecessary to be stored in a database. Compared with the traditional recognition algorithms, storage space and matching time are greatly saved. In addition, the verification keys are difficult to be forged due to the utilization of optical encryption technique. Although the verification keys are lost or stolen, they are useless for others in absence of the legal owner's biometric. A series of numerical simulations are performed to demonstrate the feasibility and performance of this method.

  9. Cryptanalyzing an improved security modulated chaotic encryption scheme using ciphertext absolute value

    International Nuclear Information System (INIS)

    Alvarez, G.; Montoya, F.; Romera, M.; Pastor, G.

    2005-01-01

    This paper describes the security weakness of a recently proposed improved chaotic encryption method based on the modulation of a signal generated by a chaotic system with an appropriately chosen scalar signal. The aim of the improvement is to avoid the breaking of chaotic encryption schemes by means of the return map attack introduced by Perez and Cerdeira. A method of attack based on taking the absolute value of the ciphertext is presented, that allows for the cancellation of the modulation scalar signal and the determination of some system parameters that play the role of system key. The proposed improved method is shown to be compromised without any knowledge of the chaotic system parameter values and even without knowing the transmitter structure

  10. Impulse attack-free four random phase mask encryption based on a 4-f optical system.

    Science.gov (United States)

    Kumar, Pramod; Joseph, Joby; Singh, Kehar

    2009-04-20

    Optical encryption methods based on double random phase encryption (DRPE) have been shown to be vulnerable to different types of attacks. The Fourier plane random phase mask (RPM), which is the most important key, can be cracked with a single impulse function attack. Such an attack is viable because the Fourier transform of a delta function is a unity function. Formation of a unity function can be avoided if RPMs are placed in front of both lenses in a 4-f optical setup, thereby protecting the DRPE from an impulse attack. We have performed numerical simulations to verify the proposed scheme. Resistance of this scheme is checked against the brute force and the impulse function attacks. The experimental results validate the feasibility of the scheme.

  11. Optical image encryption using password key based on phase retrieval algorithm

    Science.gov (United States)

    Zhao, Tieyu; Ran, Qiwen; Yuan, Lin; Chi, Yingying; Ma, Jing

    2016-04-01

    A novel optical image encryption system is proposed using password key based on phase retrieval algorithm (PRA). In the encryption process, a shared image is taken as a symmetric key and the plaintext is encoded into the phase-only mask based on the iterative PRA. The linear relationship between the plaintext and ciphertext is broken using the password key, which can resist the known plaintext attack. The symmetric key and the retrieved phase are imported into the input plane and Fourier plane of 4f system during the decryption, respectively, so as to obtain the plaintext on the CCD. Finally, we analyse the key space of the password key, and the results show that the proposed scheme can resist a brute force attack due to the flexibility of the password key.

  12. Color Image Encryption Using Three-Dimensional Sine ICMIC Modulation Map and DNA Sequence Operations

    Science.gov (United States)

    Liu, Wenhao; Sun, Kehui; He, Yi; Yu, Mengyao

    Derived from Sine map and iterative chaotic map with infinite collapse (ICMIC), a three-dimensional hyperchaotic Sine ICMIC modulation map (3D-SIMM) is proposed based on a close-loop modulation coupling (CMC) method. Based on this map, a novel color image encryption algorithm is designed by employing a hybrid model of multidirectional circular permutation and deoxyribonucleic acid (DNA) masking. In this scheme, the pixel positions of image are scrambled by multidirectional circular permutation, and the pixel values are substituted by DNA sequence operations. The simulation results and security analysis show that the algorithm has good encryption effect and strong key sensitivity, and can resist brute-force, statistical, differential, known-plaintext and chosen-plaintext attacks.

  13. Optical image encryption with silhouette removal based on interference and phase blend processing

    Science.gov (United States)

    Wang, Qu

    2012-10-01

    To completely eliminate the silhouette problem that inherently exists in the earlier interference-based encryption scheme with two phase-only masks (POMs), we propose a simple new encryption method based on optical interference of one random POM and two analytically obtained POMs. Different from the previous methods which require time-consuming iterative computation or postprocessing of the POMs for silhouette removal, our method can resolve the problem during the production of the POMs based on interference principle. Information associated with the original image is smoothed away by modulation of the random POM. Illegal deciphers cannot retrieve the primitive image using only one or two of the POMs. Incorporated with the linear phase blend operation, our method can provide higher robustness against brute force attacks. Simulation results are presented to support the validity and feasibility of our method.

  14. Circuit Implementation, Synchronization of Multistability, and Image Encryption of a Four-Wing Memristive Chaotic System

    Directory of Open Access Journals (Sweden)

    Guangya Peng

    2018-01-01

    Full Text Available The four-wing memristive chaotic system used in synchronization is applied to secure communication which can increase the difficulty of deciphering effectively and enhance the security of information. In this paper, a novel four-wing memristive chaotic system with an active cubic flux-controlled memristor is proposed based on a Lorenz-like circuit. Dynamical behaviors of the memristive system are illustrated in terms of Lyapunov exponents, bifurcation diagrams, coexistence Poincaré maps, coexistence phase diagrams, and attraction basins. Besides, the modular equivalent circuit of four-wing memristive system is designed and the corresponding results are observed to verify its accuracy and rationality. A nonlinear synchronization controller with exponential function is devised to realize synchronization of the coexistence of multiple attractors, and the synchronization control scheme is applied to image encryption to improve secret key space. More interestingly, considering different influence of multistability on encryption, the appropriate key is achieved to enhance the antideciphering ability.

  15. Asymmetric optical image encryption using Kolmogorov phase screens and equal modulus decomposition

    Science.gov (United States)

    Kumar, Ravi; Bhaduri, Basanta; Quan, Chenggen

    2017-11-01

    An asymmetric technique for optical image encryption is proposed using Kolmogorov phase screens (KPSs) and equal modulus decomposition (EMD). The KPSs are generated using the power spectral density of Kolmogorov turbulence. The input image is first randomized and then Fresnel propagated with distance d. Further, the output in the Fresnel domain is modulated with a random phase mask, and the gyrator transform (GT) of the modulated image is obtained with an angle α. The EMD is operated on the GT spectrum to get the complex images, Z1 and Z2. Among these, Z2 is reserved as a private key for decryption and Z1 is propagated through a medium consisting of four KPSs, located at specified distances, to get the final encrypted image. The proposed technique provides a large set of security keys and is robust against various potential attacks. Numerical simulation results validate the effectiveness and security of the proposed technique.

  16. A Reusable Software Copy Protection Using Hash Result and Asymetrical Encryption

    Directory of Open Access Journals (Sweden)

    Aswin Wibisurya

    2014-12-01

    Full Text Available Desktop application is one of the most popular types of application being used in computer due to the one time install simplicity and the quick accessibility from the moment the computer being turned on. Limitation of the copy and usage of desktop applications has long been an important issue to application providers. For security concerns, software copy protection is usually integrated with the application. However, developers seek to reuse the copy protection component of the software. This paper proposes an approach of reusable software copy protection which consists of a certificate validator on the client computer and a certificate generator on the server. The certificate validator integrity is protected using hashing result while all communications are encrypted using asymmetrical encryption to ensure the security of this approach.

  17. A light weight secure image encryption scheme based on chaos & DNA computing

    Directory of Open Access Journals (Sweden)

    Bhaskar Mondal

    2017-10-01

    Full Text Available This paper proposed a new light weight secure cryptographic scheme for secure image communication. In this scheme the plain image is permuted first using a sequence of pseudo random number (PRN and encrypted by DeoxyriboNucleic Acid (DNA computation. Two PRN sequences are generated by a Pseudo Random Number Generator (PRNG based on cross coupled chaotic logistic map using two sets of keys. The first PRN sequence is used for permuting the plain image whereas the second PRN sequence is used for generating random DNA sequence. The number of rounds of permutation and encryption may be variable to increase security. The scheme is proposed for gray label images but the scheme may be extended for color images and text data. Simulation results exhibit that the proposed scheme can defy any kind of attack.

  18. Low-power Implementation of an Encryption/Decryption System with Asynchronous Techniques

    Directory of Open Access Journals (Sweden)

    Nikos Sklavos

    2002-01-01

    Full Text Available An asynchronous VLSI implementation of the International Data Encryption Algorithm (IDEA is presented in this paper. In order to evaluate the asynchronous design a synchronous version of the algorithm was also designed. VHDL hardware description language was used in order to describe the algorithm. By using Synopsys commercial available tools the VHDL code was synthesized. After placing and routing both designs were fabricated with 0.6 μm CMOS technology. With a system clock of up to 8 MHz and a power supply of 5 V the two chips were tested and evaluated comparing with the software implementation of the IDEA algorithm. This new approach proves efficiently the lowest power consumption of the asynchronous implementation compared to the existing synchronous. Therefore, the asynchronous chip performs efficiently in Wireless Encryption Protocols and high speed networks.

  19. Secured Session-key Distribution using control Vector Encryption / Decryption Process

    International Nuclear Information System (INIS)

    Ismail Jabiullah, M.; Abdullah Al-Shamim; Khaleqdad Khan, ANM; Lutfar Rahman, M.

    2006-01-01

    Frequent key changes are very much desirable for the secret communications and are thus in high demand. A session-key distribution technique has been designed and implemented using the programming language C on which the communication between the end-users is encrypted is used for the duration of a logical connection. Each session-key is obtained from the key distribution center (KDC) over the same networking facilities used for end-user communication. The control vector is cryptographically coupled with the session-key at the time of key generation in the KDC. For this, the generated hash function, master key and the session-key are used for producing the encrypted session-key, which has to be transferred. All the operations have been performed using the C programming language. This process can be widely applicable to all sorts of electronic transactions online or offline; commercially and academically.(authors)

  20. Digital chaos-masked optical encryption scheme enhanced by two-dimensional key space

    Science.gov (United States)

    Liu, Ling; Xiao, Shilin; Zhang, Lu; Bi, Meihua; Zhang, Yunhao; Fang, Jiafei; Hu, Weisheng

    2017-09-01

    A digital chaos-masked optical encryption scheme is proposed and demonstrated. The transmitted signal is completely masked by interference chaotic noise in both bandwidth and amplitude with analog method via dual-drive Mach-Zehnder modulator (DDMZM), making the encrypted signal analog, noise-like and unrecoverable by post-processing techniques. The decryption process requires precise matches of both the amplitude and phase between the cancellation and interference chaotic noises, which provide a large two-dimensional key space with the help of optical interference cancellation technology. For 10-Gb/s 16-quadrature amplitude modulation (QAM) orthogonal frequency division multiplexing (OFDM) signal over the maximum transmission distance of 80 km without dispersion compensation or inline amplifier, the tolerable mismatch ranges of amplitude and phase/delay at the forward error correction (FEC) threshold of 3.8×10-3 are 0.44 dB and 0.08 ns respectively.

  1. Hot Spot Removal System: System description

    International Nuclear Information System (INIS)

    1997-09-01

    Hazardous wastes contaminated with radionuclides, chemicals, and explosives exist across the Department of Energy complex and need to be remediated due to environmental concerns. Currently, an opportunity is being developed to dramatically reduce remediation costs and to assist in the acceleration of schedules associated with these wastes by deploying a Hot Spot Removal System. Removing the hot spot from the waste site will remove risk driver(s) and enable another, more cost effective process/option/remedial alternative (i.e., capping) to be applied to the remainder of the site. The Hot Spot Removal System consists of a suite of technologies that will be utilized to locate and remove source terms. Components of the system can also be used in a variety of other cleanup activities. This Hot Spot Removal System Description document presents technologies that were considered for possible inclusion in the Hot Spot Removal System, technologies made available to the Hot Spot Removal System, industrial interest in the Hot Spot Removal System''s subsystems, the schedule required for the Hot Spot Removal System, the evaluation of the relevant technologies, and the recommendations for equipment and technologies as stated in the Plan section

  2. A proposed security technique based on watermarking and encryption for digital imaging and communications in medicine

    Directory of Open Access Journals (Sweden)

    Mohamed M. Abd-Eldayem

    2013-03-01

    Full Text Available Nowadays; modern Hospital Data Management Systems (HDMSs are applied in a computer network; in addition medicinal equipments produce medical images in a digital form. HDMS must store and exchange these images in a secured environment to provide image integrity and patient privacy. The reversible watermarking techniques can be used to provide the integrity and the privacy. In this paper, a security technique based on watermarking and encryption is proposed to be used for Digital Imaging and Communications in Medicine (DICOM. It provides patient authentication, information confidentiality and integrity based on reversible watermark. To achieve integrity service at the sender side; a hash value based on encrypted MD5 is determined from the image. And to satisfy the reversible feature; R–S-Vector is determined from the image and is compressed based on a Huffman compression algorithm. After that to provide confidentiality and authentication services: the compressed R–S-Vector, the hash value and patient ID are concatenated to form a watermark then this watermark is encrypted using AES encryption technique, finally the watermark is embedded inside the medical image. Experimental results prove that the proposed technique can provide patient authentication services, image integrity service and information confidentiality service with excellent efficiency. Concluded results for all tested DICOM medical images and natural images show the following: BER equals 0, both of SNR and PSNR are consistent and have large values, and MSE has low value; the average values of SNR, PSNR and MSE are 52 dB, 57 dB and 0.12 respectively. Therefore, watermarked images have high imperceptibility, invisibility and transparency. In addition, the watermark extracted from the image at the receiver side is identical to the watermark embedded into the image in the sender side; as a result, the proposed technique is totally reversible, and the embedded watermark does not

  3. A PERFORMANCE EVALUATION OF COMMON ENCRYPTION TECHNIQUES WITH SECURE WATERMARK SYSTEM (SWS)

    OpenAIRE

    Ashraf Odeh; Shadi R.Masadeh; Ahmad Azzazi

    2015-01-01

    Ciphering algorithms play a main role in information security systems. Therefore in this paper we are considering the important performance of these algorithms like CPU time consumption, memory usage and battery usage. This research tries to demonstrate a fair comparison between the most common algorithms and with a novel method called Secured Watermark System (SWS) in data encryption field according to CPU time, packet size and power consumption. It provides a comparison the most known algor...

  4. Error-free holographic frames encryption with CA pixel-permutation encoding algorithm

    Science.gov (United States)

    Li, Xiaowei; Xiao, Dan; Wang, Qiong-Hua

    2018-01-01

    The security of video data is necessary in network security transmission hence cryptography is technique to make video data secure and unreadable to unauthorized users. In this paper, we propose a holographic frames encryption technique based on the cellular automata (CA) pixel-permutation encoding algorithm. The concise pixel-permutation algorithm is used to address the drawbacks of the traditional CA encoding methods. The effectiveness of the proposed video encoding method is demonstrated by simulation examples.

  5. Decoding Generalized Reed-Solomon Codes and Its Application to RLCE Encryption Schemes

    OpenAIRE

    Wang, Yongge

    2017-01-01

    This paper compares the efficiency of various algorithms for implementing quantum resistant public key encryption scheme RLCE on 64-bit CPUs. By optimizing various algorithms for polynomial and matrix operations over finite fields, we obtained several interesting (or even surprising) results. For example, it is well known (e.g., Moenck 1976 \\cite{moenck1976practical}) that Karatsuba's algorithm outperforms classical polynomial multiplication algorithm from the degree 15 and above (practically...

  6. The Methods and Mechanisms for Access Control of Encrypted Data in Clouds

    Directory of Open Access Journals (Sweden)

    Sergey Vladimirovich Zapechnikov

    2013-09-01

    Full Text Available The paper is about the problem of data access control in clouds. The main mechanisms for access control of encrypted data in untrusted cloud environments are analyzed and described. The comparative analysis of access control algorithms and implementation issues are offered. The main practical result of research is a web-based (Wikipedia-like reference and information system devoted to the access control methods and mechanisms.

  7. Implementasi Pengenkripsian Dan Penyembunyian Data Menggunakan Tiny Encryption Algorithm Dan End Of File

    OpenAIRE

    Alfian, Muhammad

    2013-01-01

    Security and confidentiality of data is one important aspect of an information system. The information can be misused very large losses in high-profile cases such vital information confidential corporate, customer data banks and etc. Information security solutions in one of them can be used with cryptography. Cryptographic algorithms used in this study is a tiny encryption algorithm. Cryptographic data security attacks can always wear can occur, with this in mind the authors added security te...

  8. Cracking chaos-based encryption systems ruled by nonlinear time delay differential equations

    International Nuclear Information System (INIS)

    Udaltsov, Vladimir S.; Goedgebuer, Jean-Pierre; Larger, Laurent; Cuenot, Jean-Baptiste; Levy, Pascal; Rhodes, William T.

    2003-01-01

    We report that signal encoding with high-dimensional chaos produced by delayed feedback systems with a strong nonlinearity can be broken. We describe the procedure and illustrate the method with chaotic waveforms obtained from a strongly nonlinear optical system that we used previously to demonstrate signal encryption/decryption with chaos in wavelength. The method can be extended to any systems ruled by nonlinear time-delayed differential equations

  9. Fine-grained Database Field Search Using Attribute-Based Encryption for E-Healthcare Clouds.

    Science.gov (United States)

    Guo, Cheng; Zhuang, Ruhan; Jie, Yingmo; Ren, Yizhi; Wu, Ting; Choo, Kim-Kwang Raymond

    2016-11-01

    An effectively designed e-healthcare system can significantly enhance the quality of access and experience of healthcare users, including facilitating medical and healthcare providers in ensuring a smooth delivery of services. Ensuring the security of patients' electronic health records (EHRs) in the e-healthcare system is an active research area. EHRs may be outsourced to a third-party, such as a community healthcare cloud service provider for storage due to cost-saving measures. Generally, encrypting the EHRs when they are stored in the system (i.e. data-at-rest) or prior to outsourcing the data is used to ensure data confidentiality. Searchable encryption (SE) scheme is a promising technique that can ensure the protection of private information without compromising on performance. In this paper, we propose a novel framework for controlling access to EHRs stored in semi-trusted cloud servers (e.g. a private cloud or a community cloud). To achieve fine-grained access control for EHRs, we leverage the ciphertext-policy attribute-based encryption (CP-ABE) technique to encrypt tables published by hospitals, including patients' EHRs, and the table is stored in the database with the primary key being the patient's unique identity. Our framework can enable different users with different privileges to search on different database fields. Differ from previous attempts to secure outsourcing of data, we emphasize the control of the searches of the fields within the database. We demonstrate the utility of the scheme by evaluating the scheme using datasets from the University of California, Irvine.

  10. Using Mathematics to Make Computing on Encrypted Data Secure and Practical

    Science.gov (United States)

    2015-12-01

    Silverberg discovered and developed algorithms to solve some lattices problems under suitable conditions , and investigated the mathemati- cal foundations...require no analogous condition on ` and m. Along the way towards formulating and proving our main algorithms, we prove and use: Theorem 15. If L is an...preliminary decryption of the operands , for many sets of interesting operations. These special encryption functions we call ‘privacy homomorphisms’; they form

  11. THRIVE: threshold homomorphic encryption based secure and privacy preserving biometric verification system

    Science.gov (United States)

    Karabat, Cagatay; Kiraz, Mehmet Sabir; Erdogan, Hakan; Savas, Erkay

    2015-12-01

    In this paper, we introduce a new biometric verification and template protection system which we call THRIVE. The system includes novel enrollment and authentication protocols based on threshold homomorphic encryption where a private key is shared between a user and a verifier. In the THRIVE system, only encrypted binary biometric templates are stored in a database and verification is performed via homomorphically randomized templates, thus, original templates are never revealed during authentication. Due to the underlying threshold homomorphic encryption scheme, a malicious database owner cannot perform full decryption on encrypted templates of the users in the database. In addition, security of the THRIVE system is enhanced using a two-factor authentication scheme involving user's private key and biometric data. Using simulation-based techniques, the proposed system is proven secure in the malicious model. The proposed system is suitable for applications where the user does not want to reveal her biometrics to the verifier in plain form, but needs to prove her identity by using biometrics. The system can be used with any biometric modality where a feature extraction method yields a fixed size binary template and a query template is verified when its Hamming distance to the database template is less than a threshold. The overall connection time for the proposed THRIVE system is estimated to be 336 ms on average for 256-bit biometric templates on a desktop PC running with quad core 3.2 GHz CPUs at 10 Mbit/s up/down link connection speed. Consequently, the proposed system can be efficiently used in real-life applications.

  12. 7 CFR 28.415 - Low Middling Light Spotted Color.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Low Middling Light Spotted Color. 28.415 Section 28... Spotted Color. Low Middling Light Spotted Color is color which in spot or color, or both, is between Low Middling Color and Low Middling Spotted Color. ...

  13. 7 CFR 28.411 - Good Middling Light Spotted Color.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Good Middling Light Spotted Color. 28.411 Section 28... Light Spotted Color. Good Middling Light Spotted Color is color which in spot or color, or both, is between Good Middling Color and Good Middling Spotted Color. ...

  14. 7 CFR 28.413 - Middling Light Spotted Color.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Middling Light Spotted Color. 28.413 Section 28.413... Spotted Color. Middling Light Spotted Color is color which in spot or color, or both, is between Middling Color and Middling Spotted Color. ...

  15. 7 CFR 28.412 - Strict Middling Light Spotted Color.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Strict Middling Light Spotted Color. 28.412 Section 28... Light Spotted Color. Strict Middling Light Spotted Color is color which in spot or color, or both, is between Strict Middling Color and Strict Middling Spotted Color. ...

  16. An Improvement to a Multi-Client Searchable Encryption Scheme for Boolean Queries.

    Science.gov (United States)

    Jiang, Han; Li, Xue; Xu, Qiuliang

    2016-12-01

    The migration of e-health systems to the cloud computing brings huge benefits, as same as some security risks. Searchable Encryption(SE) is a cryptography encryption scheme that can protect the confidentiality of data and utilize the encrypted data at the same time. The SE scheme proposed by Cash et al. in Crypto2013 and its follow-up work in CCS2013 are most practical SE Scheme that support Boolean queries at present. In their scheme, the data user has to generate the search tokens by the counter number one by one and interact with server repeatedly, until he meets the correct one, or goes through plenty of tokens to illustrate that there is no search result. In this paper, we make an improvement to their scheme. We allow server to send back some information and help the user to generate exact search token in the search phase. In our scheme, there are only two round interaction between server and user, and the search token has [Formula: see text] elements, where n is the keywords number in query expression, and [Formula: see text] is the minimum documents number that contains one of keyword in query expression, and the computation cost of server is [Formula: see text] modular exponentiation operation.

  17. Practical somewhat-secure quantum somewhat-homomorphic encryption with coherent states

    Science.gov (United States)

    Tan, Si-Hui; Ouyang, Yingkai; Rohde, Peter P.

    2018-04-01

    We present a scheme for implementing homomorphic encryption on coherent states encoded using phase-shift keys. The encryption operations require only rotations in phase space, which commute with computations in the code space performed via passive linear optics, and with generalized nonlinear phase operations that are polynomials of the photon-number operator in the code space. This encoding scheme can thus be applied to any computation with coherent-state inputs, and the computation proceeds via a combination of passive linear optics and generalized nonlinear phase operations. An example of such a computation is matrix multiplication, whereby a vector representing coherent-state amplitudes is multiplied by a matrix representing a linear optics network, yielding a new vector of coherent-state amplitudes. By finding an orthogonal partitioning of the support of our encoded states, we quantify the security of our scheme via the indistinguishability of the encrypted code words. While we focus on coherent-state encodings, we expect that this phase-key encoding technique could apply to any continuous-variable computation scheme where the phase-shift operator commutes with the computation.

  18. Fourier-Mellin moment-based intertwining map for image encryption

    Science.gov (United States)

    Kaur, Manjit; Kumar, Vijay

    2018-03-01

    In this paper, a robust image encryption technique that utilizes Fourier-Mellin moments and intertwining logistic map is proposed. Fourier-Mellin moment-based intertwining logistic map has been designed to overcome the issue of low sensitivity of an input image. Multi-objective Non-Dominated Sorting Genetic Algorithm (NSGA-II) based on Reinforcement Learning (MNSGA-RL) has been used to optimize the required parameters of intertwining logistic map. Fourier-Mellin moments are used to make the secret keys more secure. Thereafter, permutation and diffusion operations are carried out on input image using secret keys. The performance of proposed image encryption technique has been evaluated on five well-known benchmark images and also compared with seven well-known existing encryption techniques. The experimental results reveal that the proposed technique outperforms others in terms of entropy, correlation analysis, a unified average changing intensity and the number of changing pixel rate. The simulation results reveal that the proposed technique provides high level of security and robustness against various types of attacks.

  19. Privacy protection in HealthGrid: distributing encryption management over the VO.

    Science.gov (United States)

    Torres, Erik; de Alfonso, Carlos; Blanquer, Ignacio; Hernández, Vicente

    2006-01-01

    Grid technologies have proven to be very successful in tackling challenging problems in which data access and processing is a bottleneck. Notwithstanding the benefits that Grid technologies could have in Health applications, privacy leakages of current DataGrid technologies due to the sharing of data in VOs and the use of remote resources, compromise its widespreading. Privacy control for Grid technology has become a key requirement for the adoption of Grids in the Healthcare sector. Encrypted storage of confidential data effectively reduces the risk of disclosure. A self-enforcing scheme for encrypted data storage can be achieved by combining Grid security systems with distributed key management and classical cryptography techniques. Virtual Organizations, as the main unit of user management in Grid, can provide a way to organize key sharing, access control lists and secure encryption management. This paper provides programming models and discusses the value, costs and behavior of such a system implemented on top of one of the latest Grid middlewares. This work is partially funded by the Spanish Ministry of Science and Technology in the frame of the project Investigación y Desarrollo de Servicios GRID: Aplicación a Modelos Cliente-Servidor, Colaborativos y de Alta Productividad, with reference TIC2003-01318.

  20. A DNA-Inspired Encryption Methodology for Secure, Mobile Ad Hoc Networks

    Science.gov (United States)

    Shaw, Harry

    2012-01-01

    Users are pushing for greater physical mobility with their network and Internet access. Mobile ad hoc networks (MANET) can provide an efficient mobile network architecture, but security is a key concern. A figure summarizes differences in the state of network security for MANET and fixed networks. MANETs require the ability to distinguish trusted peers, and tolerate the ingress/egress of nodes on an unscheduled basis. Because the networks by their very nature are mobile and self-organizing, use of a Public Key Infra structure (PKI), X.509 certificates, RSA, and nonce ex changes becomes problematic if the ideal of MANET is to be achieved. Molecular biology models such as DNA evolution can provide a basis for a proprietary security architecture that achieves high degrees of diffusion and confusion, and resistance to cryptanalysis. A proprietary encryption mechanism was developed that uses the principles of DNA replication and steganography (hidden word cryptography) for confidentiality and authentication. The foundation of the approach includes organization of coded words and messages using base pairs organized into genes, an expandable genome consisting of DNA-based chromosome keys, and a DNA-based message encoding, replication, and evolution and fitness. In evolutionary computing, a fitness algorithm determines whether candidate solutions, in this case encrypted messages, are sufficiently encrypted to be transmitted. The technology provides a mechanism for confidential electronic traffic over a MANET without a PKI for authenticating users.