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&...

A Methodology for Retrieving Information from Malware Encrypted Output Files: Brazilian Case Studies

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Nelson Uto

2013-04-01

Full Text Available This article presents and explains a methodology based on cryptanalytic and reverse engineering techniques that can be employed to quickly recover information from encrypted files generated by malware. The objective of the methodology is to minimize the effort with static and dynamic analysis, by using cryptanalysis and related knowledge as much as possible. In order to illustrate how it works, we present three case studies, taken from a big Brazilian company that was victimized by directed attacks focused on stealing information from a special purpose hardware they use in their environment.

Efficient Dynamic Searchable Encryption with Forward Privacy

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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.

Information encryption systems based on Boolean functions

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Aureliu Zgureanu

2011-02-01

Full Text Available An information encryption system based on Boolean functions is proposed. Information processing is done using multidimensional matrices, performing logical operations with these matrices. At the basis of ensuring high level security of the system the complexity of solving the problem of building systems of Boolean functions that depend on many variables (tens and hundreds is set. Such systems represent the private key. It varies both during the encryption and decryption of information, and during the transition from one message to another.

Proof of cipher text ownership based on convergence encryption

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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.

System for Information Encryption Implementing Several Chaotic Orbits

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Jiménez-Rodríguez Maricela

2015-07-01

Full Text Available This article proposes a symmetric encryption algorithm that takes, as input value, the original information of length L, that when encoded, generates the ciphertext of greater length LM. A chaotic discrete system (logistic map is implemented to generate 3 different orbits: the first is used for applying a diffusion technique in order to mix the original data, the second orbit is combined with the mixed information and increases the length of L to LM, and with the third orbit, the confusion technique is implemented. The encryption algorithm was applied to encode an image which is then totally recovered by the keys used to encrypt and his respective, decrypt algorithm. The algorithm can encode any information, just dividing into 8 bits, it can cover the requirements for high level security, it uses 7 keys to encrypt and provides good encryption speed

Enhanced K-means clustering with encryption on cloud

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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

Digital Sound Encryption with Logistic Map and Number Theoretic Transform

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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.

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

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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.

An Efficient Quantum Somewhat Homomorphic Symmetric Searchable Encryption

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Sun, Xiaoqiang; Wang, Ting; Sun, Zhiwei; Wang, Ping; Yu, Jianping; Xie, Weixin

2017-04-01

In 2009, Gentry first introduced an ideal lattices fully homomorphic encryption (FHE) scheme. Later, based on the approximate greatest common divisor problem, learning with errors problem or learning with errors over rings problem, FHE has developed rapidly, along with the low efficiency and computational security. Combined with quantum mechanics, Liang proposed a symmetric quantum somewhat homomorphic encryption (QSHE) scheme based on quantum one-time pad, which is unconditional security. And it was converted to a quantum fully homomorphic encryption scheme, whose evaluation algorithm is based on the secret key. Compared with Liang's QSHE scheme, we propose a more efficient QSHE scheme for classical input states with perfect security, which is used to encrypt the classical message, and the secret key is not required in the evaluation algorithm. Furthermore, an efficient symmetric searchable encryption (SSE) scheme is constructed based on our QSHE scheme. SSE is important in the cloud storage, which allows users to offload search queries to the untrusted cloud. Then the cloud is responsible for returning encrypted files that match search queries (also encrypted), which protects users' privacy.

System for processing an encrypted instruction stream in hardware

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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.

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

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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.

Color Image Encryption Algorithm Based on TD-ERCS System and Wavelet Neural Network

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Kun Zhang

2015-01-01

Full Text Available In order to solve the security problem of transmission image across public networks, a new image encryption algorithm based on TD-ERCS system and wavelet neural network is proposed in this paper. According to the permutation process and the binary XOR operation from the chaotic series by producing TD-ERCS system and wavelet neural network, it can achieve image encryption. This encryption algorithm is a reversible algorithm, and it can achieve original image in the rule inverse process of encryption algorithm. Finally, through computer simulation, the experiment results show that the new chaotic encryption algorithm based on TD-ERCS system and wavelet neural network is valid and has higher security.

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

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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.

Image compression-encryption scheme based on hyper-chaotic system and 2D compressive sensing

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Zhou, Nanrun; Pan, Shumin; Cheng, Shan; Zhou, Zhihong

2016-08-01

Most image encryption algorithms based on low-dimensional chaos systems bear security risks and suffer encryption data expansion when adopting nonlinear transformation directly. To overcome these weaknesses and reduce the possible transmission burden, an efficient image compression-encryption scheme based on hyper-chaotic system and 2D compressive sensing is proposed. The original image is measured by the measurement matrices in two directions to achieve compression and encryption simultaneously, and then the resulting image is re-encrypted by the cycle shift operation controlled by a hyper-chaotic system. Cycle shift operation can change the values of the pixels efficiently. The proposed cryptosystem decreases the volume of data to be transmitted and simplifies the keys distribution simultaneously as a nonlinear encryption system. Simulation results verify the validity and the reliability of the proposed algorithm with acceptable compression and security performance.

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

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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.

Simultaneous transmission for an encrypted image and a double random-phase encryption key

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Yuan, Sheng; Zhou, Xin; Li, Da-Hai; Zhou, Ding-Fu

2007-06-01

We propose a method to simultaneously transmit double random-phase encryption key and an encrypted image by making use of the fact that an acceptable decryption result can be obtained when only partial data of the encrypted image have been taken in the decryption process. First, the original image data are encoded as an encrypted image by a double random-phase encryption technique. Second, a double random-phase encryption key is encoded as an encoded key by the Rivest-Shamir-Adelman (RSA) public-key encryption algorithm. Then the amplitude of the encrypted image is modulated by the encoded key to form what we call an encoded image. Finally, the encoded image that carries both the encrypted image and the encoded key is delivered to the receiver. Based on such a method, the receiver can have an acceptable result and secure transmission can be guaranteed by the RSA cipher system.

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

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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.

Steganographic optical image encryption system based on reversible data hiding and double random phase encoding

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Chuang, Cheng-Hung; Chen, Yen-Lin

2013-02-01

This study presents a steganographic optical image encryption system based on reversible data hiding and double random phase encoding (DRPE) techniques. Conventional optical image encryption systems can securely transmit valuable images using an encryption method for possible application in optical transmission systems. The steganographic optical image encryption system based on the DRPE technique has been investigated to hide secret data in encrypted images. However, the DRPE techniques vulnerable to attacks and many of the data hiding methods in the DRPE system can distort the decrypted images. The proposed system, based on reversible data hiding, uses a JBIG2 compression scheme to achieve lossless decrypted image quality and perform a prior encryption process. Thus, the DRPE technique enables a more secured optical encryption process. The proposed method extracts and compresses the bit planes of the original image using the lossless JBIG2 technique. The secret data are embedded in the remaining storage space. The RSA algorithm can cipher the compressed binary bits and secret data for advanced security. Experimental results show that the proposed system achieves a high data embedding capacity and lossless reconstruction of the original images.

Dynamic video encryption algorithm for H.264/AVC based on a spatiotemporal chaos system.

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Xu, Hui; Tong, Xiao-Jun; Zhang, Miao; Wang, Zhu; Li, Ling-Hao

2016-06-01

Video encryption schemes mostly employ the selective encryption method to encrypt parts of important and sensitive video information, aiming to ensure the real-time performance and encryption efficiency. The classic block cipher is not applicable to video encryption due to the high computational overhead. In this paper, we propose the encryption selection control module to encrypt video syntax elements dynamically which is controlled by the chaotic pseudorandom sequence. A novel spatiotemporal chaos system and binarization method is used to generate a key stream for encrypting the chosen syntax elements. The proposed scheme enhances the resistance against attacks through the dynamic encryption process and high-security stream cipher. Experimental results show that the proposed method exhibits high security and high efficiency with little effect on the compression ratio and time cost.

Encrypted IP video communication system

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Bogdan, Apetrechioaie; Luminiţa, Mateescu

2010-11-01

Digital video transmission is a permanent subject of development, research and improvement. This field of research has an exponentially growing market in civil, surveillance, security and military aplications. A lot of solutions: FPGA, ASIC, DSP have been used for this purpose. The paper presents the implementation of an encrypted, IP based, video communication system having a competitive performance/cost ratio .

DATA SECURITY IN LOCAL AREA NETWORK BASED ON FAST ENCRYPTION ALGORITHM

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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.

Cryptanalysis of the public key encryption based on multiple chaotic systems

International Nuclear Information System (INIS)

Zhang Linhua

2008-01-01

Recently, Ranjan proposed a novel public key encryption technique based on multiple chaotic systems [Phys Lett 2005;95]. Unfortunately, Wang soon gave a successful attack on its special case based on Parseval's theorem [Wang K, Pei W, Zhou L, et al. Security of public key encryption technique based on multiple chaotic system. Phys Lett A, in press]. In this letter, we give an improved example which can avoid the attack and point out that Wang cannot find the essential drawback of the technique. However, further experimental result shows Ruanjan's encryption technique is inefficient, and detailed theoretic analysis shows that the complexity to break the cryptosystem is overestimated

A Novel Fast and Secure Approach for Voice Encryption Based on DNA Computing

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Kakaei Kate, Hamidreza; Razmara, Jafar; Isazadeh, Ayaz

2018-06-01

Today, in the world of information communication, voice information has a particular importance. One way to preserve voice data from attacks is voice encryption. The encryption algorithms use various techniques such as hashing, chaotic, mixing, and many others. In this paper, an algorithm is proposed for voice encryption based on three different schemes to increase flexibility and strength of the algorithm. The proposed algorithm uses an innovative encoding scheme, the DNA encryption technique and a permutation function to provide a secure and fast solution for voice encryption. The algorithm is evaluated based on various measures including signal to noise ratio, peak signal to noise ratio, correlation coefficient, signal similarity and signal frequency content. The results demonstrate applicability of the proposed method in secure and fast encryption of voice files

Implementation of Rivest Shamir Adleman Algorithm (RSA) and Vigenere Cipher In Web Based Information System

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Aryanti, Aryanti; Mekongga, Ikhthison

2018-02-01

Data security and confidentiality is one of the most important aspects of information systems at the moment. One attempt to secure data such as by using cryptography. In this study developed a data security system by implementing the cryptography algorithm Rivest, Shamir Adleman (RSA) and Vigenere Cipher. The research was done by combining Rivest, Shamir Adleman (RSA) and Vigenere Cipher cryptographic algorithms to document file either word, excel, and pdf. This application includes the process of encryption and decryption of data, which is created by using PHP software and my SQL. Data encryption is done on the transmit side through RSA cryptographic calculations using the public key, then proceed with Vigenere Cipher algorithm which also uses public key. As for the stage of the decryption side received by using the Vigenere Cipher algorithm still use public key and then the RSA cryptographic algorithm using a private key. Test results show that the system can encrypt files, decrypt files and transmit files. Tests performed on the process of encryption and decryption of files with different file sizes, file size affects the process of encryption and decryption. The larger the file size the longer the process of encryption and decryption.

Image compression-encryption algorithms by combining hyper-chaotic system with discrete fractional random transform

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Gong, Lihua; Deng, Chengzhi; Pan, Shumin; Zhou, Nanrun

2018-07-01

Based on hyper-chaotic system and discrete fractional random transform, an image compression-encryption algorithm is designed. The original image is first transformed into a spectrum by the discrete cosine transform and the resulting spectrum is compressed according to the method of spectrum cutting. The random matrix of the discrete fractional random transform is controlled by a chaotic sequence originated from the high dimensional hyper-chaotic system. Then the compressed spectrum is encrypted by the discrete fractional random transform. The order of DFrRT and the parameters of the hyper-chaotic system are the main keys of this image compression and encryption algorithm. The proposed algorithm can compress and encrypt image signal, especially can encrypt multiple images once. To achieve the compression of multiple images, the images are transformed into spectra by the discrete cosine transform, and then the spectra are incised and spliced into a composite spectrum by Zigzag scanning. Simulation results demonstrate that the proposed image compression and encryption algorithm is of high security and good compression performance.

Improved decryption quality and security of a joint transform correlator-based encryption system

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

2013-02-01

Some image encryption systems based on modified double random phase encoding and joint transform correlator architecture produce low quality decrypted images and are vulnerable to a variety of attacks. In this work, we analyse the algorithm of some reported methods that optically implement the double random phase encryption in a joint transform correlator. We show that it is possible to significantly improve the quality of the decrypted image by introducing a simple nonlinear operation in the encrypted function that contains the joint power spectrum. This nonlinearity also makes the system more resistant to chosen-plaintext attacks. We additionally explore the system resistance against this type of attack when a variety of probability density functions are used to generate the two random phase masks of the encryption-decryption process. Numerical results are presented and discussed.

Vehicle security encryption based on unlicensed encryption

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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.

Towards Provably Secure Efficiently Searchable Encryption

NARCIS (Netherlands)

Sedghi, S.

2012-01-01

Traditional encryption systems are designed in such a way that either the whole data is decrypted, if the encryption and decryption keys match, or nothing is decrypted otherwise. However, there are applications that require a more flexible encryption system which supports decrypting data partially.

Cryptanalysis of a discrete-time synchronous chaotic encryption system

International Nuclear Information System (INIS)

Arroyo, David; Alvarez, Gonzalo; Li Shujun; Li Chengqing; Nunez, Juana

2008-01-01

Recently a chaotic cryptosystem based on discrete-time synchronization has been proposed. Some weaknesses of that new encryption system are addressed and exploited in order to successfully cryptanalyze the system

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

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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.

Encryption Technology based on Human Biometrics

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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.

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)

Efficient image or video encryption based on spatiotemporal chaos system

International Nuclear Information System (INIS)

Lian Shiguo

2009-01-01

In this paper, an efficient image/video encryption scheme is constructed based on spatiotemporal chaos system. The chaotic lattices are used to generate pseudorandom sequences and then encrypt image blocks one by one. By iterating chaotic maps for certain times, the generated pseudorandom sequences obtain high initial-value sensitivity and good randomness. The pseudorandom-bits in each lattice are used to encrypt the Direct Current coefficient (DC) and the signs of the Alternating Current coefficients (ACs). Theoretical analysis and experimental results show that the scheme has good cryptographic security and perceptual security, and it does not affect the compression efficiency apparently. These properties make the scheme a suitable choice for practical applications.

Quantum Color Image Encryption Algorithm Based on A Hyper-Chaotic System and Quantum Fourier Transform

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Tan, Ru-Chao; Lei, Tong; Zhao, Qing-Min; Gong, Li-Hua; Zhou, Zhi-Hong

2016-12-01

To improve the slow processing speed of the classical image encryption algorithms and enhance the security of the private color images, a new quantum color image encryption algorithm based on a hyper-chaotic system is proposed, in which the sequences generated by the Chen's hyper-chaotic system are scrambled and diffused with three components of the original color image. Sequentially, the quantum Fourier transform is exploited to fulfill the encryption. Numerical simulations show that the presented quantum color image encryption algorithm possesses large key space to resist illegal attacks, sensitive dependence on initial keys, uniform distribution of gray values for the encrypted image and weak correlation between two adjacent pixels in the cipher-image.

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

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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.

Implementation of Rivest Shamir Adleman Algorithm (RSA and Vigenere Cipher In Web Based Information System

Directory of Open Access Journals (Sweden)

Aryanti Aryanti

2018-01-01

Full Text Available Data security and confidentiality is one of the most important aspects of information systems at the moment. One attempt to secure data such as by using cryptography. In this study developed a data security system by implementing the cryptography algorithm Rivest, Shamir Adleman (RSA and Vigenere Cipher. The research was done by combining Rivest, Shamir Adleman (RSA and Vigenere Cipher cryptographic algorithms to document file either word, excel, and pdf. This application includes the process of encryption and decryption of data, which is created by using PHP software and my SQL. Data encryption is done on the transmit side through RSA cryptographic calculations using the public key, then proceed with Vigenere Cipher algorithm which also uses public key. As for the stage of the decryption side received by using the Vigenere Cipher algorithm still use public key and then the RSA cryptographic algorithm using a private key. Test results show that the system can encrypt files, decrypt files and transmit files. Tests performed on the process of encryption and decryption of files with different file sizes, file size affects the process of encryption and decryption. The larger the file size the longer the process of encryption and decryption.

A new image encryption algorithm based on the fractional-order hyperchaotic Lorenz system

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Wang, Zhen; Huang, Xia; Li, Yu-Xia; Song, Xiao-Na

2013-01-01

We propose a new image encryption algorithm on the basis of the fractional-order hyperchaotic Lorenz system. While in the process of generating a key stream, the system parameters and the derivative order are embedded in the proposed algorithm to enhance the security. Such an algorithm is detailed in terms of security analyses, including correlation analysis, information entropy analysis, run statistic analysis, mean-variance gray value analysis, and key sensitivity analysis. The experimental results demonstrate that the proposed image encryption scheme has the advantages of large key space and high security for practical image encryption.

Decryption-decompression of AES protected ZIP files on GPUs

Science.gov (United States)

Duong, Tan Nhat; Pham, Phong Hong; Nguyen, Duc Huu; Nguyen, Thuy Thanh; Le, Hung Duc

2011-10-01

AES is a strong encryption system, so decryption-decompression of AES encrypted ZIP files requires very large computing power and techniques of reducing the password space. This makes implementations of techniques on common computing system not practical. In [1], we reduced the original very large password search space to a much smaller one which surely containing the correct password. Based on reduced set of passwords, in this paper, we parallel decryption, decompression and plain text recognition for encrypted ZIP files by using CUDA computing technology on graphics cards GeForce GTX295 of NVIDIA, to find out the correct password. The experimental results have shown that the speed of decrypting, decompressing, recognizing plain text and finding out the original password increases about from 45 to 180 times (depends on the number of GPUs) compared to sequential execution on the Intel Core 2 Quad Q8400 2.66 GHz. These results have demonstrated the potential applicability of GPUs in this cryptanalysis field.

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.

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.

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.

Image encryption based on nonlinear encryption system and public-key cryptography

Science.gov (United States)

Zhao, Tieyu; Ran, Qiwen; Chi, Yingying

2015-03-01

Recently, optical asymmetric cryptosystem (OACS) has became the focus of discussion and concern of researchers. Some researchers pointed out that OACS was not tenable because of misunderstanding the concept of asymmetric cryptosystem (ACS). We propose an improved cryptosystem using RSA public-key algorithm based on existing OACS and the new system conforms to the basic agreement of public key cryptosystem. At the beginning of the encryption process, the system will produce an independent phase matrix and allocate the input image, which also conforms to one-time pad cryptosystem. The simulation results show that the validity of the improved cryptosystem and the high robustness against attack scheme using phase retrieval technique.

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.

Holographic memories with encryption-selectable function

Science.gov (United States)

Su, Wei-Chia; Lee, Xuan-Hao

2006-03-01

Volume holographic storage has received increasing attention owing to its potential high storage capacity and access rate. In the meanwhile, encrypted holographic memory using random phase encoding technique is attractive for an optical community due to growing demand for protection of information. In this paper, encryption-selectable holographic storage algorithms in LiNbO 3 using angular multiplexing are proposed and demonstrated. Encryption-selectable holographic memory is an advance concept of security storage for content protection. It offers more flexibility to encrypt the data or not optionally during the recording processes. In our system design, the function of encryption and non-encryption storage is switched by a random phase pattern and a uniform phase pattern. Based on a 90-degree geometry, the input patterns including the encryption and non-encryption storage are stored via angular multiplexing with reference plane waves at different incident angles. Image is encrypted optionally by sliding the ground glass into one of the recording waves or removing it away in each exposure. The ground glass is a key for encryption. Besides, it is also an important key available for authorized user to decrypt the encrypted information.

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

Generalized formulation of an encryption system based on a joint transform correlator and fractional Fourier transform

International Nuclear Information System (INIS)

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

2014-01-01

We propose a generalization of the encryption system based on double random phase encoding (DRPE) and a joint transform correlator (JTC), from the Fourier domain to the fractional Fourier domain (FrFD) by using the fractional Fourier operators, such as the fractional Fourier transform (FrFT), fractional traslation, fractional convolution and fractional correlation. Image encryption systems based on a JTC architecture in the FrFD usually produce low quality decrypted images. In this work, we present two approaches to improve the quality of the decrypted images, which are based on nonlinear processing applied to the encrypted function (that contains the joint fractional power spectrum, JFPS) and the nonzero-order JTC in the FrFD. When the two approaches are combined, the quality of the decrypted image is higher. In addition to the advantages introduced by the implementation of the DRPE using a JTC, we demonstrate that the proposed encryption system in the FrFD preserves the shift-invariance property of the JTC-based encryption system in the Fourier domain, with respect to the lateral displacement of both the key random mask in the decryption process and the retrieval of the primary image. The feasibility of this encryption system is verified and analyzed by computer simulations. (paper)

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.

Bit-level quantum color image encryption scheme with quantum cross-exchange operation and hyper-chaotic system

Science.gov (United States)

Zhou, Nanrun; Chen, Weiwei; Yan, Xinyu; Wang, Yunqian

2018-06-01

In order to obtain higher encryption efficiency, a bit-level quantum color image encryption scheme by exploiting quantum cross-exchange operation and a 5D hyper-chaotic system is designed. Additionally, to enhance the scrambling effect, the quantum channel swapping operation is employed to swap the gray values of corresponding pixels. The proposed color image encryption algorithm has larger key space and higher security since the 5D hyper-chaotic system has more complex dynamic behavior, better randomness and unpredictability than those based on low-dimensional hyper-chaotic systems. Simulations and theoretical analyses demonstrate that the presented bit-level quantum color image encryption scheme outperforms its classical counterparts in efficiency and security.

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)

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.

Dynamic encryption method

DEFF Research Database (Denmark)

2013-01-01

algorithm for on provision of a specific key, decrypting cipher data and reproduce plain data; encrypting the first data package comprising plain data, using a first encryption program implementing the first encryption algorithm of said first encryption technique, creating a first encrypted data package...... comprising cipher data; obtaining a first decryption program; and transmitting said first decryption program and said first encrypted data package to a receiver, wherein the first decryption, upon provision of the specific key and the first encrypted data package, will decrypt the cipher data in the first...

Improved decryption quality and security of a joint transform correlator-based encryption system

International Nuclear Information System (INIS)

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

2013-01-01

Some image encryption systems based on modified double random phase encoding and joint transform correlator architecture produce low quality decrypted images and are vulnerable to a variety of attacks. In this work, we analyse the algorithm of some reported methods that optically implement the double random phase encryption in a joint transform correlator. We show that it is possible to significantly improve the quality of the decrypted image by introducing a simple nonlinear operation in the encrypted function that contains the joint power spectrum. This nonlinearity also makes the system more resistant to chosen-plaintext attacks. We additionally explore the system resistance against this type of attack when a variety of probability density functions are used to generate the two random phase masks of the encryption–decryption process. Numerical results are presented and discussed. (paper)

An improved Huffman coding with encryption for Radio Data System (RDS) for smart transportation

Science.gov (United States)

Wu, C. H.; Tseng, Kuo-Kun; Ng, C. K.; Ho, G. T. S.; Zeng, Fu-Fu; Tse, Y. K.

2018-02-01

As the development of Radio Data System (RDS) technology and its applications are getting more and more attention and promotion, people concern their personal privacy and communication efficiency, and therefore compression and encryption technologies are being more important for transferring RDS data. Unlike most of the current approaches which contain two stages, compression and encryption, we proposed a new algorithm called Swapped Huffman Table (SHT) based on Huffman algorithm to realise compression and encryption in a single process. In this paper, a good performance for both compression and encryption is obtained and a possible application of RDS with the proposed algorithm in smart transportation is illustrated.

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

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.

SMS Security System on Mobile Devices Using Tiny Encryption Algorithm

Science.gov (United States)

Novelan, M. S.; Husein, A. M.; Harahap, M.; Aisyah, S.

2018-04-01

The development of telecommunications technology is so rapid has given such great benefits. With the telecommunication technology, distance and time no longer be a significant obstacle. One of the results of telecommunications technology that is well known is the Short Message Service. In this study developed an application on the mobile phone to modify the SMS message into ciphertext so that the information content of the SMS is not known by others. SMS delivery system for encrypting messages into ciphertext using a key that is entered by the sender then sends to the destination number. SMS reception system to decrypt it to others via SMS without the fear of information from these messages will be known by others. The method used in the system encrypt and decrypt the message is the algorithm Tiny Encryption Algorithm and implemented using the Java programming language. JDK 1.7 as the Java programming language ciphertext into plaintext using the key entered by the receiver and displays the original message to the recipient. This application can be used by someone who wants to send a confidential information and the Java compiler. Eclipse, a Java SDK and the Android SDK as a Java source code editor.

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)

Improvement of Networked Control Systems Performance Using a New Encryption Algorithm

Directory of Open Access Journals (Sweden)

Seyed Ali Mesbahifard

2014-07-01

Full Text Available Networked control systems are control systems which controllers and plants are connected via telecommunication network. One of the most important challenges in networked control systems is the problem of network time delay. Increasing of time delay may affect on control system performance extremely. Other important issue in networked control systems is the security problems. Since it is possible that unknown people access to network especially Internet, the probability of terrible attacks such as deception attacks is greater, therefore presentation of methods which could decrease time delay and increase system immunity are desired. In this paper a symmetric encryption with low data volume against deception attacks is proposed. This method has high security and low time delay rather than the other encryption algorithms and could improve the control system performance against deception attacks.

A Parallel Encryption Algorithm Based on Piecewise Linear Chaotic Map

Directory of Open Access Journals (Sweden)

Xizhong Wang

2013-01-01

Full Text Available We introduce a parallel chaos-based encryption algorithm for taking advantage of multicore processors. The chaotic cryptosystem is generated by the piecewise linear chaotic map (PWLCM. The parallel algorithm is designed with a master/slave communication model with the Message Passing Interface (MPI. The algorithm is suitable not only for multicore processors but also for the single-processor architecture. The experimental results show that the chaos-based cryptosystem possesses good statistical properties. The parallel algorithm provides much better performance than the serial ones and would be useful to apply in encryption/decryption file with large size or multimedia.

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.

Phase-Image Encryption Based on 3D-Lorenz Chaotic System and Double Random Phase Encoding

Science.gov (United States)

Sharma, Neha; Saini, Indu; Yadav, AK; Singh, Phool

2017-12-01

In this paper, an encryption scheme for phase-images based on 3D-Lorenz chaotic system in Fourier domain under the 4f optical system is presented. The encryption scheme uses a random amplitude mask in the spatial domain and a random phase mask in the frequency domain. Its inputs are phase-images, which are relatively more secure as compared to the intensity images because of non-linearity. The proposed scheme further derives its strength from the use of 3D-Lorenz transform in the frequency domain. Although the experimental setup for optical realization of the proposed scheme has been provided, the results presented here are based on simulations on MATLAB. It has been validated for grayscale images, and is found to be sensitive to the encryption parameters of the Lorenz system. The attacks analysis shows that the key-space is large enough to resist brute-force attack, and the scheme is also resistant to the noise and occlusion attacks. Statistical analysis and the analysis based on correlation distribution of adjacent pixels have been performed to test the efficacy of the encryption scheme. The results have indicated that the proposed encryption scheme possesses a high level of security.

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.

Image encryption based on a delayed fractional-order chaotic logistic system

Science.gov (United States)

Wang, Zhen; Huang, Xia; Li, Ning; Song, Xiao-Na

2012-05-01

A new image encryption scheme is proposed based on a delayed fractional-order chaotic logistic system. In the process of generating a key stream, the time-varying delay and fractional derivative are embedded in the proposed scheme to improve the security. Such a scheme is described in detail with security analyses including correlation analysis, information entropy analysis, run statistic analysis, mean-variance gray value analysis, and key sensitivity analysis. Experimental results show that the newly proposed image encryption scheme possesses high security.

Image encryption based on a delayed fractional-order chaotic logistic system

International Nuclear Information System (INIS)

Wang Zhen; Li Ning; Huang Xia; Song Xiao-Na

2012-01-01

A new image encryption scheme is proposed based on a delayed fractional-order chaotic logistic system. In the process of generating a key stream, the time-varying delay and fractional derivative are embedded in the proposed scheme to improve the security. Such a scheme is described in detail with security analyses including correlation analysis, information entropy analysis, run statistic analysis, mean-variance gray value analysis, and key sensitivity analysis. Experimental results show that the newly proposed image encryption scheme possesses high security. (general)

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.

Integral transformations applied to image encryption

International Nuclear Information System (INIS)

Vilardy, Juan M.; Torres, Cesar O.; Perez, Ronal

2017-01-01

In this paper we consider the application of the integral transformations for image encryption through optical systems, a mathematical algorithm under Matlab platform using fractional Fourier transform (FrFT) and Random Phase Mask (RPM) for digital images encryption is implemented. The FrFT can be related to others integral transforms, such as: Fourier transform, Sine and Cosine transforms, Radial Hilbert transform, fractional Sine transform, fractional Cosine transform, fractional Hartley transform, fractional Wavelet transform and Gyrator transform, among other transforms. The encryption scheme is based on the use of the FrFT, the joint transform correlator and two RPMs, which provide security and robustness to the implemented security system. One of the RPMs used during encryption-decryption and the fractional order of the FrFT are the keys to improve security and make the system more resistant against security attacks. (paper)

SETI-EC: SETI Encryption Code

Science.gov (United States)

Heller, René

2018-03-01

The SETI Encryption code, written in Python, creates a message for use in testing the decryptability of a simulated incoming interstellar message. The code uses images in a portable bit map (PBM) format, then writes the corresponding bits into the message, and finally returns both a PBM image and a text (TXT) file of the entire message. The natural constants (c, G, h) and the wavelength of the message are defined in the first few lines of the code, followed by the reading of the input files and their conversion into 757 strings of 359 bits to give one page. Each header of a page, i.e. the little-endian binary code translation of the tempo-spatial yardstick, is calculated and written on-the-fly for each page.

77 FR 67290 - Basic Service Tier Encryption Compatibility Between Cable Systems and Consumer Electronics Equipment

Science.gov (United States)

2012-11-09

...-126] Basic Service Tier Encryption Compatibility Between Cable Systems and Consumer Electronics... between consumer electronics equipment (such as digital television sets) and newly encrypted cable service... Act''), Congress sought to make sure that consumer electronics equipment could receive cable...

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.

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,

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.

CryptoCache: A Secure Sharable File Cache for Roaming Users

DEFF Research Database (Denmark)

Jensen, Christian D.

2000-01-01

. Conventional distributed file systems cache everything locally or not at all; there is no possibility to cache files on nearby nodes.In this paper we present the design of a secure cache system called CryptoCache that allows roaming users to cache files on untrusted file hosting servers. The system allows...... flexible sharing of cached files among unauthenticated users, i.e. unlike most distributed file systems CryptoCache does not require a global authentication framework.Files are encrypted when they are transferred over the network and while stored on untrusted servers. The system uses public key......Small mobile computers are now sufficiently powerful to run many applications, but storage capacity remains limited so working files cannot be cached or stored locally. Even if files can be stored locally, the mobile device is not powerful enough to act as server in collaborations with other users...

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

Secure distributed key generation in attribute based encryption systems

NARCIS (Netherlands)

Pletea, D.; Sedghi, S.; Veeningen, M.; Petkovic, M.

2016-01-01

Nowadays usage of cloud computing is increasing in popularity and this raises new data protection challenges. In such distributed systems it is unrealistic to assume that the servers are fully trusted in enforcing the access policies. Attribute Based Encryption (ABE) is one of the solutions proposed

Encryption of Stereo Images after Compression by Advanced Encryption Standard (AES

Directory of Open Access Journals (Sweden)

Marwah k Hussien

2018-04-01

Full Text Available New partial encryption schemes are proposed, in which a secure encryption algorithm is used to encrypt only part of the compressed data. Partial encryption applied after application of image compression algorithm. Only 0.0244%-25% of the original data isencrypted for two pairs of dif-ferent grayscale imageswiththe size (256 ´ 256 pixels. As a result, we see a significant reduction of time in the stage of encryption and decryption. In the compression step, the Orthogonal Search Algorithm (OSA for motion estimation (the dif-ferent between stereo images is used. The resulting disparity vector and the remaining image were compressed by Discrete Cosine Transform (DCT, Quantization and arithmetic encoding. The image compressed was encrypted by Advanced Encryption Standard (AES. The images were then decoded and were compared with the original images. Experimental results showed good results in terms of Peak Signal-to-Noise Ratio (PSNR, Com-pression Ratio (CR and processing time. The proposed partial encryption schemes are fast, se-cure and do not reduce the compression performance of the underlying selected compression methods

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.

Developing a File System Structure to Solve Healthy Big Data Storage and Archiving Problems Using a Distributed File System

Directory of Open Access Journals (Sweden)

Atilla Ergüzen

2018-06-01

Full Text Available Recently, the use of internet has become widespread, increasing the use of mobile phones, tablets, computers, Internet of Things (IoT devices and other digital sources. In the health sector with the help of new generation digital medical equipment, this digital world also has tended to grow in an unpredictable way in that it has nearly 10% of the global wide data itself and continues to keep grow beyond what the other sectors have. This progress has greatly enlarged the amount of produced data which cannot be resolved with conventional methods. In this work, an efficient model for the storage of medical images using a distributed file system structure has been developed. With this work, a robust, available, scalable, and serverless solution structure has been produced, especially for storing large amounts of data in the medical field. Furthermore, the security level of the system is extreme by use of static Internet protocol (IP, user credentials, and synchronously encrypted file contents. One of the most important key features of the system is high performance and easy scalability. In this way, the system can work with fewer hardware elements and be more robust than others that use name node architecture. According to the test results, it is seen that the performance of the designed system is better than 97% from a Not Only Structured Query Language (NoSQL system, 80% from a relational database management system (RDBMS, and 74% from an operating system (OS.

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.

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.

Design of a steganographic virtual operating system

Science.gov (United States)

Ashendorf, Elan; Craver, Scott

2015-03-01

A steganographic file system is a secure file system whose very existence on a disk is concealed. Customarily, these systems hide an encrypted volume within unused disk blocks, slack space, or atop conventional encrypted volumes. These file systems are far from undetectable, however: aside from their ciphertext footprint, they require a software or driver installation whose presence can attract attention and then targeted surveillance. We describe a new steganographic operating environment that requires no visible software installation, launching instead from a concealed bootstrap program that can be extracted and invoked with a chain of common Unix commands. Our system conceals its payload within innocuous files that typically contain high-entropy data, producing a footprint that is far less conspicuous than existing methods. The system uses a local web server to provide a file system, user interface and applications through a web architecture.

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.

Optical image encryption system using nonlinear approach based on biometric authentication

Science.gov (United States)

Verma, Gaurav; Sinha, Aloka

2017-07-01

A nonlinear image encryption scheme using phase-truncated Fourier transform (PTFT) and natural logarithms is proposed in this paper. With the help of the PTFT, the input image is truncated into phase and amplitude parts at the Fourier plane. The phase-only information is kept as the secret key for the decryption, and the amplitude distribution is modulated by adding an undercover amplitude random mask in the encryption process. Furthermore, the encrypted data is kept hidden inside the face biometric-based phase mask key using the base changing rule of logarithms for secure transmission. This phase mask is generated through principal component analysis. Numerical experiments show the feasibility and the validity of the proposed nonlinear scheme. The performance of the proposed scheme has been studied against the brute force attacks and the amplitude-phase retrieval attack. Simulation results are presented to illustrate the enhanced system performance with desired advantages in comparison to the linear cryptosystem.

New Encryption Scheme of One-Time Pad Based on KDC

Science.gov (United States)

Xie, Xin; Chen, Honglei; Wu, Ying; Zhang, Heng; Wu, Peng

As more and more leakage incidents come up, traditional encryption system has not adapted to the complex and volatile network environment, so, there should be a new encryption system that can protect information security very well, this is the starting point of this paper. Based on DES and RSA encryption system, this paper proposes a new scheme of one time pad, which really achieves "One-time pad" and provides information security a new and more reliable encryption method.

An Efficient Searchable Encryption Against Keyword Guessing Attacks for Sharable Electronic Medical Records in Cloud-based System.

Science.gov (United States)

Wu, Yilun; Lu, Xicheng; Su, Jinshu; Chen, Peixin

2016-12-01

Preserving the privacy of electronic medical records (EMRs) is extremely important especially when medical systems adopt cloud services to store patients' electronic medical records. Considering both the privacy and the utilization of EMRs, some medical systems apply searchable encryption to encrypt EMRs and enable authorized users to search over these encrypted records. Since individuals would like to share their EMRs with multiple persons, how to design an efficient searchable encryption for sharable EMRs is still a very challenge work. In this paper, we propose a cost-efficient secure channel free searchable encryption (SCF-PEKS) scheme for sharable EMRs. Comparing with existing SCF-PEKS solutions, our scheme reduces the storage overhead and achieves better computation performance. Moreover, our scheme can guard against keyword guessing attack, which is neglected by most of the existing schemes. Finally, we implement both our scheme and a latest medical-based scheme to evaluate the performance. The evaluation results show that our scheme performs much better performance than the latest one for sharable EMRs.

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)

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.

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

VoIP Speech Encryption System Using Stream Cipher with Chaotic ...

African Journals Online (AJOL)

pc

2018-03-22

Mar 22, 2018 ... The technologies of Internet doesn't give any security mechanism and there is ... VoIP system, both digital (e.g., PC, PDA) and analog (e.g., telephone) devices ... the protection to speech through traditional encryption schemes ...

A Spatiotemporal-Chaos-Based Encryption Having Overall Properties Considerably Better than Advanced Encryption Standard

Science.gov (United States)

Wang, Shi-Hong; Ye, Wei-Ping; Lü, Hua-Ping; Kuang, Jin-Yu; Li, Jing-Hua; Luo, Yun-Lun; Hu, Gang

2003-07-01

Spatiotemporal chaos of a two-dimensional one-way coupled map lattice is used for chaotic cryptography. The chaotic outputs of many space units are used for encryption simultaneously. This system shows satisfactory cryptographic properties of high security, fast encryption (decryption) speed, and robustness against noise disturbances in communication channel. The overall features of this spatiotemporal-chaos-based cryptosystem are better than chaotic cryptosystems known so far, and also than currently used conventional cryptosystems, such as the Advanced Encryption Standard (AES). The project supported by National Natural Science Foundation of China under Grant No. 10175010 and the Special Funds for Major State Basic Research Projects under Grant No. G2000077304

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.

Usage of the hybrid encryption in a cloud instant messages exchange system

Science.gov (United States)

Kvyetnyy, Roman N.; Romanyuk, Olexander N.; Titarchuk, Evgenii O.; Gromaszek, Konrad; Mussabekov, Nazarbek

2016-09-01

A new approach for constructing cloud instant messaging represented in this article allows users to encrypt data locally by using Diffie - Hellman key exchange protocol. The described approach allows to construct a cloud service which operates only by users encrypted messages; encryption and decryption takes place locally at the user party using a symmetric AES encryption. A feature of the service is the conferences support without the need for messages reecryption for each participant. In the article it is given an example of the protocol implementation on the ECC and RSA encryption algorithms basis, as well as a comparison of these implementations.

Advanced technologies for encryption of satellite links

Science.gov (United States)

McMahan, Sherry S.

The use of encryption on satellite links is discussed. Advanced technology exists to provide transmission security for large earth station with data rates up to 50 megabits per second. One of the major concerns in the use of encryption equipment with very small aperture terminals (VSAT) is the key management issue and the related operational costs. The low cost requirement and the lack of physical protection of remote VSATs place severe constraints on the design of encryption equipment. Encryption may be accomplished by embedding a tamper proof encryption module into the baseband unit of each VSAT. VSAT networks are usually star networks where there is a single large earth station that serves as a hub and all satellite communications takes place between each VSAT and the hub earth station. The hub earth station has the secret master key of each VSAT. These master keys are used to downline load encrypted session keys to each VSAT. A more secure alternative is to use public key techniques where each embedded VSAT encryption module internally generates its own secret and public numbers. The secret number never leaves the module while the public number is sent to the hub at the time of initialization of the encryption module into the VSAT. Physical access control to encryption modules of VSAT systems can be implemented using passwords, smart cards or biometrics.

File Cryptography with AES and RSA for Mobile Based on Android

Science.gov (United States)

laia, Yonata; Nababan, Marlince; Sihombing, Oloan; Aisyah, Siti; Sitanggang, Delima; Parsaoran, Saut; Zendato, Niskarto

2018-04-01

The users of mobile based on android were increasing currently even now mobile was almost the same computer one of which could be used to be done by every users mobile was save the individual important data.Saving the data on mobile was very risk because become hackers’ target. That was the reason of researchers want to add cryptography which the combination between Advance Encryption System (AES) dan Ron Rivest, Adi Shamir dan Len Adleman (RSA). The result of the second method above could do cryptography data on mobile. With different encryption time where the file size; 25.44 KB, encryption time 4 second, 200 KB, 5 second, 600 KB 7 second, 2.29 MB, 10 second. Where decryption 25.44 KB, encryption 2 second, 200 KB, 1.5 second, 600 KB 2.5 second, 2.29 MB, 2.7 second.

Symmetric Encryption Relying on Chaotic Henon System for Secure Hardware-Friendly Wireless Communication of Implantable Medical Systems

Directory of Open Access Journals (Sweden)

Taha Belkhouja

2018-05-01

Full Text Available Healthcare remote devices are recognized as a promising technology for treating health related issues. Among them are the wireless Implantable Medical Devices (IMDs: These electronic devices are manufactured to treat, monitor, support or replace defected vital organs while being implanted in the human body. Thus, they play a critical role in healing and even saving lives. Current IMDs research trends concentrate on their medical reliability. However, deploying wireless technology in such applications without considering security measures may offer adversaries an easy way to compromise them. With the aim to secure these devices, we explore a new scheme that creates symmetric encryption keys to encrypt the wireless communication portion. We will rely on chaotic systems to obtain a synchronized Pseudo-Random key. The latter will be generated separately in the system in such a way that avoids a wireless key exchange, thus protecting patients from the key theft. Once the key is defined, a simple encryption system that we propose in this paper will be used. We analyze the performance of this system from a cryptographic point of view to ensure that it offers a better safety and protection for patients.

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.

Secure image encryption algorithm design using a novel chaos based S-Box

International Nuclear Information System (INIS)

Çavuşoğlu, Ünal; Kaçar, Sezgin; Pehlivan, Ihsan; Zengin, Ahmet

2017-01-01

Highlights: • A new chaotic system is developed for creating S-Box and image encryption algorithm. • Chaos based random number generator is designed with the help of the new chaotic system. NIST tests are run on generated random numbers to verify randomness. • A new S-Box design algorithm is developed to create the chaos based S-Box to be utilized in encryption algorithm and performance tests are made. • The new developed S-Box based image encryption algorithm is introduced and image encryption application is carried out. • To show the quality and strong of the encryption process, security analysis are performed and compared with the AES and chaos algorithms. - Abstract: In this study, an encryption algorithm that uses chaos based S-BOX is developed for secure and speed image encryption. First of all, a new chaotic system is developed for creating S-Box and image encryption algorithm. Chaos based random number generator is designed with the help of the new chaotic system. Then, NIST tests are run on generated random numbers to verify randomness. A new S-Box design algorithm is developed to create the chaos based S-Box to be utilized in encryption algorithm and performance tests are made. As the next step, the new developed S-Box based image encryption algorithm is introduced in detail. Finally, image encryption application is carried out. To show the quality and strong of the encryption process, security analysis are performed. Proposed algorithm is compared with the AES and chaos algorithms. According to tests results, the proposed image encryption algorithm is secure and speed for image encryption application.

Attribute-based encryption with encryption and decryption outsourcing

NARCIS (Netherlands)

Asim, M.; Petkovic, M.; Ignatenko, T.

2014-01-01

In this paper we propose a new scheme for ciphertext-policy attribute-based encryption that allows outsourcing of computationally expensive encryption and decryption steps. The scheme constitutes an important building block for mobile applications where both the host and users use mobile devices

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.

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.

Towards Symbolic Encryption Schemes

DEFF Research Database (Denmark)

Ahmed, Naveed; Jensen, Christian D.; Zenner, Erik

2012-01-01

, namely an authenticated encryption scheme that is secure under chosen ciphertext attack. Therefore, many reasonable encryption schemes, such as AES in the CBC or CFB mode, are not among the implementation options. In this paper, we report new attacks on CBC and CFB based implementations of the well......Symbolic encryption, in the style of Dolev-Yao models, is ubiquitous in formal security models. In its common use, encryption on a whole message is specified as a single monolithic block. From a cryptographic perspective, however, this may require a resource-intensive cryptographic algorithm......-known Needham-Schroeder and Denning-Sacco protocols. To avoid such problems, we advocate the use of refined notions of symbolic encryption that have natural correspondence to standard cryptographic encryption schemes....

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 with ...... modulator resolution elements, the decrypting phase value phi d (Xd, Yd) and the decrypting amplitude value ad (Xd, Yd) respectively, of a modulator resolution element (Xd, Yd) being substantially equal to - phi c (Xm, Ym) and ac (Xm, Ym)....

Error function attack of chaos synchronization based encryption schemes.

Science.gov (United States)

Wang, Xingang; Zhan, Meng; Lai, C-H; Gang, Hu

2004-03-01

Different chaos synchronization based encryption schemes are reviewed and compared from the practical point of view. As an efficient cryptanalysis tool for chaos encryption, a proposal based on the error function attack is presented systematically and used to evaluate system security. We define a quantitative measure (quality factor) of the effective applicability of a chaos encryption scheme, which takes into account the security, the encryption speed, and the robustness against channel noise. A comparison is made of several encryption schemes and it is found that a scheme based on one-way coupled chaotic map lattices performs outstandingly well, as judged from quality factor. Copyright 2004 American Institute of Physics.

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.

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.

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.

Comparison of encryption techniques between chaos theory and password for wireless power transfer system: A review

Science.gov (United States)

Hussin, N. H.; Azizan, M. M.; Ali, A.; Albreem, M. A. M.

2017-09-01

This paper reviews the techniques used in Wireless power transfer (WPT). WPT is one of the most useful ways to transfer power. Based on power transfer distances, the WPT system can be divided into three categories, namely, near, medium, and far fields. Inductive coupling and capacitive coupling contactless techniques are used in the near-field WPT. Magnetic resonant coupling technique is used in the medium-field WPT. Electromagnetic radiation is used in the far-field WPT. In addition, energy encryption plays a major role in ensuring that power is transferred to the true receiver. Therefore, this paper reviews the energy encryption techniques in WPT system. A comparison between different technique shows that the distance, efficiency, and number of receivers are the main factors in selecting the suitable energy encryption technique.

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.

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

Substring-Searchable Symmetric Encryption

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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.

Two-dimensional DFA scaling analysis applied to encrypted images

Science.gov (United States)

Vargas-Olmos, C.; Murguía, J. S.; Ramírez-Torres, M. T.; Mejía Carlos, M.; Rosu, H. C.; González-Aguilar, H.

2015-01-01

The technique of detrended fluctuation analysis (DFA) has been widely used to unveil scaling properties of many different signals. In this paper, we determine scaling properties in the encrypted images by means of a two-dimensional DFA approach. To carry out the image encryption, we use an enhanced cryptosystem based on a rule-90 cellular automaton and we compare the results obtained with its unmodified version and the encryption system AES. The numerical results show that the encrypted images present a persistent behavior which is close to that of the 1/f-noise. These results point to the possibility that the DFA scaling exponent can be used to measure the quality of the encrypted image content.

Practical and Secure Recovery of Disk Encryption Key Using Smart Cards

Science.gov (United States)

Omote, Kazumasa; Kato, Kazuhiko

In key-recovery methods using smart cards, a user can recover the disk encryption key in cooperation with the system administrator, even if the user has lost the smart card including the disk encryption key. However, the disk encryption key is known to the system administrator in advance in most key-recovery methods. Hence user's disk data may be read by the system administrator. Furthermore, if the disk encryption key is not known to the system administrator in advance, it is difficult to achieve a key authentication. In this paper, we propose a scheme which enables to recover the disk encryption key when the user's smart card is lost. In our scheme, the disk encryption key is not preserved anywhere and then the system administrator cannot know the key before key-recovery phase. Only someone who has a user's smart card and knows the user's password can decrypt that user's disk data. Furthermore, we measured the processing time required for user authentication in an experimental environment using a virtual machine monitor. As a result, we found that this processing time is short enough to be practical.

A semi-symmetric image encryption scheme based on the function projective synchronization of two hyperchaotic systems.

Directory of Open Access Journals (Sweden)

Xiaoqiang Di

Full Text Available Both symmetric and asymmetric color image encryption have advantages and disadvantages. In order to combine their advantages and try to overcome their disadvantages, chaos synchronization is used to avoid the key transmission for the proposed semi-symmetric image encryption scheme. Our scheme is a hybrid chaotic encryption algorithm, and it consists of a scrambling stage and a diffusion stage. The control law and the update rule of function projective synchronization between the 3-cell quantum cellular neural networks (QCNN response system and the 6th-order cellular neural network (CNN drive system are formulated. Since the function projective synchronization is used to synchronize the response system and drive system, Alice and Bob got the key by two different chaotic systems independently and avoid the key transmission by some extra security links, which prevents security key leakage during the transmission. Both numerical simulations and security analyses such as information entropy analysis, differential attack are conducted to verify the feasibility, security, and efficiency of the proposed scheme.

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.

FPGA BASED HARDWARE KEY FOR TEMPORAL ENCRYPTION

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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.

Chosen-plaintext attack on a joint transform correlator encrypting system

Science.gov (United States)

Barrera, John Fredy; Vargas, Carlos; Tebaldi, Myrian; Torroba, Roberto

2010-10-01

We demonstrate that optical encryption methods based on the joint transform correlator architecture are vulnerable to chosen-plaintext attack. An unauthorized user, who introduces three chosen plaintexts in the accessible encryption machine, can obtain the security key code mask. In this contribution, we also propose an alternative method to eliminate ambiguities that allows obtaining the right decrypting key.

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.

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.

Parallel Algorithm for Wireless Data Compression and Encryption

Directory of Open Access Journals (Sweden)

Qin Jiancheng

2017-01-01

Full Text Available As the wireless network has limited bandwidth and insecure shared media, the data compression and encryption are very useful for the broadcasting transportation of big data in IoT (Internet of Things. However, the traditional techniques of compression and encryption are neither competent nor efficient. In order to solve this problem, this paper presents a combined parallel algorithm named “CZ algorithm” which can compress and encrypt the big data efficiently. CZ algorithm uses a parallel pipeline, mixes the coding of compression and encryption, and supports the data window up to 1 TB (or larger. Moreover, CZ algorithm can encrypt the big data as a chaotic cryptosystem which will not decrease the compression speed. Meanwhile, a shareware named “ComZip” is developed based on CZ algorithm. The experiment results show that ComZip in 64 b system can get better compression ratio than WinRAR and 7-zip, and it can be faster than 7-zip in the big data compression. In addition, ComZip encrypts the big data without extra consumption of computing resources.

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.

SYMMETRIC ENCRYPTION USING PRE-SHARED PUBLIC PARAMETERS FOR A SECURE TFTP PROTOCOL

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N. N. MOHAMED

2017-01-01

Full Text Available Advances in the communication technology of embedded systems have led to the situation where nowadays almost all systems should implement security for data safety. Trivial File Transfer Protocol (TFTP has advantages for use in embedded systems due to its speed and simplicity, however without security mechanisms, it is vulnerable to various attacks. As an example, during upgrading of Wireless Access Points (WAPs, attackers can access the information and modify it, and then install malicious code to interrupt the system. This work proposes security implementation of Diffie Hellman Key Exchange in TFTP by pre-sharing public parameters that enable two parties to achieve same secret key without the risk of Man-In-The-Middle (MITM attacks. The implementation is integrated with compression and encryption methods to significantly reduce computational requirements in TFTP communication.

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.

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.

STFTP: Secure TFTP Protocol for Embedded Multi-Agent Systems Communication

Directory of Open Access Journals (Sweden)

ZAGAR, D.

2013-05-01

Full Text Available Today's embedded systems have evolved into multipurpose devices moving towards an embedded multi-agent system (MAS infrastructure. With the involvement of MAS in embedded systems, one remaining issues is establishing communication between agents in low computational power and low memory embedded systems without present Embedded Operating System (EOS. One solution is the extension of an outdated Trivial File Transfer Protocol (TFTP. The main advantage of using TFTP in embedded systems is the easy implementation. However, the problem at hand is the overall lack of security mechanisms in TFTP. This paper proposes an extension to the existing TFTP in a form of added security mechanisms: STFTP. The authentication is proposed using Digest Access Authentication process whereas the data encryption can be performed by various cryptographic algorithms. The proposal is experimentally tested using two embedded systems based on micro-controller architecture. Communication is analyzed for authentication, data rate and transfer time versus various data encryption ciphers and files sizes. STFTP results in an expected drop in performance, which is in the range of similar encryption algorithms. The system could be improved by using embedded systems of higher computational power or by the use of hardware encryption modules.

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.

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.

Security Analysis of a Block Encryption Algorithm Based on Dynamic Sequences of Multiple Chaotic Systems

Science.gov (United States)

Du, Mao-Kang; He, Bo; Wang, Yong

2011-01-01

Recently, the cryptosystem based on chaos has attracted much attention. Wang and Yu (Commun. Nonlin. Sci. Numer. Simulat. 14 (2009) 574) proposed a block encryption algorithm based on dynamic sequences of multiple chaotic systems. We analyze the potential flaws in the algorithm. Then, a chosen-plaintext attack is presented. Some remedial measures are suggested to avoid the flaws effectively. Furthermore, an improved encryption algorithm is proposed to resist the attacks and to keep all the merits of the original cryptosystem.

Low-power Implementation of an Encryption/Decryption System with Asynchronous Techniques

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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.

Color encryption scheme based on adapted quantum logistic map

Science.gov (United States)

Zaghloul, Alaa; Zhang, Tiejun; Amin, Mohamed; Abd El-Latif, Ahmed A.

2014-04-01

This paper presents a new color image encryption scheme based on quantum chaotic system. In this scheme, a new encryption scheme is accomplished by generating an intermediate chaotic key stream with the help of quantum chaotic logistic map. Then, each pixel is encrypted by the cipher value of the previous pixel and the adapted quantum logistic map. The results show that the proposed scheme has adequate security for the confidentiality of color images.

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

Image Steganography In Securing Sound File Using Arithmetic Coding Algorithm, Triple Data Encryption Standard (3DES) and Modified Least Significant Bit (MLSB)

Science.gov (United States)

Nasution, A. B.; Efendi, S.; Suwilo, S.

2018-04-01

The amount of data inserted in the form of audio samples that use 8 bits with LSB algorithm, affect the value of PSNR which resulted in changes in image quality of the insertion (fidelity). So in this research will be inserted audio samples using 5 bits with MLSB algorithm to reduce the number of data insertion where previously the audio sample will be compressed with Arithmetic Coding algorithm to reduce file size. In this research will also be encryption using Triple DES algorithm to better secure audio samples. The result of this research is the value of PSNR more than 50dB so it can be concluded that the image quality is still good because the value of PSNR has exceeded 40dB.

Cut-and-Paste file-systems : integrating simulators and file systems

NARCIS (Netherlands)

Bosch, H.G.P.; Mullender, Sape J.

1996-01-01

We have implemented an integrated and configurable file system called the PFS and a trace-driven file-system simulator called Patsy. Patsy is used for off-line analysis of file-system algorithms, PFS is used for on-line file-system data storage. Algorithms are first analyzed in Patsy and when we are

Video Encryption-A Survey

OpenAIRE

Jolly Shah; Vikas Saxena

2011-01-01

Multimedia data security is becoming important with the continuous increase of digital communications on internet. The encryption algorithms developed to secure text data are not suitable for multimedia application because of the large data size and real time constraint. In this paper, classification and description of various video encryption algorithms are presented. Analysis and Comparison of these algorithms with respect to various parameters like visual degradation, encryption ratio, spe...

Entropy based file type identification and partitioning

Science.gov (United States)

2017-06-01

energy spectrum,” Proceedings of the Twenty-Ninth International Florida Artificial Intelligence Research Society Conference, pp. 288–293, 2016...ABBREVIATIONS AES Advanced Encryption Standard ANN Artificial Neural Network ASCII American Standard Code for Information Interchange CWT...the identification of file types and file partitioning. This approach has applications in cybersecurity as it allows for a quick determination of

Perceptual security of encrypted images based on wavelet scaling analysis

Science.gov (United States)

Vargas-Olmos, C.; Murguía, J. S.; Ramírez-Torres, M. T.; Mejía Carlos, M.; Rosu, H. C.; González-Aguilar, H.

2016-08-01

The scaling behavior of the pixel fluctuations of encrypted images is evaluated by using the detrended fluctuation analysis based on wavelets, a modern technique that has been successfully used recently for a wide range of natural phenomena and technological processes. As encryption algorithms, we use the Advanced Encryption System (AES) in RBT mode and two versions of a cryptosystem based on cellular automata, with the encryption process applied both fully and partially by selecting different bitplanes. In all cases, the results show that the encrypted images in which no understandable information can be visually appreciated and whose pixels look totally random present a persistent scaling behavior with the scaling exponent α close to 0.5, implying no correlation between pixels when the DFA with wavelets is applied. This suggests that the scaling exponents of the encrypted images can be used as a perceptual security criterion in the sense that when their values are close to 0.5 (the white noise value) the encrypted images are more secure also from the perceptual point of view.

Breaking down the barriers of using strong authentication and encryption in resource constrained embedded systems

Science.gov (United States)

Knobler, Ron; Scheffel, Peter; Jackson, Scott; Gaj, Kris; Kaps, Jens Peter

2013-05-01

Various embedded systems, such as unattended ground sensors (UGS), are deployed in dangerous areas, where they are subject to compromise. Since numerous systems contain a network of devices that communicate with each other (often times with commercial off the shelf [COTS] radios), an adversary is able to intercept messages between system devices, which jeopardizes sensitive information transmitted by the system (e.g. location of system devices). Secret key algorithms such as AES are a very common means to encrypt all system messages to a sufficient security level, for which lightweight implementations exist for even very resource constrained devices. However, all system devices must use the appropriate key to encrypt and decrypt messages from each other. While traditional public key algorithms (PKAs), such as RSA and Elliptic Curve Cryptography (ECC), provide a sufficiently secure means to provide authentication and a means to exchange keys, these traditional PKAs are not suitable for very resource constrained embedded systems or systems which contain low reliability communication links (e.g. mesh networks), especially as the size of the network increases. Therefore, most UGS and other embedded systems resort to pre-placed keys (PPKs) or other naïve schemes which greatly reduce the security and effectiveness of the overall cryptographic approach. McQ has teamed with the Cryptographic Engineering Research Group (CERG) at George Mason University (GMU) to develop an approach using revolutionary cryptographic techniques that provides both authentication and encryption, but on resource constrained embedded devices, without the burden of large amounts of key distribution or storage.

Global chaos synchronization of three coupled nonlinear autonomous systems and a novel method of chaos encryption

International Nuclear Information System (INIS)

An Xinlei; Yu Jianning; Chu Yandong; Zhang Jiangang; Zhang Li

2009-01-01

In this paper, we discussed the fixed points and their linear stability of a new nonlinear autonomous system that introduced by J.C. Sprott. Based on Lyapunov stabilization theorem, a global chaos synchronization scheme of three coupled identical systems is investigated. By choosing proper coupling parameters, the states of all the three systems can be synchronized. Then this method was applied to secure communication through chaotic masking, used three coupled identical systems, propose a novel method of chaos encryption, after encrypting in the previous two transmitters, information signal can be recovered exactly at the receiver end. Simulation results show that the method can realize monotonous synchronization. Further more, the information signal can be recovered undistorted when applying this method to secure communication.

48 CFR 352.239-71 - Standard for encryption language.

Science.gov (United States)

2010-10-01

... language. 352.239-71 Section 352.239-71 Federal Acquisition Regulations System HEALTH AND HUMAN SERVICES... Standard for encryption language. As prescribed in 339.101(d)(2), the Contracting Officer shall insert the following clause: Standard for Encryption Language (January 2010) (a) The Contractor shall use Federal...

Cut-and-Paste file-systems: integrating simulators and file systems

NARCIS (Netherlands)

Bosch, H.G.P.; Mullender, Sape J.

1995-01-01

We have implemented an integrated and configurable file system called the Pegasus filesystem (PFS) and a trace-driven file-system simulator called Patsy. Patsy is used for off-line analysis of file-systemalgorithms, PFS is used for on-line file-systemdata storage. Algorithms are first analyzed in

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.

Digital Image Encryption Algorithm Design Based on Genetic Hyperchaos

Directory of Open Access Journals (Sweden)

Jian Wang

2016-01-01

Full Text Available In view of the present chaotic image encryption algorithm based on scrambling (diffusion is vulnerable to choosing plaintext (ciphertext attack in the process of pixel position scrambling, we put forward a image encryption algorithm based on genetic super chaotic system. The algorithm, by introducing clear feedback to the process of scrambling, makes the scrambling effect related to the initial chaos sequence and the clear text itself; it has realized the image features and the organic fusion of encryption algorithm. By introduction in the process of diffusion to encrypt plaintext feedback mechanism, it improves sensitivity of plaintext, algorithm selection plaintext, and ciphertext attack resistance. At the same time, it also makes full use of the characteristics of image information. Finally, experimental simulation and theoretical analysis show that our proposed algorithm can not only effectively resist plaintext (ciphertext attack, statistical attack, and information entropy attack but also effectively improve the efficiency of image encryption, which is a relatively secure and effective way of image communication.

Flexible CP-ABE Based Access Control on Encrypted Data for Mobile Users in Hybrid Cloud System

Institute of Scientific and Technical Information of China (English)

Wen-Min Li; Xue-Lei Li; Qiao-Yan Wen; Shuo Zhang; Hua Zhang

2017-01-01

In hybrid cloud computing, encrypted data access control can provide a fine-grained access method for orga-nizations to enact policies closer to organizational policies. This paper presents an improved CP-ABE (ciphertext-policy attribute-based encryption) scheme to construct an encrypted data access control solution that is suitable for mobile users in hybrid cloud system. In our improvement, we split the original decryption keys into a control key, a secret key and a set of transformation keys. The private cloud managed by the organization administrator takes charge of updating the transformation keys using the control key. It helps to handle the situation of flexible access management and attribute alteration. Meanwhile, the mobile user's single secret key remains unchanged as well as the ciphertext even if the data user's attribute has been revoked. In addition, we modify the access control list through adding the attributes with corresponding control key and transformation keys so as to manage user privileges depending upon the system version. Finally, the analysis shows that our scheme is secure, flexible and efficient to be applied in mobile hybrid cloud computing.

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.

Experiences on File Systems: Which is the best file system for you?

CERN Document Server

Blomer, J

2015-01-01

The distributed file system landscape is scattered. Besides a plethora of research file systems, there is also a large number of production grade file systems with various strengths and weaknesses. The file system, as an abstraction of permanent storage, is appealing because it provides application portability and integration with legacy and third-party applications, including UNIX utilities. On the other hand, the general and simple file system interface makes it notoriously difficult for a distributed file system to perform well under a variety of different workloads. This contribution provides a taxonomy of commonly used distributed file systems and points out areas of research and development that are particularly important for high-energy physics.

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.

Color image encryption based on Coupled Nonlinear Chaotic Map

International Nuclear Information System (INIS)

Mazloom, Sahar; Eftekhari-Moghadam, Amir Masud

2009-01-01

Image encryption is somehow different from text encryption due to some inherent features of image such as bulk data capacity and high correlation among pixels, which are generally difficult to handle by conventional methods. The desirable cryptographic properties of the chaotic maps such as sensitivity to initial conditions and random-like behavior have attracted the attention of cryptographers to develop new encryption algorithms. Therefore, recent researches of image encryption algorithms have been increasingly based on chaotic systems, though the drawbacks of small key space and weak security in one-dimensional chaotic cryptosystems are obvious. This paper proposes a Coupled Nonlinear Chaotic Map, called CNCM, and a novel chaos-based image encryption algorithm to encrypt color images by using CNCM. The chaotic cryptography technique which used in this paper is a symmetric key cryptography with a stream cipher structure. In order to increase the security of the proposed algorithm, 240 bit-long secret key is used to generate the initial conditions and parameters of the chaotic map by making some algebraic transformations to the key. These transformations as well as the nonlinearity and coupling structure of the CNCM have enhanced the cryptosystem security. For getting higher security and higher complexity, the current paper employs the image size and color components to cryptosystem, thereby significantly increasing the resistance to known/chosen-plaintext attacks. The results of several experimental, statistical analysis and key sensitivity tests show that the proposed image encryption scheme provides an efficient and secure way for real-time image encryption and transmission.

A novel image encryption scheme based on spatial chaos map

International Nuclear Information System (INIS)

Sun Fuyan; Liu Shutang; Li Zhongqin; Lue Zongwang

2008-01-01

In recent years, the chaos-based cryptographic algorithms have suggested some new and efficient ways to develop secure image encryption techniques, but the drawbacks of small key space and weak security in one-dimensional chaotic cryptosystems are obvious. In this paper, spatial chaos system are used for high degree security image encryption while its speed is acceptable. The proposed algorithm is described in detail. The basic idea is to encrypt the image in space with spatial chaos map pixel by pixel, and then the pixels are confused in multiple directions of space. Using this method one cycle, the image becomes indistinguishable in space due to inherent properties of spatial chaotic systems. Several experimental results, key sensitivity tests, key space analysis, and statistical analysis show that the approach for image cryptosystems provides an efficient and secure way for real time image encryption and transmission from the cryptographic viewpoint

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

Video encryption using chaotic masks in joint transform correlator

Science.gov (United States)

Saini, Nirmala; Sinha, Aloka

2015-03-01

A real-time optical video encryption technique using a chaotic map has been reported. In the proposed technique, each frame of video is encrypted using two different chaotic random phase masks in the joint transform correlator architecture. The different chaotic random phase masks can be obtained either by using different iteration levels or by using different seed values of the chaotic map. The use of different chaotic random phase masks makes the decryption process very complex for an unauthorized person. Optical, as well as digital, methods can be used for video encryption but the decryption is possible only digitally. To further enhance the security of the system, the key parameters of the chaotic map are encoded using RSA (Rivest-Shamir-Adleman) public key encryption. Numerical simulations are carried out to validate the proposed technique.

Video encryption using chaotic masks in joint transform correlator

International Nuclear Information System (INIS)

Saini, Nirmala; Sinha, Aloka

2015-01-01

A real-time optical video encryption technique using a chaotic map has been reported. In the proposed technique, each frame of video is encrypted using two different chaotic random phase masks in the joint transform correlator architecture. The different chaotic random phase masks can be obtained either by using different iteration levels or by using different seed values of the chaotic map. The use of different chaotic random phase masks makes the decryption process very complex for an unauthorized person. Optical, as well as digital, methods can be used for video encryption but the decryption is possible only digitally. To further enhance the security of the system, the key parameters of the chaotic map are encoded using RSA (Rivest–Shamir–Adleman) public key encryption. Numerical simulations are carried out to validate the proposed technique. (paper)

Image Blocking Encryption Algorithm Based on Laser Chaos Synchronization

Directory of Open Access Journals (Sweden)

Shu-Ying Wang

2016-01-01

Full Text Available In view of the digital image transmission security, based on laser chaos synchronization and Arnold cat map, a novel image encryption scheme is proposed. Based on pixel values of plain image a parameter is generated to influence the secret key. Sequences of the drive system and response system are pretreated by the same method and make image blocking encryption scheme for plain image. Finally, pixels position are scrambled by general Arnold transformation. In decryption process, the chaotic synchronization accuracy is fully considered and the relationship between the effect of synchronization and decryption is analyzed, which has characteristics of high precision, higher efficiency, simplicity, flexibility, and better controllability. The experimental results show that the encryption algorithm image has high security and good antijamming performance.

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

Accessing files in an Internet: The Jade file system

Science.gov (United States)

Peterson, Larry L.; Rao, Herman C.

1991-01-01

Jade is a new distribution file system that provides a uniform way to name and access files in an internet environment. It makes two important contributions. First, Jade is a logical system that integrates a heterogeneous collection of existing file systems, where heterogeneous means that the underlying file systems support different file access protocols. Jade is designed under the restriction that the underlying file system may not be modified. Second, rather than providing a global name space, Jade permits each user to define a private name space. These private name spaces support two novel features: they allow multiple file systems to be mounted under one directory, and they allow one logical name space to mount other logical name spaces. A prototype of the Jade File System was implemented on Sun Workstations running Unix. It consists of interfaces to the Unix file system, the Sun Network File System, the Andrew File System, and FTP. This paper motivates Jade's design, highlights several aspects of its implementation, and illustrates applications that can take advantage of its features.

Accessing files in an internet - The Jade file system

Science.gov (United States)

Rao, Herman C.; Peterson, Larry L.

1993-01-01

Jade is a new distribution file system that provides a uniform way to name and access files in an internet environment. It makes two important contributions. First, Jade is a logical system that integrates a heterogeneous collection of existing file systems, where heterogeneous means that the underlying file systems support different file access protocols. Jade is designed under the restriction that the underlying file system may not be modified. Second, rather than providing a global name space, Jade permits each user to define a private name space. These private name spaces support two novel features: they allow multiple file systems to be mounted under one directory, and they allow one logical name space to mount other logical name spaces. A prototype of the Jade File System was implemented on Sun Workstations running Unix. It consists of interfaces to the Unix file system, the Sun Network File System, the Andrew File System, and FTP. This paper motivates Jade's design, highlights several aspects of its implementation, and illustrates applications that can take advantage of its features.

Large-scale electrophysiology: acquisition, compression, encryption, and storage of big data.

Science.gov (United States)

Brinkmann, Benjamin H; Bower, Mark R; Stengel, Keith A; Worrell, Gregory A; Stead, Matt

2009-05-30

The use of large-scale electrophysiology to obtain high spatiotemporal resolution brain recordings (>100 channels) capable of probing the range of neural activity from local field potential oscillations to single-neuron action potentials presents new challenges for data acquisition, storage, and analysis. Our group is currently performing continuous, long-term electrophysiological recordings in human subjects undergoing evaluation for epilepsy surgery using hybrid intracranial electrodes composed of up to 320 micro- and clinical macroelectrode arrays. DC-capable amplifiers, sampling at 32kHz per channel with 18-bits of A/D resolution are capable of resolving extracellular voltages spanning single-neuron action potentials, high frequency oscillations, and high amplitude ultra-slow activity, but this approach generates 3 terabytes of data per day (at 4 bytes per sample) using current data formats. Data compression can provide several practical benefits, but only if data can be compressed and appended to files in real-time in a format that allows random access to data segments of varying size. Here we describe a state-of-the-art, scalable, electrophysiology platform designed for acquisition, compression, encryption, and storage of large-scale data. Data are stored in a file format that incorporates lossless data compression using range-encoded differences, a 32-bit cyclically redundant checksum to ensure data integrity, and 128-bit encryption for protection of patient information.

Stream Deniable-Encryption Algorithms

Directory of Open Access Journals (Sweden)

N.A. Moldovyan

2016-04-01

Full Text Available A method for stream deniable encryption of secret message is proposed, which is computationally indistinguishable from the probabilistic encryption of some fake message. The method uses generation of two key streams with some secure block cipher. One of the key streams is generated depending on the secret key and the other one is generated depending on the fake key. The key streams are mixed with the secret and fake data streams so that the output ciphertext looks like the ciphertext produced by some probabilistic encryption algorithm applied to the fake message, while using the fake key. When the receiver or/and sender of the ciphertext are coerced to open the encryption key and the source message, they open the fake key and the fake message. To disclose their lie the coercer should demonstrate possibility of the alternative decryption of the ciphertext, however this is a computationally hard problem.

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.

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.

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.

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

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.

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.

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

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.

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.

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

Message Encryption in Robot Operating System: Collateral Effects of Hardening Mobile Robots

Directory of Open Access Journals (Sweden)

Francisco J. Rodríguez-Lera

2018-03-01

Full Text Available In human–robot interaction situations, robot sensors collect huge amounts of data from the environment in order to characterize the situation. Some of the gathered data ought to be treated as private, such as medical data (i.e., medication guidelines, personal, and safety information (i.e., images of children, home habits, alarm codes, etc.. However, most robotic software development frameworks are not designed for securely managing this information. This paper analyzes the scenario of hardening one of the most widely used robotic middlewares, Robot Operating System (ROS. The study investigates a robot’s performance when ciphering the messages interchanged between ROS nodes under the publish/subscribe paradigm. In particular, this research focuses on the nodes that manage cameras and LIDAR sensors, which are two of the most extended sensing solutions in mobile robotics, and analyzes the collateral effects on the robot’s achievement under different computing capabilities and encryption algorithms (3DES, AES, and Blowfish to robot performance. The findings present empirical evidence that simple encryption algorithms are lightweight enough to provide cyber-security even in low-powered robots when carefully designed and implemented. Nevertheless, these techniques come with a number of serious drawbacks regarding robot autonomy and performance if they are applied randomly. To avoid these issues, we define a taxonomy that links the type of ROS message, computational units, and the encryption methods. As a result, we present a model to select the optimal options for hardening a mobile robot using ROS.

Multiscale electrophysiology format: an open-source electrophysiology format using data compression, encryption, and cyclic redundancy check.

Science.gov (United States)

Brinkmann, Benjamin H; Bower, Mark R; Stengel, Keith A; Worrell, Gregory A; Stead, Matt

2009-01-01

Continuous, long-term (up to 10 days) electrophysiological monitoring using hybrid intracranial electrodes is an emerging tool for presurgical epilepsy evaluation and fundamental investigations of seizure generation. Detection of high-frequency oscillations and microseizures could provide valuable insights into causes and therapies for the treatment of epilepsy, but requires high spatial and temporal resolution. Our group is currently using hybrid arrays composed of up to 320 micro- and clinical macroelectrode arrays sampled at 32 kHz per channel with 18-bits of A/D resolution. Such recordings produce approximately 3 terabytes of data per day. Existing file formats have limited data compression capabilities, and do not offer mechanisms for protecting patient identifying information or detecting data corruption during transmission or storage. We present a novel file format that employs range encoding to provide a high degree of data compression, a three-tiered 128-bit encryption system for patient information and data security, and a 32-bit cyclic redundancy check to verify the integrity of compressed data blocks. Open-source software to read, write, and process these files are provided.

78 FR 73509 - Privacy Act of 1974; System of Records

Science.gov (United States)

2013-12-06

... files and Manpower Authorization files, including name; grade/rank; Social Security Number (SSN); DoD ID Number, gender; Military Occupational Skills and/or Civilian Occupational Series; additional Skill.... The system employs secure socket layer certificate and the Social Security Number data is encrypted to...

Shorter Decentralized Attribute-Based Encryption via Extended Dual System Groups

Directory of Open Access Journals (Sweden)

Jie Zhang

2017-01-01

Full Text Available Decentralized attribute-based encryption (ABE is a special form of multiauthority ABE systems, in which no central authority and global coordination are required other than creating the common reference parameters. In this paper, we propose a new decentralized ABE in prime-order groups by using extended dual system groups. We formulate some assumptions used to prove the security of our scheme. Our proposed scheme is fully secure under the standard k-Lin assumption in random oracle model and can support any monotone access structures. Compared with existing fully secure decentralized ABE systems, our construction has shorter ciphertexts and secret keys. Moreover, fast decryption is achieved in our system, in which ciphertexts can be decrypted with a constant number of pairings.

Distributed Searchable Symmetric Encryption

NARCIS (Netherlands)

Bösch, C.T.; Peter, Andreas; Leenders, Bram; Lim, Hoon Wei; Tang, Qiang; Wang, Huaxiong; Hartel, Pieter H.; Jonker, Willem

Searchable Symmetric Encryption (SSE) allows a client to store encrypted data on a storage provider in such a way, that the client is able to search and retrieve the data selectively without the storage provider learning the contents of the data or the words being searched for. Practical SSE schemes

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 (ABRKS), 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, ABRKS 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 ABRKS, and propose two concrete constructions for ABRKS: key-policy ABRKS and ciphertext-policy ABRKS. 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.

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

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.

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

An encryption scheme for a secure policy updating

NARCIS (Netherlands)

Ibraimi, L.; Asim, M.; Petkovic, M.; Obaidat, M.S.; Tsihrintzis, G.A.; Filipe, J.

2012-01-01

Ciphertext policy attribute based encryption is an encryption technique where the data is encrypted according to an access policy over attributes. Users who have a secret key associated with a set of attributes which satisfy the access policy can decrypt the encrypted data. However, one of the

76 FR 66666 - Basic Service Tier Encryption Compatibility Between Cable Systems and Consumer Electronics Equipment

Science.gov (United States)

2011-10-27

... 11-153] Basic Service Tier Encryption Compatibility Between Cable Systems and Consumer Electronics... substantially affect compatibility between cable service and consumer electronics equipment for most subscribers... problems between cable service and consumer electronics equipment were limiting and/or precluding the...

Encryption and validation of multiple signals for optical identification systems

International Nuclear Information System (INIS)

Perez-Cabre, E; Millan, M S; Javidi, B

2007-01-01

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

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.

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.

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.

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

Science.gov (United States)

2016-04-01

were built in-house at the SUNY Poly-technic Institute’s Center for Semiconductor Research ( CSR ); however, the initial devices for materials screening...A code that models the sweep-mode behavior of the bipolar ReRAM device that is initially in HRS. ............................................ 15...Standard (AES). AES is one of the most important encryption systems and is widely used in military and commercial systems. Based on an iterative

CHAOS-BASED ADVANCED ENCRYPTION STANDARD

KAUST Repository

Abdulwahed, Naif B.

2013-01-01

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

A Survey of Provably Secure Searchable Encryption

NARCIS (Netherlands)

Bösch, C.T.; Hartel, Pieter H.; Jonker, Willem; Peter, Andreas

We survey the notion of provably secure Searchable Encryption (SE) by giving a complete and comprehensive overview of the two main SE techniques: Searchable Symmetric Encryption (SSE) and Public Key Encryption with Keyword Search (PEKS). Since the pioneering work of Song, Wagner and Perrig (IEEE S&P

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.

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.

PDF file encryption on mobile phone using super-encryption of Variably Modified Permutation Composition (VMPC) and two square cipher algorithm

Science.gov (United States)

Rachmawati, D.; Budiman, M. A.; Atika, F.

2018-03-01

Data security is becoming one of the most significant challenges in the digital world. Retrieval of data by unauthorized parties will result in harm to the owner of the data. PDF data are also susceptible to data security disorder. These things affect the security of the information. To solve the security problem, it needs a method to maintain the protection of the data, such as cryptography. In cryptography, several algorithms can encode data, one of them is Two Square Cipher algorithm which is a symmetric algorithm. At this research, Two Square Cipher algorithm has already developed into a 16 x 16 key aims to enter the various plaintexts. However, for more enhancement security it will be combined with the VMPC algorithm which is a symmetric algorithm. The combination of the two algorithms is called with the super-encryption. At this point, the data already can be stored on a mobile phone allowing users to secure data flexibly and can be accessed anywhere. The application of PDF document security on this research built by Android-platform. At this study will also calculate the complexity of algorithms and process time. Based on the test results the complexity of the algorithm is θ (n) for Two Square Cipher and θ (n) for VMPC algorithm, so the complexity of the super-encryption is also θ (n). VMPC algorithm processing time results quicker than on Two Square Cipher. And the processing time is directly proportional to the length of the plaintext and passwords.

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.

Hardware Realization of Chaos Based Symmetric Image Encryption

KAUST Repository

Barakat, Mohamed L.

2012-01-01

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

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.

A Metadata-Rich File System

Energy Technology Data Exchange (ETDEWEB)

Ames, S; Gokhale, M B; Maltzahn, C

2009-01-07

Despite continual improvements in the performance and reliability of large scale file systems, the management of file system metadata has changed little in the past decade. The mismatch between the size and complexity of large scale data stores and their ability to organize and query their metadata has led to a de facto standard in which raw data is stored in traditional file systems, while related, application-specific metadata is stored in relational databases. This separation of data and metadata requires considerable effort to maintain consistency and can result in complex, slow, and inflexible system operation. To address these problems, we have developed the Quasar File System (QFS), a metadata-rich file system in which files, metadata, and file relationships are all first class objects. In contrast to hierarchical file systems and relational databases, QFS defines a graph data model composed of files and their relationships. QFS includes Quasar, an XPATH-extended query language for searching the file system. Results from our QFS prototype show the effectiveness of this approach. Compared to the defacto standard, the QFS prototype shows superior ingest performance and comparable query performance on user metadata-intensive operations and superior performance on normal file metadata operations.

An image encryption scheme based on the MLNCML system using DNA sequences

Science.gov (United States)

Zhang, Ying-Qian; Wang, Xing-Yuan; Liu, Jia; Chi, Ze-Lin

2016-07-01

We propose a new image scheme based on the spatiotemporal chaos of the Mixed Linear-Nonlinear Coupled Map Lattices (MLNCML). This spatiotemporal chaotic system has more cryptographic features in dynamics than the system of Coupled Map Lattices (CML). In the proposed scheme, we employ the strategy of DNA computing and one time pad encryption policy, which can enhance the sensitivity to the plaintext and resist differential attack, brute-force attack, statistical attack and plaintext attack. Simulation results and theoretical analysis indicate that the proposed scheme has superior high security.

System of end-to-end symmetric database encryption

Science.gov (United States)

Galushka, V. V.; Aydinyan, A. R.; Tsvetkova, O. L.; Fathi, V. A.; Fathi, D. V.

2018-05-01

The article is devoted to the actual problem of protecting databases from information leakage, which is performed while bypassing access control mechanisms. To solve this problem, it is proposed to use end-to-end data encryption, implemented at the end nodes of an interaction of the information system components using one of the symmetric cryptographic algorithms. For this purpose, a key management method designed for use in a multi-user system based on the distributed key representation model, part of which is stored in the database, and the other part is obtained by converting the user's password, has been developed and described. In this case, the key is calculated immediately before the cryptographic transformations and is not stored in the memory after the completion of these transformations. Algorithms for registering and authorizing a user, as well as changing his password, have been described, and the methods for calculating parts of a key when performing these operations have been provided.

Secure Cloud Computing Using Homomorphic Encryption

Directory of Open Access Journals (Sweden)

Alexander Olegovich Zhirov

2013-02-01

Full Text Available The question of cloud security has become more significant with growing popularity of cloud computing. This article is dedicated to fully homomorphic encryption which is one of the most promising methods to reach the necessary level of privacy. In this article we consider the basic ideas on homomorphic encryption proposed by C. Gentry, make generalization of them and propose three new fully homomorphic encryption schemes based on polynomial rings.

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.

Continuous QKD and high speed data encryption

Science.gov (United States)

Zbinden, Hugo; Walenta, Nino; Guinnard, Olivier; Houlmann, Raphael; Wen, Charles Lim Ci; Korzh, Boris; Lunghi, Tommaso; Gisin, Nicolas; Burg, Andreas; Constantin, Jeremy; Legré, Matthieu; Trinkler, Patrick; Caselunghe, Dario; Kulesza, Natalia; Trolliet, Gregory; Vannel, Fabien; Junod, Pascal; Auberson, Olivier; Graf, Yoan; Curchod, Gilles; Habegger, Gilles; Messerli, Etienne; Portmann, Christopher; Henzen, Luca; Keller, Christoph; Pendl, Christian; Mühlberghuber, Michael; Roth, Christoph; Felber, Norbert; Gürkaynak, Frank; Schöni, Daniel; Muheim, Beat

2013-10-01

We present the results of a Swiss project dedicated to the development of high speed quantum key distribution and data encryption. The QKD engine features fully automated key exchange, hardware key distillation based on finite key security analysis, efficient authentication and wavelength division multiplexing of the quantum and the classical channel and one-time pas encryption. The encryption device allows authenticated symmetric key encryption (e.g AES) at rates of up to 100 Gb/s. A new quantum key can uploaded up to 1000 times second from the QKD engine.

Can homomorphic encryption be practical?

NARCIS (Netherlands)

Lauter, K.; Naehrig, M.; Vaikuntanathan, V.

2011-01-01

The prospect of outsourcing an increasing amount of data storage and management to cloud services raises many new privacy concerns for individuals and businesses alike. The privacy concerns can be satisfactorily addressed if users encrypt the data they send to the cloud. If the encryption scheme is

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 ...

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.

A File Archival System

Science.gov (United States)

Fanselow, J. L.; Vavrus, J. L.

1984-01-01

ARCH, file archival system for DEC VAX, provides for easy offline storage and retrieval of arbitrary files on DEC VAX system. System designed to eliminate situations that tie up disk space and lead to confusion when different programers develop different versions of same programs and associated files.

Homomorphic encryption and secure comparison

NARCIS (Netherlands)

Damgard, Ivan; Geisler, M.; Kroigaard, M.

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

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...

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.

Image encryption using fingerprint as key based on phase retrieval algorithm and public key cryptography

Science.gov (United States)

Zhao, Tieyu; Ran, Qiwen; Yuan, Lin; Chi, Yingying; Ma, Jing

2015-09-01

In this paper, a novel image encryption system with fingerprint used as a secret key is proposed based on the phase retrieval algorithm and RSA public key algorithm. In the system, the encryption keys include the fingerprint and the public key of RSA algorithm, while the decryption keys are the fingerprint and the private key of RSA algorithm. If the users share the fingerprint, then the system will meet the basic agreement of asymmetric cryptography. The system is also applicable for the information authentication. The fingerprint as secret key is used in both the encryption and decryption processes so that the receiver can identify the authenticity of the ciphertext by using the fingerprint in decryption process. Finally, the simulation results show the validity of the encryption scheme and the high robustness against attacks based on the phase retrieval technique.

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.

A pipelined FPGA implementation of an encryption algorithm based on genetic algorithm

Science.gov (United States)

Thirer, Nonel

2013-05-01

With the evolution of digital data storage and exchange, it is essential to protect the confidential information from every unauthorized access. High performance encryption algorithms were developed and implemented by software and hardware. Also many methods to attack the cipher text were developed. In the last years, the genetic algorithm has gained much interest in cryptanalysis of cipher texts and also in encryption ciphers. This paper analyses the possibility to use the genetic algorithm as a multiple key sequence generator for an AES (Advanced Encryption Standard) cryptographic system, and also to use a three stages pipeline (with four main blocks: Input data, AES Core, Key generator, Output data) to provide a fast encryption and storage/transmission of a large amount of data.

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.

Secret Sharing Schemes and Advanced Encryption Standard

Science.gov (United States)

2015-09-01

25 4.7 Computational Example . . . . . . . . . . . . . . . . . . . . . 26 5 Side-Channel Effect on Advanced Encryption Standard ( AES ) 31...improvements, and to build upon them to discuss the side-channel effects on the Advanced Encryption Standard ( AES ). The following questions are asked...secret sharing scheme? • Can the improvements to the current secret sharing scheme prove to be beneficial in strengthening/weakening AES encryption

A fast chaotic encryption scheme based on piecewise nonlinear chaotic maps

International Nuclear Information System (INIS)

Behnia, S.; Akhshani, A.; Ahadpour, S.; Mahmodi, H.; Akhavan, A.

2007-01-01

In recent years, a growing number of discrete chaotic cryptographic algorithms have been proposed. However, most of them encounter some problems such as the lack of robustness and security. In this Letter, we introduce a new image encryption algorithm based on one-dimensional piecewise nonlinear chaotic maps. The system is a measurable dynamical system with an interesting property of being either ergodic or having stable period-one fixed point. They bifurcate from a stable single periodic state to chaotic one and vice versa without having usual period-doubling or period-n-tippling scenario. Also, we present the KS-entropy of this maps with respect to control parameter. This algorithm tries to improve the problem of failure of encryption such as small key space, encryption speed and level of security

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

Directory of Open Access Journals (Sweden)

Changji Wang

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

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.

Parallel data encryption with RSA algorithm

OpenAIRE

Неретин, А. А.

2016-01-01

In this paper a parallel RSA algorithm with preliminary shuffling of source text was presented.Dependence of an encryption speed on the number of encryption nodes has been analysed, The proposed algorithm was implemented on C# language.

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.

System using data compression and hashing adapted for use for multimedia encryption

Science.gov (United States)

Coffland, Douglas R [Livermore, CA

2011-07-12

A system and method is disclosed for multimedia encryption. Within the system of the present invention, a data compression module receives and compresses a media signal into a compressed data stream. A data acquisition module receives and selects a set of data from the compressed data stream. And, a hashing module receives and hashes the set of data into a keyword. The method of the present invention includes the steps of compressing a media signal into a compressed data stream; selecting a set of data from the compressed data stream; and hashing the set of data into a keyword.

An Image Encryption Algorithm Based on Balanced Pixel and Chaotic Map

Directory of Open Access Journals (Sweden)

Jian Zhang

2014-01-01

Full Text Available Image encryption technology has been applied in many fields and is becoming the main way of protecting the image information security. There are also many ways of image encryption. However, the existing encryption algorithms, in order to obtain a better effect of encryption, always need encrypting several times. There is not an effective method to decide the number of encryption times, generally determined by the human eyes. The paper proposes an image encryption algorithm based on chaos and simultaneously proposes a balanced pixel algorithm to determine the times of image encryption. Many simulation experiments have been done including encryption effect and security analysis. Experimental results show that the proposed method is feasible and effective.

Computing on Encrypted Data: Theory and Application

Science.gov (United States)

2016-01-01

permits short ciphertexts – e.g., encrypted using AES – to be de-compressed to longer ciphertexts that permit homomorphic operations. Bootstrapping...allows us to save memory by storing data encrypted in the compressed form – e.g., under AES . Here, we revisit bootstrapping, viewing it as an...COMPUTING ON ENCRYPTED DATA: THEORY AND APPLICATION MASSACHUSETTS INSTITUTE OF TECHNOLOGY JANUARY 2016 FINAL TECHNICAL REPORT

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).

Building a parallel file system simulator

International Nuclear Information System (INIS)

Molina-Estolano, E; Maltzahn, C; Brandt, S A; Bent, J

2009-01-01

Parallel file systems are gaining in popularity in high-end computing centers as well as commercial data centers. High-end computing systems are expected to scale exponentially and to pose new challenges to their storage scalability in terms of cost and power. To address these challenges scientists and file system designers will need a thorough understanding of the design space of parallel file systems. Yet there exist few systematic studies of parallel file system behavior at petabyte- and exabyte scale. An important reason is the significant cost of getting access to large-scale hardware to test parallel file systems. To contribute to this understanding we are building a parallel file system simulator that can simulate parallel file systems at very large scale. Our goal is to simulate petabyte-scale parallel file systems on a small cluster or even a single machine in reasonable time and fidelity. With this simulator, file system experts will be able to tune existing file systems for specific workloads, scientists and file system deployment engineers will be able to better communicate workload requirements, file system designers and researchers will be able to try out design alternatives and innovations at scale, and instructors will be able to study very large-scale parallel file system behavior in the class room. In this paper we describe our approach and provide preliminary results that are encouraging both in terms of fidelity and simulation scalability.

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, e...

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.

Towards an Information Theoretic Analysis of Searchable Encryption

NARCIS (Netherlands)

Sedghi, S.; Doumen, J.M.; Hartel, Pieter H.; Jonker, Willem

2008-01-01

Searchable encryption is a technique that allows a client to store data in encrypted form on a curious server, such that data can be retrieved while leaking a minimal amount of information to the server. Many searchable encryption schemes have been proposed and proved secure in their own

75 FR 36481 - Encryption Export Controls: Revision of License Exception ENC and Mass Market Eligibility...

Science.gov (United States)

2010-06-25

.... Upon effectiveness of this rule, BIS will send encryption SNAP-R submissions to the ENC Encryption... fire alarm, HVAC); automotive, aviation, and other transportation systems; LCD TV, Blu-ray/DVD, video...

Zebra: A striped network file system

Science.gov (United States)

Hartman, John H.; Ousterhout, John K.

1992-01-01

The design of Zebra, a striped network file system, is presented. Zebra applies ideas from log-structured file system (LFS) and RAID research to network file systems, resulting in a network file system that has scalable performance, uses its servers efficiently even when its applications are using small files, and provides high availability. Zebra stripes file data across multiple servers, so that the file transfer rate is not limited by the performance of a single server. High availability is achieved by maintaining parity information for the file system. If a server fails its contents can be reconstructed using the contents of the remaining servers and the parity information. Zebra differs from existing striped file systems in the way it stripes file data: Zebra does not stripe on a per-file basis; instead it stripes the stream of bytes written by each client. Clients write to the servers in units called stripe fragments, which are analogous to segments in an LFS. Stripe fragments contain file blocks that were written recently, without regard to which file they belong. This method of striping has numerous advantages over per-file striping, including increased server efficiency, efficient parity computation, and elimination of parity update.

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

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.

Quantum Encryption Minimising Key Leakage under Known Plaintext Attacks

DEFF Research Database (Denmark)

Pedersen, Thomas Brochmann

2006-01-01

, 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....... In this encryption scheme the entire key can be safely recycled when no eavesdropping is detected....

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.

A novel algorithm for thermal image encryption.

Science.gov (United States)

Hussain, Iqtadar; Anees, Amir; Algarni, Abdulmohsen

2018-04-16

Thermal images play a vital character at nuclear plants, Power stations, Forensic labs biological research, and petroleum products extraction. Safety of thermal images is very important. Image data has some unique features such as intensity, contrast, homogeneity, entropy and correlation among pixels that is why somehow image encryption is trickier as compare to other encryptions. With conventional image encryption schemes it is normally hard to handle these features. Therefore, cryptographers have paid attention to some attractive properties of the chaotic maps such as randomness and sensitivity to build up novel cryptosystems. That is why, recently proposed image encryption techniques progressively more depends on the application of chaotic maps. This paper proposed an image encryption algorithm based on Chebyshev chaotic map and S8 Symmetric group of permutation based substitution boxes. Primarily, parameters of chaotic Chebyshev map are chosen as a secret key to mystify the primary image. Then, the plaintext image is encrypted by the method generated from the substitution boxes and Chebyshev map. By this process, we can get a cipher text image that is perfectly twisted and dispersed. The outcomes of renowned experiments, key sensitivity tests and statistical analysis confirm that the proposed algorithm offers a safe and efficient approach for real-time image encryption.

A symmetrical image encryption scheme in wavelet and time domain

Science.gov (United States)

Luo, Yuling; Du, Minghui; Liu, Junxiu

2015-02-01

There has been an increasing concern for effective storages and secure transactions of multimedia information over the Internet. Then a great variety of encryption schemes have been proposed to ensure the information security while transmitting, but most of current approaches are designed to diffuse the data only in spatial domain which result in reducing storage efficiency. A lightweight image encryption strategy based on chaos is proposed in this paper. The encryption process is designed in transform domain. The original image is decomposed into approximation and detail components using integer wavelet transform (IWT); then as the more important component of the image, the approximation coefficients are diffused by secret keys generated from a spatiotemporal chaotic system followed by inverse IWT to construct the diffused image; finally a plain permutation is performed for diffusion image by the Logistic mapping in order to reduce the correlation between adjacent pixels further. Experimental results and performance analysis demonstrate the proposed scheme is an efficient, secure and robust encryption mechanism and it realizes effective coding compression to satisfy desirable storage.

A Novel Recommendation To AES Limitation

Directory of Open Access Journals (Sweden)

Falguni Patel

2017-07-01

Full Text Available Among all available conventional encryption algorithms the AES Advanced Encryption Standard is the most secured and highly used algorithm. AES algorithm is widely used by variety of applications like Archive and Compression tools File Encryption Encryption File System Disk Partition Encryption Networking Signal Protocol among others. This paper highlights the Brute Force attack and Cryptanalysis attack on AES Algorithm. This paper also discusses about a novel recommendation of a combination model of AES Algorithm and Random-X Cipher.

Transparent Data Encryption -- Solution for Security of Database Contents

OpenAIRE

Deshmukh, Dr. Anwar Pasha; Qureshi, Dr. Riyazuddin

2013-01-01

The present study deals with Transparent Data Encryption which is a technology used to solve the problems of security of data. Transparent Data Encryption means encrypting databases on hard disk and on any backup media. Present day global business environment presents numerous security threats and compliance challenges. To protect against data thefts and frauds we require security solutions that are transparent by design. Transparent Data Encryption provides transparent, standards-based secur...

VLSI implementation of RSA encryption system using ancient Indian Vedic mathematics

Science.gov (United States)

Thapliyal, Himanshu; Srinivas, M. B.

2005-06-01

This paper proposes the hardware implementation of RSA encryption/decryption algorithm using the algorithms of Ancient Indian Vedic Mathematics that have been modified to improve performance. The recently proposed hierarchical overlay multiplier architecture is used in the RSA circuitry for multiplication operation. The most significant aspect of the paper is the development of a division architecture based on Straight Division algorithm of Ancient Indian Vedic Mathematics and embedding it in RSA encryption/decryption circuitry for improved efficiency. The coding is done in Verilog HDL and the FPGA synthesis is done using Xilinx Spartan library. The results show that RSA circuitry implemented using Vedic division and multiplication is efficient in terms of area/speed compared to its implementation using conventional multiplication and division architectures.

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.

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.

An Image Encryption Scheme Based on Hyperchaotic Rabinovich and Exponential Chaos Maps

Directory of Open Access Journals (Sweden)

Xiaojun Tong

2015-01-01

Full Text Available This paper proposes a new four-dimensional hyperchaotic map based on the Rabinovich system to realize chaotic encryption in higher dimension and improve the security. The chaotic sequences generated by Runge-Kutta method are combined with the chaotic sequences generated by an exponential chaos map to generate key sequences. The key sequences are used for image encryption. The security test results indicate that the new hyperchaotic system has high security and complexity. The comparison between the new hyperchaotic system and the several low-dimensional chaotic systems shows that the proposed system performs more efficiently.

OCML-based colour image encryption

International Nuclear Information System (INIS)

Rhouma, Rhouma; Meherzi, Soumaya; Belghith, Safya

2009-01-01

The chaos-based cryptographic algorithms have suggested some new ways to develop efficient image-encryption schemes. While most of these schemes are based on low-dimensional chaotic maps, it has been proposed recently to use high-dimensional chaos namely spatiotemporal chaos, which is modelled by one-way coupled-map lattices (OCML). Owing to their hyperchaotic behaviour, such systems are assumed to enhance the cryptosystem security. In this paper, we propose an OCML-based colour image encryption scheme with a stream cipher structure. We use a 192-bit-long external key to generate the initial conditions and the parameters of the OCML. We have made several tests to check the security of the proposed cryptosystem namely, statistical tests including histogram analysis, calculus of the correlation coefficients of adjacent pixels, security test against differential attack including calculus of the number of pixel change rate (NPCR) and unified average changing intensity (UACI), and entropy calculus. The cryptosystem speed is analyzed and tested as well.

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)

Revisiting the Practicality of Search on Encrypted Data: From the Security Broker’s Perspective

Directory of Open Access Journals (Sweden)

Peiyi Han

2016-01-01

Full Text Available The primary business challenge for the customers to use outsourced computation and storage is the loss of data control and security. So encryption will become a commodity in the near future. There is big diffusion with the above scenario: take advantage of current application’s full functionalities at the same time ensuring their sensitive data remains protected and under customers’ control. Prior works have achieved effective progress towards satisfying both sides. But there are still some technical challenges, such as supporting file or data-stream based applications and supporting full-text and advanced searches. In this paper, a novel security broker based encrypted data search scheme, called Enc-YUN, is proposed, which transparently builds a reverse index at the security broker when the data flow is transmitted to the cloud. And search firstly takes place on the index, in which the mapping structure corresponds to and retrieves the very encrypted data in the cloud on behalf of the client. With this scheme, updated-to-date full-text search techniques can be easily integrated to carry out the most advanced search functionalities, at the same time, maintaining the strongest levels of data protection from curious providers or third parties. Experimental results show that Enc-YUN is effective with broad categories of cloud applications, and the performance overhead induced is minor and acceptable according to user’s perceptual experience.

An Image Encryption Approach Using a Shuffling Map

International Nuclear Information System (INIS)

Xiao Yongliang; Xia Limin

2009-01-01

A new image encryption approach is proposed. First, a sort transformation based on nonlinear chaotic algorithm is used to shuffle the positions of image pixels. Then the states of hyper-chaos are used to change the grey values of the shuffled image according to the changed chaotic values of the same position between the above nonlinear chaotic sequence and the sorted chaotic sequence. The experimental results demonstrate that the image encryption scheme based on a shuffling map shows advantages of large key space and high-level security. Compared with some encryption algorithms, the suggested encryption scheme is more secure. (general)

Hardware Realization of Chaos-based Symmetric Video Encryption

KAUST Repository

Ibrahim, Mohamad A.

2013-01-01

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

Tape SCSI monitoring and encryption at CERN

Science.gov (United States)

Laskaridis, Stefanos; Bahyl, V.; Cano, E.; Leduc, J.; Murray, S.; Cancio, G.; Kruse, D.

2017-10-01

CERN currently manages the largest data archive in the HEP domain; over 180PB of custodial data is archived across 7 enterprise tape libraries containing more than 25,000 tapes and using over 100 tape drives. Archival storage at this scale requires a leading edge monitoring infrastructure that acquires live and lifelong metrics from the hardware in order to assess and proactively identify potential drive and media level issues. In addition, protecting the privacy of sensitive archival data is becoming increasingly important and with it the need for a scalable, compute-efficient and cost-effective solution for data encryption. In this paper, we first describe the implementation of acquiring tape medium and drive related metrics reported by the SCSI interface and its integration with our monitoring system. We then address the incorporation of tape drive real-time encryption with dedicated drive hardware into the CASTOR [1] hierarchical mass storage system.

Optical encryption of multiple three-dimensional objects based on multiple interferences and single-pixel digital holography

Science.gov (United States)

Wang, Ying; Liu, Qi; Wang, Jun; Wang, Qiong-Hua

2018-03-01

We present an optical encryption method of multiple three-dimensional objects based on multiple interferences and single-pixel digital holography. By modifying the Mach–Zehnder interferometer, the interference of the multiple objects beams and the one reference beam is used to simultaneously encrypt multiple objects into a ciphertext. During decryption, each three-dimensional object can be decrypted independently without having to decrypt other objects. Since the single-pixel digital holography based on compressive sensing theory is introduced, the encrypted data of this method is effectively reduced. In addition, recording fewer encrypted data can greatly reduce the bandwidth of network transmission. Moreover, the compressive sensing essentially serves as a secret key that makes an intruder attack invalid, which means that the system is more secure than the conventional encryption method. Simulation results demonstrate the feasibility of the proposed method and show that the system has good security performance. Project supported by the National Natural Science Foundation of China (Grant Nos. 61405130 and 61320106015).

Modified Projective Synchronization between Different Fractional-Order Systems Based on Open-Plus-Closed-Loop Control and Its Application in Image Encryption

Directory of Open Access Journals (Sweden)

Hongjuan Liu

2014-01-01

Full Text Available A new general and systematic coupling scheme is developed to achieve the modified projective synchronization (MPS of different fractional-order systems under parameter mismatch via the Open-Plus-Closed-Loop (OPCL control. Based on the stability theorem of linear fractional-order systems, some sufficient conditions for MPS are proposed. Two groups of numerical simulations on the incommensurate fraction-order system and commensurate fraction-order system are presented to justify the theoretical analysis. Due to the unpredictability of the scale factors and the use of fractional-order systems, the chaotic data from the MPS is selected to encrypt a plain image to obtain higher security. Simulation results show that our method is efficient with a large key space, high sensitivity to encryption keys, resistance to attack of differential attacks, and statistical analysis.

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%.

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

Formalizing a hierarchical file system

NARCIS (Netherlands)

Hesselink, Wim H.; Lali, Muhammad Ikram

An abstract file system is defined here as a partial function from (absolute) paths to data. Such a file system determines the set of valid paths. It allows the file system to be read and written at a valid path, and it allows the system to be modified by the Unix operations for creation, removal,

Rancang Bangun Aplikasi Enkripsi dan Dekripsi Email Dengan Menggunakan Algoritma Advanced Encryption Standard Dan Knapsack

Directory of Open Access Journals (Sweden)

Timothy John Pattiasina

2014-07-01

Full Text Available Advanced Encryption Standard (AES dan Knapsack adalah dua algoritma enkripsi simetris dan asimetris yang paling sering digunakan. Penelitian ini menganalisa kedua algoritma AES dan algoritma Knapsack. Prototipe aplikasi enkripsi email ini dirancang dengan menggabungkan karateristik algoritma AES dan Knapsack untuk memecahkan masalah keamanan email. Algoritma AES digunakan untuk mengenkripsi dan deskripsi email berupa teks atau file, sedangkan Algoritma Knapsack di gunakan untuk mengenkripsi kunci AES. Enkripsi hybrid yang diterapkan pada aplikasi bertujuan untuk menambah keamanan informasi dalam sebuah jaringan.

A high performance hardware implementation image encryption with AES algorithm

Science.gov (United States)

Farmani, Ali; Jafari, Mohamad; Miremadi, Seyed Sohrab

2011-06-01

This paper describes implementation of a high-speed encryption algorithm with high throughput for encrypting the image. Therefore, we select a highly secured symmetric key encryption algorithm AES(Advanced Encryption Standard), in order to increase the speed and throughput using pipeline technique in four stages, control unit based on logic gates, optimal design of multiplier blocks in mixcolumn phase and simultaneous production keys and rounds. Such procedure makes AES suitable for fast image encryption. Implementation of a 128-bit AES on FPGA of Altra company has been done and the results are as follow: throughput, 6 Gbps in 471MHz. The time of encrypting in tested image with 32*32 size is 1.15ms.

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.

Hybrid Approach To Steganography System Based On Quantum Encryption And Chaos Algorithms

Directory of Open Access Journals (Sweden)

ZAID A. ABOD

2018-01-01

Full Text Available A hybrid scheme for secretly embedding image into a dithered multilevel image is presented. This work inputs both a cover image and secret image, which are scrambling and divided into groups to embedded together based on multiple chaos algorithms (Lorenz map, Henon map and Logistic map respectively. Finally, encrypt the embedded images by using one of the quantum cryptography mechanisms, which is quantum one time pad. The experimental results show that the proposed hybrid system successfully embedded images and combine with the quantum cryptography algorithms and gives high efficiency for secure communication.

The experiments and analysis of several selective video encryption methods

Science.gov (United States)

Zhang, Yue; Yang, Cheng; Wang, Lei

2013-07-01

This paper presents four methods for selective video encryption based on the MPEG-2 video compression,including the slices, the I-frames, the motion vectors, and the DCT coefficients. We use the AES encryption method for simulation experiment for the four methods on VS2010 Platform, and compare the video effects and the processing speed of each frame after the video encrypted. The encryption depth can be arbitrarily selected, and design the encryption depth by using the double limit counting method, so the accuracy can be increased.

The Galley Parallel File System

Science.gov (United States)

Nieuwejaar, Nils; Kotz, David

1996-01-01

Most current multiprocessor file systems are designed to use multiple disks in parallel, using the high aggregate bandwidth to meet the growing I/0 requirements of parallel scientific applications. Many multiprocessor file systems provide applications with a conventional Unix-like interface, allowing the application to access multiple disks transparently. This interface conceals the parallelism within the file system, increasing the ease of programmability, but making it difficult or impossible for sophisticated programmers and libraries to use knowledge about their I/O needs to exploit that parallelism. In addition to providing an insufficient interface, most current multiprocessor file systems are optimized for a different workload than they are being asked to support. We introduce Galley, a new parallel file system that is intended to efficiently support realistic scientific multiprocessor workloads. We discuss Galley's file structure and application interface, as well as the performance advantages offered by that interface.

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.

Formalizing a Hierarchical File System

NARCIS (Netherlands)

Hesselink, Wim H.; Lali, M.I.

2009-01-01

In this note, we define an abstract file system as a partial function from (absolute) paths to data. Such a file system determines the set of valid paths. It allows the file system to be read and written at a valid path, and it allows the system to be modified by the Unix operations for removal

The Jade File System. Ph.D. Thesis

Science.gov (United States)

Rao, Herman Chung-Hwa

1991-01-01

File systems have long been the most important and most widely used form of shared permanent storage. File systems in traditional time-sharing systems, such as Unix, support a coherent sharing model for multiple users. Distributed file systems implement this sharing model in local area networks. However, most distributed file systems fail to scale from local area networks to an internet. Four characteristics of scalability were recognized: size, wide area, autonomy, and heterogeneity. Owing to size and wide area, techniques such as broadcasting, central control, and central resources, which are widely adopted by local area network file systems, are not adequate for an internet file system. An internet file system must also support the notion of autonomy because an internet is made up by a collection of independent organizations. Finally, heterogeneity is the nature of an internet file system, not only because of its size, but also because of the autonomy of the organizations in an internet. The Jade File System, which provides a uniform way to name and access files in the internet environment, is presented. Jade is a logical system that integrates a heterogeneous collection of existing file systems, where heterogeneous means that the underlying file systems support different file access protocols. Because of autonomy, Jade is designed under the restriction that the underlying file systems may not be modified. In order to avoid the complexity of maintaining an internet-wide, global name space, Jade permits each user to define a private name space. In Jade's design, we pay careful attention to avoiding unnecessary network messages between clients and file servers in order to achieve acceptable performance. Jade's name space supports two novel features: (1) it allows multiple file systems to be mounted under one direction; and (2) it permits one logical name space to mount other logical name spaces. A prototype of Jade was implemented to examine and validate its

Desain Sistem Keamanan Distribusi Data Dengan Menerapkan XML Encryption Dan XML Signature Berbasis Teknologi Web Service

Directory of Open Access Journals (Sweden)

Slamet Widodo

2012-01-01

Full Text Available Development of information technologies is often misused by an organization or a person to take criminal acts, such as the ability to steal and modify information in the data distribution for evil criminal purpose. The Rural Bank of Boyolali is conducting online financial transactions rather intensively, thus it requiring a security system on the distribution of data and credit transactions for their customer among branches offices to head office. The purpose of this study was to build a security system in credit transactions in Rural Bank of Boyolali for their customers among branches offices to head office. One way in protecting data distribution was used XML encryption and XML signature. The application of encryption technique in XML and digital signature in XML by using web service by using the AES (Advanced Encryption Standard and RSA (Rivest-Shamir-Adleman algorithms. This study was resulted the SOAP (Simple Object Access Protocol message security system, with XML and WSDL (Web Services Description Language, over HTTP (Hypertext Transfer Protocol to protect the customers’ credit transactions from intruders. Analysis of examination indicated that the data size (bytes transferred as results of uncompressed XML encryption were larger than compressed XML Encryption, which leads to significant changes between the data transferred that was the processing time of the compressed data was faster than uncompressed XML encryption.

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

Research on Image Encryption Based on DNA Sequence and Chaos Theory

Science.gov (United States)

Tian Zhang, Tian; Yan, Shan Jun; Gu, Cheng Yan; Ren, Ran; Liao, Kai Xin

2018-04-01

Nowadays encryption is a common technique to protect image data from unauthorized access. In recent years, many scientists have proposed various encryption algorithms based on DNA sequence to provide a new idea for the design of image encryption algorithm. Therefore, a new method of image encryption based on DNA computing technology is proposed in this paper, whose original image is encrypted by DNA coding and 1-D logistic chaotic mapping. First, the algorithm uses two modules as the encryption key. The first module uses the real DNA sequence, and the second module is made by one-dimensional logistic chaos mapping. Secondly, the algorithm uses DNA complementary rules to encode original image, and uses the key and DNA computing technology to compute each pixel value of the original image, so as to realize the encryption of the whole image. Simulation results show that the algorithm has good encryption effect and security.

An analysis of file system and installation of the file management system for NOS operating system

International Nuclear Information System (INIS)

Lee, Young Jai; Park, Sun Hee; Hwang, In Ah; Kim, Hee Kyung

1992-06-01

In this technical report, we analyze NOS file structure for Cyber 170-875 and Cyber 960-31 computer system. We also describe functions, procedure and how-to-operate and how-to-use of VDS. VDS is used to manage large files effectively for Cyber computer system. The purpose of the VDS installation is to increase the virtual disk storage by utilizing magnetic tape, to assist the users of the computer system in managing their files, and to enhance the performance of KAERI Cyber computer system. (Author)

Logic Encryption

Science.gov (United States)

2014-02-01

encryption can also be performed non-iteratively by using a fault simulator that supports multiple stuck-at fault models. 8. REFERENCES [1] KPMG ...www.agmaglobal.org/press_events/press_docs/Counterfeit_WhitePaper_Final.pdf [2] SEMI. (2008) Innovation is at risk as semiconductor equipment and materials

Secure Hybrid Encryption from Weakened Key Encapsulation

NARCIS (Netherlands)

D. Hofheinz (Dennis); E. Kiltz (Eike); A. Menezes

2007-01-01

textabstractWe put forward a new paradigm for building hybrid encryption schemes from constrained chosen-ciphertext secure (CCCA) key-encapsulation mechanisms (KEMs) plus authenticated symmetric encryption. Constrained chosen-ciphertext security is a new security notion for KEMs that we propose. It

Mixed-Media File Systems

NARCIS (Netherlands)

Bosch, H.G.P.

1999-01-01

This thesis addresses the problem of implementing mixed-media storage systems. In this work a mixed-media file system is defined to be a system that stores both conventional (best-effort) file data and real-time continuous-media data. Continuous-media data is usually bulky, and servers storing and

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.

Security of public key encryption technique based on multiple chaotic systems

International Nuclear Information System (INIS)

Wang Kai; Pei Wenjiang; Zou Liuhua; Cheung Yiuming; He Zhenya

2006-01-01

Recently, a new public key encryption technique based on multiple chaotic systems has been proposed [B. Ranjan, Phys. Rev. Lett. 95 (2005) 098702]. This scheme employs m-chaotic systems and a set of linear functions for key exchange over an insecure channel. Security of the proposed algorithm grows as (NP) m , where N, P are the size of the key and the computational complexity of the linear functions respectively. In this Letter, the fundamental weakness of the cryptosystem is pointed out and a successful attack is described. Given the public keys and the initial vector, one can calculate the secret key based on Parseval's theorem. Both theoretical and experimental results show that the attacker can access to the secret key without difficulty. The lack of security discourages the use of such algorithm for practical applications

A two layer chaotic encryption scheme of secure image transmission for DCT precoded OFDM-VLC transmission

Science.gov (United States)

Wang, Zhongpeng; Chen, Fangni; Qiu, Weiwei; Chen, Shoufa; Ren, Dongxiao

2018-03-01

In this paper, a two-layer image encryption scheme for a discrete cosine transform (DCT) precoded orthogonal frequency division multiplexing (OFDM) visible light communication (VLC) system is proposed. Firstly, in the proposed scheme the transmitted image is first encrypted by a chaos scrambling sequence,which is generated from the hybrid 4-D hyper- and Arnold map in the upper-layer. After that, the encrypted image is converted into digital QAM modulation signal, which is re-encrypted by chaos scrambling sequence based on Arnold map in physical layer to further enhance the security of the transmitted image. Moreover, DCT precoding is employed to improve BER performance of the proposed system and reduce the PAPR of OFDM signal. The BER and PAPR performances of the proposed system are evaluated by simulation experiments. The experiment results show that the proposed two-layer chaos scrambling schemes achieve image secure transmission for image-based OFDM VLC. Furthermore, DCT precoding can reduce the PAPR and improve the BER performance of OFDM-based VLC.

Photon-counting multifactor optical encryption and authentication

International Nuclear Information System (INIS)

Pérez-Cabré, E; Millán, M S; Mohammed, E A; Saadon, H L

2015-01-01

The multifactor optical encryption authentication method [Opt. Lett., 31 721-3 (2006)] reinforces optical security by allowing the simultaneous authentication of up to four factors. In this work, the photon-counting imaging technique is applied to the multifactor encrypted function so that a sparse phase-only distribution is generated for the encrypted data. The integration of both techniques permits an increased capacity for signal hiding with simultaneous data reduction for better fulfilling the general requirements of protection, storage and transmission. Cryptanalysis of the proposed method is carried out in terms of chosen-plaintext and chosen-ciphertext attacks. Although the multifactor authentication process is not substantially altered by those attacks, its integration with the photon-counting imaging technique prevents from possible partial disclosure of any encrypted factor, thus increasing the security level of the overall process. Numerical experiments and results are provided and discussed. (paper)

The Global File System

Science.gov (United States)

Soltis, Steven R.; Ruwart, Thomas M.; OKeefe, Matthew T.

1996-01-01

The global file system (GFS) is a prototype design for a distributed file system in which cluster nodes physically share storage devices connected via a network-like fiber channel. Networks and network-attached storage devices have advanced to a level of performance and extensibility so that the previous disadvantages of shared disk architectures are no longer valid. This shared storage architecture attempts to exploit the sophistication of storage device technologies whereas a server architecture diminishes a device's role to that of a simple component. GFS distributes the file system responsibilities across processing nodes, storage across the devices, and file system resources across the entire storage pool. GFS caches data on the storage devices instead of the main memories of the machines. Consistency is established by using a locking mechanism maintained by the storage devices to facilitate atomic read-modify-write operations. The locking mechanism is being prototyped in the Silicon Graphics IRIX operating system and is accessed using standard Unix commands and modules.

PFS: a distributed and customizable file system

OpenAIRE

Bosch, H.G.P.; Mullender, Sape J.

1996-01-01

In this paper we present our ongoing work on the Pegasus File System (PFS), a distributed and customizable file system that can be used for off-line file system experiments and on-line file system storage. PFS is best described as an object-oriented component library from which either a true file system or a file-system simulator can be constructed. Each of the components in the library is easily replaced by another implementation to accommodate a wide range of applications.

GUI implementation of image encryption and decryption using Open CV-Python script on secured TFTP protocol

Science.gov (United States)

Reddy, K. Rasool; Rao, Ch. Madhava

2018-04-01

Currently safety is one of the primary concerns in the transmission of images due to increasing the use of images within the industrial applications. So it's necessary to secure the image facts from unauthorized individuals. There are various strategies are investigated to secure the facts. In that encryption is certainly one of maximum distinguished method. This paper gives a sophisticated Rijndael (AES) algorithm to shield the facts from unauthorized humans. Here Exponential Key Change (EKE) concept is also introduced to exchange the key between client and server. The things are exchange in a network among client and server through a simple protocol is known as Trivial File Transfer Protocol (TFTP). This protocol is used mainly in embedded servers to transfer the data and also provide protection to the data if protection capabilities are integrated. In this paper, implementing a GUI environment for image encryption and decryption. All these experiments carried out on Linux environment the usage of Open CV-Python script.

77 FR 52036 - Privacy Act of 1974; Report of a New System of Records; FDA Records Related to Research...

Science.gov (United States)

2012-08-28

... 2, DHS uses intrusion detection systems to monitor Internet traffic to and from federal computer... personnel. Access to computer files is strictly limited through passwords and user-invisible encryption...

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.

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.

PFS: a distributed and customizable file system

NARCIS (Netherlands)

Bosch, H.G.P.; Mullender, Sape J.

1996-01-01

In this paper we present our ongoing work on the Pegasus File System (PFS), a distributed and customizable file system that can be used for off-line file system experiments and on-line file system storage. PFS is best described as an object-oriented component library from which either a true file

An Improved Piecewise Linear Chaotic Map Based Image Encryption Algorithm

Directory of Open Access Journals (Sweden)

Yuping Hu

2014-01-01

Full Text Available An image encryption algorithm based on improved piecewise linear chaotic map (MPWLCM model was proposed. The algorithm uses the MPWLCM to permute and diffuse plain image simultaneously. Due to the sensitivity to initial key values, system parameters, and ergodicity in chaotic system, two pseudorandom sequences are designed and used in the processes of permutation and diffusion. The order of processing pixels is not in accordance with the index of pixels, but it is from beginning or end alternately. The cipher feedback was introduced in diffusion process. Test results and security analysis show that not only the scheme can achieve good encryption results but also its key space is large enough to resist against brute attack.

Images Encryption Method using Steganographic LSB Method, AES and RSA algorithm

Science.gov (United States)

Moumen, Abdelkader; Sissaoui, Hocine

2017-03-01

Vulnerability of communication of digital images is an extremely important issue nowadays, particularly when the images are communicated through insecure channels. To improve communication security, many cryptosystems have been presented in the image encryption literature. This paper proposes a novel image encryption technique based on an algorithm that is faster than current methods. The proposed algorithm eliminates the step in which the secrete key is shared during the encryption process. It is formulated based on the symmetric encryption, asymmetric encryption and steganography theories. The image is encrypted using a symmetric algorithm, then, the secret key is encrypted by means of an asymmetrical algorithm and it is hidden in the ciphered image using a least significant bits steganographic scheme. The analysis results show that while enjoying the faster computation, our method performs close to optimal in terms of accuracy.

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.

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.

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...

A Layered Searchable Encryption Scheme with Functional Components Independent of Encryption Methods

Science.gov (United States)

Luo, Guangchun; Qin, Ke

2014-01-01

Searchable encryption technique enables the users to securely store and search their documents over the remote semitrusted server, which is especially suitable for protecting sensitive data in the cloud. However, various settings (based on symmetric or asymmetric encryption) and functionalities (ranked keyword query, range query, phrase query, etc.) are often realized by different methods with different searchable structures that are generally not compatible with each other, which limits the scope of application and hinders the functional extensions. We prove that asymmetric searchable structure could be converted to symmetric structure, and functions could be modeled separately apart from the core searchable structure. Based on this observation, we propose a layered searchable encryption (LSE) scheme, which provides compatibility, flexibility, and security for various settings and functionalities. In this scheme, the outputs of the core searchable component based on either symmetric or asymmetric setting are converted to some uniform mappings, which are then transmitted to loosely coupled functional components to further filter the results. In such a way, all functional components could directly support both symmetric and asymmetric settings. Based on LSE, we propose two representative and novel constructions for ranked keyword query (previously only available in symmetric scheme) and range query (previously only available in asymmetric scheme). PMID:24719565

Quantum key distribution via quantum encryption

CERN Document Server

Yong Sheng Zhang; Guang Can Guo

2001-01-01

A quantum key distribution protocol based on quantum encryption is presented in this Brief Report. In this protocol, the previously shared Einstein-Podolsky-Rosen pairs act as the quantum key to encode and decode the classical cryptography key. The quantum key is reusable and the eavesdropper cannot elicit any information from the particle Alice sends to Bob. The concept of quantum encryption is also discussed. (21 refs).

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.

A Novel Image Encryption Scheme Based on Self-Synchronous Chaotic Stream Cipher and Wavelet Transform

Directory of Open Access Journals (Sweden)

Chunlei Fan

2018-06-01

Full Text Available In this paper, a novel image encryption scheme is proposed for the secure transmission of image data. A self-synchronous chaotic stream cipher is designed with the purpose of resisting active attack and ensures the limited error propagation of image data. Two-dimensional discrete wavelet transform and Arnold mapping are used to scramble the pixel value of the original image. A four-dimensional hyperchaotic system with four positive Lyapunov exponents serve as the chaotic sequence generator of the self-synchronous stream cipher in order to enhance the security and complexity of the image encryption system. Finally, the simulation experiment results show that this image encryption scheme is both reliable and secure.

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.

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)

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.

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.

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.

Deceit: A flexible distributed file system

Science.gov (United States)

Siegel, Alex; Birman, Kenneth; Marzullo, Keith

1989-01-01

Deceit, a distributed file system (DFS) being developed at Cornell, focuses on flexible file semantics in relation to efficiency, scalability, and reliability. Deceit servers are interchangeable and collectively provide the illusion of a single, large server machine to any clients of the Deceit service. Non-volatile replicas of each file are stored on a subset of the file servers. The user is able to set parameters on a file to achieve different levels of availability, performance, and one-copy serializability. Deceit also supports a file version control mechanism. In contrast with many recent DFS efforts, Deceit can behave like a plain Sun Network File System (NFS) server and can be used by any NFS client without modifying any client software. The current Deceit prototype uses the ISIS Distributed Programming Environment for all communication and process group management, an approach that reduces system complexity and increases system robustness.

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.

Towards an Information Theoretic Analysis of Searchable Encryption (Extended Version)

NARCIS (Netherlands)

Sedghi, S.; Doumen, J.M.; Hartel, Pieter H.; Jonker, Willem

2008-01-01

Searchable encryption is a technique that allows a client to store data in encrypted form on a curious server, such that data can be retrieved while leaking a minimal amount of information to the server. Many searchable encryption schemes have been proposed and proved secure in their own

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.

Multiple Lookup Table-Based AES Encryption Algorithm Implementation

Science.gov (United States)

Gong, Jin; Liu, Wenyi; Zhang, Huixin

Anew AES (Advanced Encryption Standard) encryption algorithm implementation was proposed in this paper. It is based on five lookup tables, which are generated from S-box(the substitution table in AES). The obvious advantages are reducing the code-size, improving the implementation efficiency, and helping new learners to understand the AES encryption algorithm and GF(28) multiplication which are necessary to correctly implement AES[1]. This method can be applied on processors with word length 32 or above, FPGA and others. And correspondingly we can implement it by VHDL, Verilog, VB and other languages.

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.

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

Improvement of One Quantum Encryption Scheme

Science.gov (United States)

Cao, Zhengjun; Liu, Lihua

2012-01-01

Zhou et al. proposed a quantum encryption scheme based on quantum computation in 2006 [N. Zhou et al., Physica A362 (2006) 305]. Each qubit of the ciphertext is constrained to two pairs of conjugate states. So, its implementation is feasible with the existing technology. But it is inefficient since it entails six key bits to encrypt one message bit, and the resulting ciphertext for one message bit consists of three qubits. In addition, its security cannot be directly reduced to the well-known BB84 protocol. In this paper, we improve it using the technique developed in BB84 protocol. The new scheme entails only two key bits to encrypt one message bit. The resulting ciphertext is just composed of two qubits. It saves about a half cost without the loss of security. Moreover, the new scheme is probabilistic instead of deterministic.

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.

A Colour Image Encryption Scheme Using Permutation-Substitution Based on Chaos

Directory of Open Access Journals (Sweden)

Xing-Yuan Wang

2015-06-01

Full Text Available An encryption scheme for colour images using a spatiotemporal chaotic system is proposed. Initially, we use the R, G and B components of a colour plain-image to form a matrix. Then the matrix is permutated by using zigzag path scrambling. The resultant matrix is then passed through a substitution process. Finally, the ciphered colour image is obtained from the confused matrix. Theoretical analysis and experimental results indicate that the proposed scheme is both secure and practical, which make it suitable for encrypting colour images of any size.

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.

Virtual file system for PSDS

Science.gov (United States)

Runnels, Tyson D.

1993-01-01

This is a case study. It deals with the use of a 'virtual file system' (VFS) for Boeing's UNIX-based Product Standards Data System (PSDS). One of the objectives of PSDS is to store digital standards documents. The file-storage requirements are that the files must be rapidly accessible, stored for long periods of time - as though they were paper, protected from disaster, and accumulative to about 80 billion characters (80 gigabytes). This volume of data will be approached in the first two years of the project's operation. The approach chosen is to install a hierarchical file migration system using optical disk cartridges. Files are migrated from high-performance media to lower performance optical media based on a least-frequency-used algorithm. The optical media are less expensive per character stored and are removable. Vital statistics about the removable optical disk cartridges are maintained in a database. The assembly of hardware and software acts as a single virtual file system transparent to the PSDS user. The files are copied to 'backup-and-recover' media whose vital statistics are also stored in the database. Seventeen months into operation, PSDS is storing 49 gigabytes. A number of operational and performance problems were overcome. Costs are under control. New and/or alternative uses for the VFS are being considered.

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)

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

STP-LWE: A Variant of Learning with Error for a Flexible Encryption

Directory of Open Access Journals (Sweden)

Bo Gao

2014-01-01

Full Text Available We construct a flexible lattice based scheme based on semitensor product learning with errors (STP-LWE, which is a variant of learning with errors problem. We have proved that STP-LWE is hard when LWE is hard. Our scheme is proved to be secure against indistinguishable chosen message attacks, and it can achieve a balance between the security and efficiency in the hierarchical encryption systems. In addition, our scheme is almost as efficient as the dual encryption in GPV08.

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.

Key management of the double random-phase-encoding method using public-key encryption

Science.gov (United States)

Saini, Nirmala; Sinha, Aloka

2010-03-01

Public-key encryption has been used to encode the key of the encryption process. In the proposed technique, an input image has been encrypted by using the double random-phase-encoding method using extended fractional Fourier transform. The key of the encryption process have been encoded by using the Rivest-Shamir-Adelman (RSA) public-key encryption algorithm. The encoded key has then been transmitted to the receiver side along with the encrypted image. In the decryption process, first the encoded key has been decrypted using the secret key and then the encrypted image has been decrypted by using the retrieved key parameters. The proposed technique has advantage over double random-phase-encoding method because the problem associated with the transmission of the key has been eliminated by using public-key encryption. Computer simulation has been carried out to validate the proposed technique.

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.

Homomorphic encryption and secure comparison

DEFF Research Database (Denmark)

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

2008-01-01

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......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...

Information security in data exchange between mobile devices with Android system using RSA encryption

Directory of Open Access Journals (Sweden)

Fernando Solís

2017-02-01

Full Text Available The new styles and ways of life lead to greater use of wireless networks, the mobile device being a tool for data transmission, which are susceptible to threats in the transmission channels in the network. IT security plays a very important role in guaranteeing the availability, privacy and integrity of information, one of the techniques that helps in this task is cryptography, whose foundation is to transform a message so that it is unintelligible except for those who have the Key to decipher it. The research focuses on the use of the RSA algorithm between mobile devices, the encrypted data is sent through communication channels called threads that through formulas and processes executed on the server, will help to execute the encryption and decryption of the data. To carry it out, a prototype for the exchange of data between mobile devices wirelessly was designed and implemented, conducting performance tests with three nodes to improve the security. The results show the efficiency of the algorithm and additionally its functionality, the times of encryption and decryption are fast against the sending of information without any method or algorithm used.

An Intelligent and Fast Chaotic Encryption Using Digital Logic Circuits for Ad-Hoc and Ubiquitous Computing

Directory of Open Access Journals (Sweden)

Ankur Khare

2016-05-01

Full Text Available Delays added by the encryption process represent an overhead for smart computing devices in ad-hoc and ubiquitous computing intelligent systems. Digital Logic Circuits are faster than other computing techniques, so these can be used for fast encryption to minimize processing delays. Chaotic Encryption is more attack-resilient than other encryption techniques. One of the most attractive properties of cryptography is known as an avalanche effect, in which two different keys produce distinct cipher text for the same information. Important properties of chaotic systems are sensitivity to initial conditions and nonlinearity, which makes two similar keys that generate different cipher text a source of confusion. In this paper a novel fast and secure Chaotic Map-based encryption technique using 2’s Compliment (CET-2C has been proposed, which uses a logistic map which implies that a negligible difference in parameters of the map generates different cipher text. Cryptanalysis of the proposed algorithm shows the strength and security of algorithm and keys. Performance of the proposed algorithm has been analyzed in terms of running time, throughput and power consumption. It is to be shown in comparison graphs that the proposed algorithm gave better results compare to different algorithms like AES and some others.

The File System Interface is an Anachronism

OpenAIRE

Ellard, Daniel

2003-01-01

Contemporary file systems implement a set of abstractions and semantics that are suboptimal for many (if not most) purposes. The philosophy of using the simple mechanisms of the file system as the basis for a vast array of higher-level mechanisms leads to inefficient and incorrect implementations. We propose several extensions to the canonical file system model, including explicit support for lock files, indexed files, and resource forks, and the benefit of session semantics for write updates...

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.

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.

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.

A Novel Image Encryption Scheme Based on Clifford Attractor and Noisy Logistic Map for Secure Transferring Images in Navy

Directory of Open Access Journals (Sweden)

Mohadeseh Kanafchian

2017-04-01

In this paper, we first give a brief introduction into chaotic image encryption and then we investigate some important properties and behaviour of the logistic map. The logistic map, aperiodic trajectory, or random-like fluctuation, could not be obtained with some choice of initial condition. Therefore, a noisy logistic map with an additive system noise is introduced. The proposed scheme is based on the extended map of the Clifford strange attractor, where each dimension has a specific role in the encryption process. Two dimensions are used for pixel permutation and the third dimension is used for pixel diffusion. In order to optimize the Clifford encryption system we increase the space key by using the noisy logistic map and a novel encryption scheme based on the Clifford attractor and the noisy logistic map for secure transfer images is proposed. This algorithm consists of two parts: the noisy logistic map shuffle of the pixel position and the pixel value. We use times for shuffling the pixel position and value then we generate the new pixel position and value by the Clifford system. To illustrate the efficiency of the proposed scheme, various types of security analysis are tested. It can be concluded that the proposed image encryption system is a suitable choice for practical applications.

Storage and Retrieval of Encrypted Data Blocks with In-Line Message Authentication Codes

NARCIS (Netherlands)

Bosch, H.G.P.; McLellan Jr, Hubert Rae; Mullender, Sape J.

2007-01-01

Techniques are disclosed for in-line storage of message authentication codes with respective encrypted data blocks. In one aspect, a given data block is encrypted and a message authentication code is generated for the encrypted data block. A target address is determined for storage of the encrypted

Encryption protection for communication satellites

Science.gov (United States)

Sood, D. R.; Hoernig, O. W., Jr.

In connection with the growing importance of the commercial communication satellite systems and the introduction of new technological developments, users and operators of these systems become increasingly concerned with aspects of security. The user community is concerned with maintaining confidentiality and integrity of the information being transmitted over the satellite links, while the satellite operators are concerned about the safety of their assets in space. In response to these concerns, the commercial satellite operators are now taking steps to protect the communication information and the satellites. Thus, communication information is being protected by end-to-end encryption of the customer communication traffic. Attention is given to the selection of the NBS DES algorithm, the command protection systems, and the communication protection systems.

Hiding Techniques for Dynamic Encryption Text based on Corner Point

Science.gov (United States)

Abdullatif, Firas A.; Abdullatif, Alaa A.; al-Saffar, Amna

2018-05-01

Hiding technique for dynamic encryption text using encoding table and symmetric encryption method (AES algorithm) is presented in this paper. The encoding table is generated dynamically from MSB of the cover image points that used as the first phase of encryption. The Harris corner point algorithm is applied on cover image to generate the corner points which are used to generate dynamic AES key to second phase of text encryption. The embedded process in the LSB for the image pixels except the Harris corner points for more robust. Experimental results have demonstrated that the proposed scheme have embedding quality, error-free text recovery, and high value in PSNR.

An Unequal Secure Encryption Scheme for H.264/AVC Video Compression Standard

Science.gov (United States)

Fan, Yibo; Wang, Jidong; Ikenaga, Takeshi; Tsunoo, Yukiyasu; Goto, Satoshi

H.264/AVC is the newest video coding standard. There are many new features in it which can be easily used for video encryption. In this paper, we propose a new scheme to do video encryption for H.264/AVC video compression standard. We define Unequal Secure Encryption (USE) as an approach that applies different encryption schemes (with different security strength) to different parts of compressed video data. This USE scheme includes two parts: video data classification and unequal secure video data encryption. Firstly, we classify the video data into two partitions: Important data partition and unimportant data partition. Important data partition has small size with high secure protection, while unimportant data partition has large size with low secure protection. Secondly, we use AES as a block cipher to encrypt the important data partition and use LEX as a stream cipher to encrypt the unimportant data partition. AES is the most widely used symmetric cryptography which can ensure high security. LEX is a new stream cipher which is based on AES and its computational cost is much lower than AES. In this way, our scheme can achieve both high security and low computational cost. Besides the USE scheme, we propose a low cost design of hybrid AES/LEX encryption module. Our experimental results show that the computational cost of the USE scheme is low (about 25% of naive encryption at Level 0 with VEA used). The hardware cost for hybrid AES/LEX module is 4678 Gates and the AES encryption throughput is about 50Mbps.

Noise removing in encrypted color images by statistical analysis

Science.gov (United States)

Islam, N.; Puech, W.

2012-03-01

Cryptographic techniques are used to secure confidential data from unauthorized access but these techniques are very sensitive to noise. A single bit change in encrypted data can have catastrophic impact over the decrypted data. This paper addresses the problem of removing bit error in visual data which are encrypted using AES algorithm in the CBC mode. In order to remove the noise, a method is proposed which is based on the statistical analysis of each block during the decryption. The proposed method exploits local statistics of the visual data and confusion/diffusion properties of the encryption algorithm to remove the errors. Experimental results show that the proposed method can be used at the receiving end for the possible solution for noise removing in visual data in encrypted domain.

Cryptanalysis of "an improvement over an image encryption method based on total shuffling"

Science.gov (United States)

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

2015-09-01

In the past two decades, several image encryption algorithms based on chaotic systems had been proposed. Many of the proposed algorithms are meant to improve other chaos based and conventional cryptographic algorithms. Whereas, many of the proposed improvement methods suffer from serious security problems. In this paper, the security of the recently proposed improvement method for a chaos-based image encryption algorithm is analyzed. The results indicate the weakness of the analyzed algorithm against chosen plain-text.

Reversible Integer Wavelet Transform for the Joint of Image Encryption and Watermarking

Directory of Open Access Journals (Sweden)

Bin Wang

2015-01-01

Full Text Available In recent years, signal processing in the encrypted domain has attracted considerable research interest, especially embedding watermarking in encrypted image. In this work, a novel joint of image encryption and watermarking based on reversible integer wavelet transform is proposed. Firstly, the plain-image is encrypted by chaotic maps and reversible integer wavelet transform. Then the lossless watermarking is embedded in the encrypted image by reversible integer wavelet transform and histogram modification. Finally an encrypted image containing watermarking is obtained by the inverse integer wavelet transform. What is more, the original image and watermarking can be completely recovered by inverse process. Numerical experimental results and comparing with previous works show that the proposed scheme possesses higher security and embedding capacity than previous works. It is suitable for protecting the image information.

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.

Frontpage and Dreamweaver users must use encryption

CERN Multimedia

Web Services Team

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

Optimizing Instruction Scheduling and Register Allocation for Register-File-Connected Clustered VLIW Architectures

Science.gov (United States)

Tang, Haijing; Wang, Siye; Zhang, Yanjun

2013-01-01

Clustering has become a common trend in very long instruction words (VLIW) architecture to solve the problem of area, energy consumption, and design complexity. Register-file-connected clustered (RFCC) VLIW architecture uses the mechanism of global register file to accomplish the inter-cluster data communications, thus eliminating the performance and energy consumption penalty caused by explicit inter-cluster data move operations in traditional bus-connected clustered (BCC) VLIW architecture. However, the limit number of access ports to the global register file has become an issue which must be well addressed; otherwise the performance and energy consumption would be harmed. In this paper, we presented compiler optimization techniques for an RFCC VLIW architecture called Lily, which is designed for encryption systems. These techniques aim at optimizing performance and energy consumption for Lily architecture, through appropriate manipulation of the code generation process to maintain a better management of the accesses to the global register file. All the techniques have been implemented and evaluated. The result shows that our techniques can significantly reduce the penalty of performance and energy consumption due to access port limitation of global register file. PMID:23970841

Optimizing Instruction Scheduling and Register Allocation for Register-File-Connected Clustered VLIW Architectures

Directory of Open Access Journals (Sweden)

Haijing Tang

2013-01-01

Full Text Available Clustering has become a common trend in very long instruction words (VLIW architecture to solve the problem of area, energy consumption, and design complexity. Register-file-connected clustered (RFCC VLIW architecture uses the mechanism of global register file to accomplish the inter-cluster data communications, thus eliminating the performance and energy consumption penalty caused by explicit inter-cluster data move operations in traditional bus-connected clustered (BCC VLIW architecture. However, the limit number of access ports to the global register file has become an issue which must be well addressed; otherwise the performance and energy consumption would be harmed. In this paper, we presented compiler optimization techniques for an RFCC VLIW architecture called Lily, which is designed for encryption systems. These techniques aim at optimizing performance and energy consumption for Lily architecture, through appropriate manipulation of the code generation process to maintain a better management of the accesses to the global register file. All the techniques have been implemented and evaluated. The result shows that our techniques can significantly reduce the penalty of performance and energy consumption due to access port limitation of global register file.

Apically extruded dentin debris by reciprocating single-file and multi-file rotary system.

Science.gov (United States)

De-Deus, Gustavo; Neves, Aline; Silva, Emmanuel João; Mendonça, Thais Accorsi; Lourenço, Caroline; Calixto, Camila; Lima, Edson Jorge Moreira

2015-03-01

This study aims to evaluate the apical extrusion of debris by the two reciprocating single-file systems: WaveOne and Reciproc. Conventional multi-file rotary system was used as a reference for comparison. The hypotheses tested were (i) the reciprocating single-file systems extrude more than conventional multi-file rotary system and (ii) the reciprocating single-file systems extrude similar amounts of dentin debris. After solid selection criteria, 80 mesial roots of lower molars were included in the present study. The use of four different instrumentation techniques resulted in four groups (n = 20): G1 (hand-file technique), G2 (ProTaper), G3 (WaveOne), and G4 (Reciproc). The apparatus used to evaluate the collection of apically extruded debris was typical double-chamber collector. Statistical analysis was performed for multiple comparisons. No significant difference was found in the amount of the debris extruded between the two reciprocating systems. In contrast, conventional multi-file rotary system group extruded significantly more debris than both reciprocating groups. Hand instrumentation group extruded significantly more debris than all other groups. The present results yielded favorable input for both reciprocation single-file systems, inasmuch as they showed an improved control of apically extruded debris. Apical extrusion of debris has been studied extensively because of its clinical relevance, particularly since it may cause flare-ups, originated by the introduction of bacteria, pulpal tissue, and irrigating solutions into the periapical tissues.

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...

Protecting your files on the DFS file system

CERN Multimedia

Computer Security Team

2011-01-01

The Windows Distributed File System (DFS) hosts user directories for all NICE users plus many more data.    Files can be accessed from anywhere, via a dedicated web portal (http://cern.ch/dfs). Due to the ease of access to DFS with in CERN it is of utmost importance to properly protect access to sensitive data. As the use of DFS access control mechanisms is not obvious to all users, passwords, certificates or sensitive files might get exposed. At least this happened in past to the Andrews File System (AFS) - the Linux equivalent to DFS) - and led to bad publicity due to a journalist accessing supposedly "private" AFS folders (SonntagsZeitung 2009/11/08). This problem does not only affect the individual user but also has a bad impact on CERN's reputation when it comes to IT security. Therefore, all departments and LHC experiments agreed recently to apply more stringent protections to all DFS user folders. The goal of this data protection policy is to assist users in pro...

Protecting your files on the AFS file system

CERN Multimedia

2011-01-01

The Andrew File System is a world-wide distributed file system linking hundreds of universities and organizations, including CERN. Files can be accessed from anywhere, via dedicated AFS client programs or via web interfaces that export the file contents on the web. Due to the ease of access to AFS it is of utmost importance to properly protect access to sensitive data in AFS. As the use of AFS access control mechanisms is not obvious to all users, passwords, private SSH keys or certificates have been exposed in the past. In one specific instance, this also led to bad publicity due to a journalist accessing supposedly "private" AFS folders (SonntagsZeitung 2009/11/08). This problem does not only affect the individual user but also has a bad impact on CERN's reputation when it comes to IT security. Therefore, all departments and LHC experiments agreed in April 2010 to apply more stringent folder protections to all AFS user folders. The goal of this data protection policy is to assist users in...

Storage of sparse files using parallel log-structured file system

Science.gov (United States)

Bent, John M.; Faibish, Sorin; Grider, Gary; Torres, Aaron

2017-11-07

A sparse file is stored without holes by storing a data portion of the sparse file using a parallel log-structured file system; and generating an index entry for the data portion, the index entry comprising a logical offset, physical offset and length of the data portion. The holes can be restored to the sparse file upon a reading of the sparse file. The data portion can be stored at a logical end of the sparse file. Additional storage efficiency can optionally be achieved by (i) detecting a write pattern for a plurality of the data portions and generating a single patterned index entry for the plurality of the patterned data portions; and/or (ii) storing the patterned index entries for a plurality of the sparse files in a single directory, wherein each entry in the single directory comprises an identifier of a corresponding sparse file.

Fast Video Encryption Using the H.264 Error Propagation Property for Smart Mobile Devices

Directory of Open Access Journals (Sweden)

Yongwha Chung

2015-04-01

Full Text Available In transmitting video data securely over Video Sensor Networks (VSNs, since mobile handheld devices have limited resources in terms of processor clock speed and battery size, it is necessary to develop an efficient method to encrypt video data to meet the increasing demand for secure connections. Selective encryption methods can reduce the amount of computation needed while satisfying high-level security requirements. This is achieved by selecting an important part of the video data and encrypting it. In this paper, to ensure format compliance and security, we propose a special encryption method for H.264, which encrypts only the DC/ACs of I-macroblocks and the motion vectors of P-macroblocks. In particular, the proposed new selective encryption method exploits the error propagation property in an H.264 decoder and improves the collective performance by analyzing the tradeoff between the visual security level and the processing speed compared to typical selective encryption methods (i.e., I-frame, P-frame encryption, and combined I-/P-frame encryption. Experimental results show that the proposed method can significantly reduce the encryption workload without any significant degradation of visual security.

Computer Forensics Method in Analysis of Files Timestamps in Microsoft Windows Operating System and NTFS File System

Directory of Open Access Journals (Sweden)

Vesta Sergeevna Matveeva

2013-02-01

Full Text Available All existing file browsers displays 3 timestamps for every file in file system NTFS. Nowadays there are a lot of utilities that can manipulate temporal attributes to conceal the traces of file using. However every file in NTFS has 8 timestamps that are stored in file record and used in detecting the fact of attributes substitution. The authors suggest a method of revealing original timestamps after replacement and automated variant of it in case of a set of files.

A Memory Efficient Network Encryption Scheme

Science.gov (United States)

El-Fotouh, Mohamed Abo; Diepold, Klaus

In this paper, we studied the two widely used encryption schemes in network applications. Shortcomings have been found in both schemes, as these schemes consume either more memory to gain high throughput or low memory with low throughput. The need has aroused for a scheme that has low memory requirements and in the same time possesses high speed, as the number of the internet users increases each day. We used the SSM model [1], to construct an encryption scheme based on the AES. The proposed scheme possesses high throughput together with low memory requirements.

Innovative hyperchaotic encryption algorithm for compressed video

Science.gov (United States)

Yuan, Chun; Zhong, Yuzhuo; Yang, Shiqiang

2002-12-01

It is accepted that stream cryptosystem can achieve good real-time performance and flexibility which implements encryption by selecting few parts of the block data and header information of the compressed video stream. Chaotic random number generator, for example Logistics Map, is a comparatively promising substitute, but it is easily attacked by nonlinear dynamic forecasting and geometric information extracting. In this paper, we present a hyperchaotic cryptography scheme to encrypt the compressed video, which integrates Logistics Map with Z(232 - 1) field linear congruential algorithm to strengthen the security of the mono-chaotic cryptography, meanwhile, the real-time performance and flexibility of the chaotic sequence cryptography are maintained. It also integrates with the dissymmetrical public-key cryptography and implements encryption and identity authentification on control parameters at initialization phase. In accord with the importance of data in compressed video stream, encryption is performed in layered scheme. In the innovative hyperchaotic cryptography, the value and the updating frequency of control parameters can be changed online to satisfy the requirement of the network quality, processor capability and security requirement. The innovative hyperchaotic cryprography proves robust security by cryptoanalysis, shows good real-time performance and flexible implement capability through the arithmetic evaluating and test.

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.

Encryption of covert information into multiple statistical distributions

International Nuclear Information System (INIS)

Venkatesan, R.C.

2007-01-01

A novel strategy to encrypt covert information (code) via unitary projections into the null spaces of ill-conditioned eigenstructures of multiple host statistical distributions, inferred from incomplete constraints, is presented. The host pdf's are inferred using the maximum entropy principle. The projection of the covert information is dependent upon the pdf's of the host statistical distributions. The security of the encryption/decryption strategy is based on the extreme instability of the encoding process. A self-consistent procedure to derive keys for both symmetric and asymmetric cryptography is presented. The advantages of using a multiple pdf model to achieve encryption of covert information are briefly highlighted. Numerical simulations exemplify the efficacy of the model

Protect sensitive data with lightweight memory encryption

Science.gov (United States)

Zhou, Hongwei; Yuan, Jinhui; Xiao, Rui; Zhang, Kai; Sun, Jingyao

2018-04-01

Since current commercial processor is not able to deal with the data in the cipher text, the sensitive data have to be exposed in the memory. It leaves a window for the adversary. To protect the sensitive data, a direct idea is to encrypt the data when the processor does not access them. On the observation, we have developed a lightweight memory encryption, called LeMe, to protect the sensitive data in the application. LeMe marks the sensitive data in the memory with the page table entry, and encrypts the data in their free time. LeMe is built on the Linux with a 3.17.6 kernel, and provides four user interfaces as dynamic link library. Our evaluations show LeMe is effective to protect the sensitive data and incurs an acceptable performance overhead.

Secure positioning technique based on encrypted visible light map for smart indoor service

Science.gov (United States)

Lee, Yong Up; Jung, Gillyoung

2018-03-01

Indoor visible light (VL) positioning systems for smart indoor services are negatively affected by both cochannel interference from adjacent light sources and VL reception position irregularity in the three-dimensional (3-D) VL channel. A secure positioning methodology based on a two-dimensional (2-D) encrypted VL map is proposed, implemented in prototypes of the specific positioning system, and analyzed based on performance tests. The proposed positioning technique enhances the positioning performance by more than 21.7% compared to the conventional method in real VL positioning tests. Further, the pseudonoise code is found to be the optimal encryption key for secure VL positioning for this smart indoor service.

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

Small file aggregation in a parallel computing system

Science.gov (United States)

Faibish, Sorin; Bent, John M.; Tzelnic, Percy; Grider, Gary; Zhang, Jingwang

2014-09-02

Techniques are provided for small file aggregation in a parallel computing system. An exemplary method for storing a plurality of files generated by a plurality of processes in a parallel computing system comprises aggregating the plurality of files into a single aggregated file; and generating metadata for the single aggregated file. The metadata comprises an offset and a length of each of the plurality of files in the single aggregated file. The metadata can be used to unpack one or more of the files from the single aggregated file.

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.

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.

MR-AFS: a global hierarchical file-system

International Nuclear Information System (INIS)

Reuter, H.

2000-01-01

The next generation of fusion experiments will use object-oriented technology creating the need for world wide sharing of an underlying hierarchical file-system. The Andrew file system (AFS) is a well known and widely spread global distributed file-system. Multiple-resident-AFS (MR-AFS) combines the features of AFS with hierarchical storage management systems. Files in MR-AFS therefore may be migrated on secondary storage, such as roboted tape libraries. MR-AFS is in use at IPP for the current experiments and data originating from super-computer applications. Experiences and scalability issues are discussed

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.

Optical image encryption method based on incoherent imaging and polarized light encoding

Science.gov (United States)

Wang, Q.; Xiong, D.; Alfalou, A.; Brosseau, C.

2018-05-01

We propose an incoherent encoding system for image encryption based on a polarized encoding method combined with an incoherent imaging. Incoherent imaging is the core component of this proposal, in which the incoherent point-spread function (PSF) of the imaging system serves as the main key to encode the input intensity distribution thanks to a convolution operation. An array of retarders and polarizers is placed on the input plane of the imaging structure to encrypt the polarized state of light based on Mueller polarization calculus. The proposal makes full use of randomness of polarization parameters and incoherent PSF so that a multidimensional key space is generated to deal with illegal attacks. Mueller polarization calculus and incoherent illumination of imaging structure ensure that only intensity information is manipulated. Another key advantage is that complicated processing and recording related to a complex-valued signal are avoided. The encoded information is just an intensity distribution, which is advantageous for data storage and transition because information expansion accompanying conventional encryption methods is also avoided. The decryption procedure can be performed digitally or using optoelectronic devices. Numerical simulation tests demonstrate the validity of the proposed scheme.

An Improved Image Encryption Algorithm Based on Cyclic Rotations and Multiple Chaotic Sequences: Application to Satellite Images

Directory of Open Access Journals (Sweden)

MADANI Mohammed

2017-10-01

Full Text Available In this paper, a new satellite image encryption algorithm based on the combination of multiple chaotic systems and a random cyclic rotation technique is proposed. Our contribution consists in implementing three different chaotic maps (logistic, sine, and standard combined to improve the security of satellite images. Besides enhancing the encryption, the proposed algorithm also focuses on advanced efficiency of the ciphered images. Compared with classical encryption schemes based on multiple chaotic maps and the Rubik's cube rotation, our approach has not only the same merits of chaos systems like high sensitivity to initial values, unpredictability, and pseudo-randomness, but also other advantages like a higher number of permutations, better performances in Peak Signal to Noise Ratio (PSNR and a Maximum Deviation (MD.

Improving File System Performance by Striping

Science.gov (United States)

Lam, Terance L.; Kutler, Paul (Technical Monitor)

1998-01-01

This document discusses the performance and advantages of striped file systems on the SGI AD workstations. Performance of several striped file system configurations are compared and guidelines for optimal striping are recommended.

Efficient Multi-keyword Ranked Search over Outsourced Cloud Data based on Homomorphic Encryption

Directory of Open Access Journals (Sweden)

Nie Mengxi

2016-01-01

Full Text Available With the development of cloud computing, more and more data owners are motivated to outsource their data to the cloud server for great flexibility and less saving expenditure. Because the security of outsourced data must be guaranteed, some encryption methods should be used which obsoletes traditional data utilization based on plaintext, e.g. keyword search. To solve the search of encrypted data, some schemes were proposed to solve the search of encrypted data, e.g. top-k single or multiple keywords retrieval. However, the efficiency of these proposed schemes is not high enough to be impractical in the cloud computing. In this paper, we propose a new scheme based on homomorphic encryption to solve this challenging problem of privacy-preserving efficient multi-keyword ranked search over outsourced cloud data. In our scheme, the inner product is adopted to measure the relevance scores and the technique of relevance feedback is used to reflect the search preference of the data users. Security analysis shows that the proposed scheme can meet strict privacy requirements for such a secure cloud data utilization system. Performance evaluation demonstrates that the proposed scheme can achieve low overhead on both computation and communication.

Additively homomorphic encryption with a double decryption mechanism, revisited

NARCIS (Netherlands)

Peter, Andreas; Kronberg, M.; Trei, W.; Katzenbeisser, S.

We revisit the notion of additively homomorphic encryption with a double decryption mechanism (DD-PKE), which allows for additions in the encrypted domain while having a master decryption procedure that can decrypt all properly formed ciphertexts by using a special master secret. This type of

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.

A novel algorithm for image encryption based on mixture of chaotic maps

International Nuclear Information System (INIS)

Behnia, S.; Akhshani, A.; Mahmodi, H.; Akhavan, A.

2008-01-01

Chaos-based encryption appeared recently in the early 1990s as an original application of nonlinear dynamics in the chaotic regime. In this paper, an implementation of digital image encryption scheme based on the mixture of chaotic systems is reported. The chaotic cryptography technique used in this paper is a symmetric key cryptography. In this algorithm, a typical coupled map was mixed with a one-dimensional chaotic map and used for high degree security image encryption while its speed is acceptable. The proposed algorithm is described in detail, along with its security analysis and implementation. The experimental results based on mixture of chaotic maps approves the effectiveness of the proposed method and the implementation of the algorithm. This mixture application of chaotic maps shows advantages of large key space and high-level security. The ciphertext generated by this method is the same size as the plaintext and is suitable for practical use in the secure transmission of confidential information over the Internet

Hardware stream cipher with controllable chaos generator for colour image encryption

KAUST Repository

Barakat, Mohamed L.; Mansingka, Abhinav S.; Radwan, Ahmed Gomaa; Salama, Khaled N.

2014-01-01

This study presents hardware realisation of chaos-based stream cipher utilised for image encryption applications. A third-order chaotic system with signum non-linearity is implemented and a new post processing technique is proposed to eliminate

Storing files in a parallel computing system using list-based index to identify replica files

Science.gov (United States)

Faibish, Sorin; Bent, John M.; Tzelnic, Percy; Zhang, Zhenhua; Grider, Gary

2015-07-21

Improved techniques are provided for storing files in a parallel computing system using a list-based index to identify file replicas. A file and at least one replica of the file are stored in one or more storage nodes of the parallel computing system. An index for the file comprises at least one list comprising a pointer to a storage location of the file and a storage location of the at least one replica of the file. The file comprises one or more of a complete file and one or more sub-files. The index may also comprise a checksum value for one or more of the file and the replica(s) of the file. The checksum value can be evaluated to validate the file and/or the file replica(s). A query can be processed using the list.

Securing Voice over IP Conferencing with Decentralized Group Encryption

Science.gov (United States)

2007-09-04

exchanged using 1024 bit RSA encryption. Moreover, Skype allows encrypted conferences to take place as well. On this basis, Skype has a number of...32] Internet Engineering Task Force (IETF). RFC 768 : “User Datagram Protocol,” Aug 1980. [33] Internet Engineering Task Force (IETF). RFC 791

Simultaneous optical image compression and encryption using error-reduction phase retrieval algorithm

International Nuclear Information System (INIS)

Liu, Wei; Liu, Shutian; Liu, Zhengjun

2015-01-01

We report a simultaneous image compression and encryption scheme based on solving a typical optical inverse problem. The secret images to be processed are multiplexed as the input intensities of a cascaded diffractive optical system. At the output plane, a compressed complex-valued data with a lot fewer measurements can be obtained by utilizing error-reduction phase retrieval algorithm. The magnitude of the output image can serve as the final ciphertext while its phase serves as the decryption key. Therefore the compression and encryption are simultaneously completed without additional encoding and filtering operations. The proposed strategy can be straightforwardly applied to the existing optical security systems that involve diffraction and interference. Numerical simulations are performed to demonstrate the validity and security of the proposal. (paper)

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.

Optical image encryption using multilevel Arnold transform and noninterferometric imaging

Science.gov (United States)

Chen, Wen; Chen, Xudong

2011-11-01

Information security has attracted much current attention due to the rapid development of modern technologies, such as computer and internet. We propose a novel method for optical image encryption using multilevel Arnold transform and rotatable-phase-mask noninterferometric imaging. An optical image encryption scheme is developed in the gyrator transform domain, and one phase-only mask (i.e., phase grating) is rotated and updated during image encryption. For the decryption, an iterative retrieval algorithm is proposed to extract high-quality plaintexts. Conventional encoding methods (such as digital holography) have been proven vulnerably to the attacks, and the proposed optical encoding scheme can effectively eliminate security deficiency and significantly enhance cryptosystem security. The proposed strategy based on the rotatable phase-only mask can provide a new alternative for data/image encryption in the noninterferometric imaging.

DMFS: A Data Migration File System for NetBSD

Science.gov (United States)

Studenmund, William

2000-01-01

I have recently developed DMFS, a Data Migration File System, for NetBSD. This file system provides kernel support for the data migration system being developed by my research group at NASA/Ames. The file system utilizes an underlying file store to provide the file backing, and coordinates user and system access to the files. It stores its internal metadata in a flat file, which resides on a separate file system. This paper will first describe our data migration system to provide a context for DMFS, then it will describe DMFS. It also will describe the changes to NetBSD needed to make DMFS work. Then it will give an overview of the file archival and restoration procedures, and describe how some typical user actions are modified by DMFS. Lastly, the paper will present simple performance measurements which indicate that there is little performance loss due to the use of the DMFS layer.

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...

Flexibility and Performance of Parallel File Systems

Science.gov (United States)

Kotz, David; Nieuwejaar, Nils

1996-01-01

As we gain experience with parallel file systems, it becomes increasingly clear that a single solution does not suit all applications. For example, it appears to be impossible to find a single appropriate interface, caching policy, file structure, or disk-management strategy. Furthermore, the proliferation of file-system interfaces and abstractions make applications difficult to port. We propose that the traditional functionality of parallel file systems be separated into two components: a fixed core that is standard on all platforms, encapsulating only primitive abstractions and interfaces, and a set of high-level libraries to provide a variety of abstractions and application-programmer interfaces (API's). We present our current and next-generation file systems as examples of this structure. Their features, such as a three-dimensional file structure, strided read and write interfaces, and I/O-node programs, are specifically designed with the flexibility and performance necessary to support a wide range of applications.

Hierarchical multiple binary image encryption based on a chaos and phase retrieval algorithm in the Fresnel domain

International Nuclear Information System (INIS)

Wang, Zhipeng; Hou, Chenxia; Lv, Xiaodong; Wang, Hongjuan; Gong, Qiong; Qin, Yi

2016-01-01

Based on the chaos and phase retrieval algorithm, a hierarchical multiple binary image encryption is proposed. In the encryption process, each plaintext is encrypted into a diffraction intensity pattern by two chaos-generated random phase masks (RPMs). Thereafter, the captured diffraction intensity patterns are partially selected by different binary masks and then combined together to form a single intensity pattern. The combined intensity pattern is saved as ciphertext. For decryption, an iterative phase retrieval algorithm is performed, in which a support constraint in the output plane and a median filtering operation are utilized to achieve a rapid convergence rate without a stagnation problem. The proposed scheme has a simple optical setup and large encryption capacity. In particular, it is well suited for constructing a hierarchical security system. The security and robustness of the proposal are also investigated. (letter)

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

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.

Design and Implementation of a Metadata-rich File System

Energy Technology Data Exchange (ETDEWEB)

Ames, S; Gokhale, M B; Maltzahn, C

2010-01-19

Despite continual improvements in the performance and reliability of large scale file systems, the management of user-defined file system metadata has changed little in the past decade. The mismatch between the size and complexity of large scale data stores and their ability to organize and query their metadata has led to a de facto standard in which raw data is stored in traditional file systems, while related, application-specific metadata is stored in relational databases. This separation of data and semantic metadata requires considerable effort to maintain consistency and can result in complex, slow, and inflexible system operation. To address these problems, we have developed the Quasar File System (QFS), a metadata-rich file system in which files, user-defined attributes, and file relationships are all first class objects. In contrast to hierarchical file systems and relational databases, QFS defines a graph data model composed of files and their relationships. QFS incorporates Quasar, an XPATH-extended query language for searching the file system. Results from our QFS prototype show the effectiveness of this approach. Compared to the de facto standard, the QFS prototype shows superior ingest performance and comparable query performance on user metadata-intensive operations and superior performance on normal file metadata operations.

Dynamic Non-Hierarchical File Systems for Exascale Storage

Energy Technology Data Exchange (ETDEWEB)

Long, Darrell E. [Univ. of California, Santa Cruz, CA (United States); Miller, Ethan L [Univ. of California, Santa Cruz, CA (United States)

2015-02-24

This constitutes the final report for “Dynamic Non-Hierarchical File Systems for Exascale Storage”. The ultimate goal of this project was to improve data management in scientific computing and high-end computing (HEC) applications, and to achieve this goal we proposed: to develop the first, HEC-targeted, file system featuring rich metadata and provenance collection, extreme scalability, and future storage hardware integration as core design goals, and to evaluate and develop a flexible non-hierarchical file system interface suitable for providing more powerful and intuitive data management interfaces to HEC and scientific computing users. Data management is swiftly becoming a serious problem in the scientific community – while copious amounts of data are good for obtaining results, finding the right data is often daunting and sometimes impossible. Scientists participating in a Department of Energy workshop noted that most of their time was spent “...finding, processing, organizing, and moving data and it’s going to get much worse”. Scientists should not be forced to become data mining experts in order to retrieve the data they want, nor should they be expected to remember the naming convention they used several years ago for a set of experiments they now wish to revisit. Ideally, locating the data you need would be as easy as browsing the web. Unfortunately, existing data management approaches are usually based on hierarchical naming, a 40 year-old technology designed to manage thousands of files, not exabytes of data. Today’s systems do not take advantage of the rich array of metadata that current high-end computing (HEC) file systems can gather, including content-based metadata and provenance1 information. As a result, current metadata search approaches are typically ad hoc and often work by providing a parallel management system to the “main” file system, as is done in Linux (the locate utility), personal computers, and enterprise search

Improved Image Encryption for Real-Time Application over Wireless Communication Networks using Hybrid Cryptography Technique

Directory of Open Access Journals (Sweden)

Kazeem B. Adedeji

2016-12-01

Full Text Available Advances in communication networks have enabled organization to send confidential data such as digital images over wireless networks. However, the broadcast nature of wireless communication channel has made it vulnerable to attack from eavesdroppers. We have developed a hybrid cryptography technique, and we present its application to digital images as a means of improving the security of digital image for transmission over wireless communication networks. The hybrid technique uses a combination of a symmetric (Data Encryption Standard and asymmetric (Rivest Shamir Adleman cryptographic algorithms to secure data to be transmitted between different nodes of a wireless network. Three different image samples of type jpeg, png and jpg were tested using this technique. The results obtained showed that the hybrid system encrypt the images with minimal simulation time, and high throughput. More importantly, there is no relation or information between the original images and their encrypted form, according to Shannon’s definition of perfect security, thereby making the system much more secure.

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 encryption modes, three are inherently sequential: CBC, CFB, and OFB. This inhibits the advantage of using AES-NI significantly. Similar observations apply to CMAC, CCM and a great deal of other modes. We address this issue by proposing the comb scheduler – a fast scheduling algorithm based on an efficient....... We observe a drastic speed-up of factor 5 for NIST’s CBC, CFB, OFB and CMAC performing around 0.88 cpb. Surprisingly, contrary to the entire body of previous performance analysis, the throughput of the authenticated encryption (AE) mode CCM gets very close to that of GCM and OCB3, with about 1.64 cpb...

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.

Collective operations in a file system based execution model

Science.gov (United States)

Shinde, Pravin; Van Hensbergen, Eric

2013-02-19

A mechanism is provided for group communications using a MULTI-PIPE synthetic file system. A master application creates a multi-pipe synthetic file in the MULTI-PIPE synthetic file system, the master application indicating a multi-pipe operation to be performed. The master application then writes a header-control block of the multi-pipe synthetic file specifying at least one of a multi-pipe synthetic file system name, a message type, a message size, a specific destination, or a specification of the multi-pipe operation. Any other application participating in the group communications then opens the same multi-pipe synthetic file. A MULTI-PIPE file system module then implements the multi-pipe operation as identified by the master application. The master application and the other applications then either read or write operation messages to the multi-pipe synthetic file and the MULTI-PIPE synthetic file system module performs appropriate actions.

Distributing File-Based Data to Remote Sites Within the BABAR Collaboration

International Nuclear Information System (INIS)

Gowdy, Stephen J.

2002-01-01

BABAR [1] uses two formats for its data: Objectivity database and root [2] files. This poster concerns the distribution of the latter--for Objectivity data see [3]. The BABAR analysis data is stored in root files--one per physics run and analysis selection channel--maintained in a large directory tree. Currently BABAR has more than 4.5 TBytes in 200,000 root files. This data is (mostly) produced at SLAC, but is required for analysis at universities and research centers throughout the us and Europe. Two basic problems confront us when we seek to import bulk data from slac to an institute's local storage via the network. We must determine which files must be imported (depending on the local site requirements and which files have already been imported), and we must make the optimum use of the network when transferring the data. Basic ftp-like tools (ftp, scp, etc) do not attempt to solve the first problem. More sophisticated tools like rsync [4], the widely-used mirror/synchronization program, compare local and remote file systems, checking for changes (based on file date, size and, if desired, an elaborate checksum) in order to only copy new or modified files. However rsync allows for only limited file selection. Also when, as in BABAR, an extremely large directory structure must be scanned, rsync can take several hours just to determine which files need to be copied. Although rsync (and scp) provides on-the-fly compression, it does not allow us to optimize the network transfer by using multiple streams, adjusting the tcp window size, or separating encrypted authentication from unencrypted data channels

Distributing file-based data to remote sites within the BABAR collaboration

International Nuclear Information System (INIS)

Adye, T.; Dorigo, A.; Forti, A.; Leonardi, E.

2001-01-01

BABAR uses two formats for its data: Objectivity database and ROOT files. This poster concerns the distribution of the latter--for Objectivity data see. The BABAR analysis data is stored in ROOT files--one per physics run and analysis selection channel-maintained in a large directory tree. Currently BABAR has more than 4.5 TBytes in 200,00- ROOT files. This data is (mostly) produced at SLAC, but is required for analysis at universities and research centres throughout the US and Europe. Two basic problems confront us when we seek to import bulk data from SLAC to an institute's local storage via the network. We must determine which files must be imported (depending on the local site requirements and which files have already been imported), and the authors must make the optimum use of the network when transferring the data. Basic ftp-like tools (ftp, scp, etc) do not attempt to solve the first problem. More sophisticated tools like rsync, the widely-used mirror/synchronisation program, compare local and remote file systems, checking for changes (based on file date, size and, if desired, an elaborate checksum) in order to only copy new or modified files. However rsync allows for only limited file selection. Also when, as in BABAR, an extremely large directory structure must be scanned, rsync can take several hours just to determine which files need to be copied. Although rsync (and scp) provides on-the-fly compression, it does not allow us to optimise the network transfer by using multiple streams, adjusting the TCP window size, or separating encrypted authentication from unencrypted data channels

Optical image encryption using fresnel zone plate mask based on fast walsh hadamard transform

Science.gov (United States)

Khurana, Mehak; Singh, Hukum

2018-05-01

A new symmetric encryption technique using Fresnel Zone Plate (FZP) based on Fast Walsh Hadamard Transform (FWHT) is proposed for security enhancement. In this technique, bits of plain image is randomized by shuffling the bits randomly. The obtained scrambled image is then masked with FZP using symmetric encryption in FWHT domain to obtain final encrypted image. FWHT has been used in the cryptosystem so as to protect image data from the quantization error and for reconstructing the image perfectly. The FZP used in proposed scheme increases the key space and makes it robust to many traditional attacks. The effectiveness and robustness of the proposed cryptosystem has been analyzed on the basis of various parameters by simulating on MATLAB 8.1.0 (R2012b). The experimental results are provided to highlight suitability of the proposed cryptosystem and prove that the system is secure.

Performance of the Galley Parallel File System

Science.gov (United States)

Nieuwejaar, Nils; Kotz, David

1996-01-01

As the input/output (I/O) needs of parallel scientific applications increase, file systems for multiprocessors are being designed to provide applications with parallel access to multiple disks. Many parallel file systems present applications with a conventional Unix-like interface that allows the application to access multiple disks transparently. This interface conceals the parallism within the file system, which increases the ease of programmability, but makes it difficult or impossible for sophisticated programmers and libraries to use knowledge about their I/O needs to exploit that parallelism. Furthermore, most current parallel file systems are optimized for a different workload than they are being asked to support. We introduce Galley, a new parallel file system that is intended to efficiently support realistic parallel workloads. Initial experiments, reported in this paper, indicate that Galley is capable of providing high-performance 1/O to applications the applications that rely on them. In Section 3 we describe that access data in patterns that have been observed to be common.

Image Encryption Using Stream Cipher Based on Nonlinear Combination Generator with Enhanced Security

Directory of Open Access Journals (Sweden)

Belmeguenaï Aîssa

2013-03-01

Full Text Available The images are very largely used in our daily life; the security of their transfer became necessary. In this work a novel image encryption scheme using stream cipher algorithm based on nonlinear combination generator is developed. The main contribution of this work is to enhance the security of encrypted image. The proposed scheme is based on the use the several linear feedback shifts registers whose feedback polynomials are primitive and of degrees are all pairwise coprimes combined by resilient function whose resiliency order, algebraic degree and nonlinearity attain Siegenthaler’s and Sarkar, al.’s bounds. This proposed scheme is simple and highly efficient. In order to evaluate performance, the proposed algorithm was measured through a series of tests. These tests included visual test and histogram analysis, key space analysis, correlation coefficient analysis, image entropy, key sensitivity analysis, noise analysis, Berlekamp-Massey attack, correlation attack and algebraic attack. Experimental results demonstrate the proposed system is highly key sensitive, highly resistance to the noises and shows a good resistance against brute-force, statistical attacks, Berlekamp-Massey attack, correlation attack, algebraic attack and a robust system which makes it a potential candidate for encryption of image.

Obfuscatable multi-recipient re-encryption for secure privacy-preserving personal health record services.

Science.gov (United States)

Shi, Yang; Fan, Hongfei; Xiong, Guoyue

2015-01-01

With the rapid development of cloud computing techniques, it is attractive for personal health record (PHR) service providers to deploy their PHR applications and store the personal health data in the cloud. However, there could be a serious privacy leakage if the cloud-based system is intruded by attackers, which makes it necessary for the PHR service provider to encrypt all patients' health data on cloud servers. Existing techniques are insufficiently secure under circumstances where advanced threats are considered, or being inefficient when many recipients are involved. Therefore, the objectives of our solution are (1) providing a secure implementation of re-encryption in white-box attack contexts and (2) assuring the efficiency of the implementation even in multi-recipient cases. We designed the multi-recipient re-encryption functionality by randomness-reusing and protecting the implementation by obfuscation. The proposed solution is secure even in white-box attack contexts. Furthermore, a comparison with other related work shows that the computational cost of the proposed solution is lower. The proposed technique can serve as a building block for supporting secure, efficient and privacy-preserving personal health record service systems.

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 ...

RAMA: A file system for massively parallel computers

Science.gov (United States)

Miller, Ethan L.; Katz, Randy H.

1993-01-01

This paper describes a file system design for massively parallel computers which makes very efficient use of a few disks per processor. This overcomes the traditional I/O bottleneck of massively parallel machines by storing the data on disks within the high-speed interconnection network. In addition, the file system, called RAMA, requires little inter-node synchronization, removing another common bottleneck in parallel processor file systems. Support for a large tertiary storage system can easily be integrated in lo the file system; in fact, RAMA runs most efficiently when tertiary storage is used.

Privacy Preserving Similarity Based Text Retrieval through Blind Storage

Directory of Open Access Journals (Sweden)

Pinki Kumari

2016-09-01

Full Text Available Cloud computing is improving rapidly due to their more advantage and more data owners give interest to outsource their data into cloud storage for centralize their data. As huge files stored in the cloud storage, there is need to implement the keyword based search process to data user. At the same time to protect the privacy of data, encryption techniques are used for sensitive data, that encryption is done before outsourcing data to cloud server. But it is critical to search results in encryption data. In this system we propose similarity text retrieval from the blind storage blocks with encryption format. This system provides more security because of blind storage system. In blind storage system data is stored randomly on cloud storage.  In Existing Data Owner cannot encrypt the document data as it was done only at server end. Everyone can access the data as there was no private key concept applied to maintained privacy of the data. But In our proposed system, Data Owner can encrypt the data himself using RSA algorithm.  RSA is a public key-cryptosystem and it is widely used for sensitive data storage over Internet. In our system we use Text mining process for identifying the index files of user documents. Before encryption we also use NLP (Nature Language Processing technique to identify the keyword synonyms of data owner document. Here text mining process examines text word by word and collect literal meaning beyond the words group that composes the sentence. Those words are examined in API of word net so that only equivalent words can be identified for index file use. Our proposed system provides more secure and authorized way of recover the text in cloud storage with access control. Finally, our experimental result shows that our system is better than existing.

Compression-RSA technique: A more efficient encryption-decryption procedure

Science.gov (United States)

Mandangan, Arif; Mei, Loh Chai; Hung, Chang Ee; Che Hussin, Che Haziqah

2014-06-01

The efficiency of encryption-decryption procedures has become a major problem in asymmetric cryptography. Compression-RSA technique is developed to overcome the efficiency problem by compressing the numbers of kplaintext, where k∈Z+ and k > 2, becoming only 2 plaintext. That means, no matter how large the numbers of plaintext, they will be compressed to only 2 plaintext. The encryption-decryption procedures are expected to be more efficient since these procedures only receive 2 inputs to be processed instead of kinputs. However, it is observed that as the numbers of original plaintext are increasing, the size of the new plaintext becomes bigger. As a consequence, it will probably affect the efficiency of encryption-decryption procedures, especially for RSA cryptosystem since both of its encryption-decryption procedures involve exponential operations. In this paper, we evaluated the relationship between the numbers of original plaintext and the size of the new plaintext. In addition, we conducted several experiments to show that the RSA cryptosystem with embedded Compression-RSA technique is more efficient than the ordinary RSA cryptosystem.

Key Generation for Fast Inversion of the Paillier Encryption Function

Science.gov (United States)

Hirano, Takato; Tanaka, Keisuke

We study fast inversion of the Paillier encryption function. Especially, we focus only on key generation, and do not modify the Paillier encryption function. We propose three key generation algorithms based on the speeding-up techniques for the RSA encryption function. By using our algorithms, the size of the private CRT exponent is half of that of Paillier-CRT. The first algorithm employs the extended Euclidean algorithm. The second algorithm employs factoring algorithms, and can construct the private CRT exponent with low Hamming weight. The third algorithm is a variant of the second one, and has some advantage such as compression of the private CRT exponent and no requirement for factoring algorithms. We also propose the settings of the parameters for these algorithms and analyze the security of the Paillier encryption function by these algorithms against known attacks. Finally, we give experimental results of our algorithms.

Optical image encryption scheme with multiple light paths based on compressive ghost imaging

Science.gov (United States)

Zhu, Jinan; Yang, Xiulun; Meng, Xiangfeng; Wang, Yurong; Yin, Yongkai; Sun, Xiaowen; Dong, Guoyan

2018-02-01

An optical image encryption method with multiple light paths is proposed based on compressive ghost imaging. In the encryption process, M random phase-only masks (POMs) are generated by means of logistic map algorithm, and these masks are then uploaded to the spatial light modulator (SLM). The collimated laser light is divided into several beams by beam splitters as it passes through the SLM, and the light beams illuminate the secret images, which are converted into sparse images by discrete wavelet transform beforehand. Thus, the secret images are simultaneously encrypted into intensity vectors by ghost imaging. The distances between the SLM and secret images vary and can be used as the main keys with original POM and the logistic map algorithm coefficient in the decryption process. In the proposed method, the storage space can be significantly decreased and the security of the system can be improved. The feasibility, security and robustness of the method are further analysed through computer simulations.

Query-Biased Preview over Outsourced and Encrypted Data

Science.gov (United States)

Luo, Guangchun; Qin, Ke; Chen, Aiguo

2013-01-01

For both convenience and security, more and more users encrypt their sensitive data before outsourcing it to a third party such as cloud storage service. However, searching for the desired documents becomes problematic since it is costly to download and decrypt each possibly needed 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. PMID:24078798

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.

Query-biased preview over outsourced and encrypted data.

Science.gov (United States)

Peng, Ningduo; Luo, Guangchun; Qin, Ke; Chen, Aiguo

2013-01-01

For both convenience and security, more and more users encrypt their sensitive data before outsourcing it to a third party such as cloud storage service. However, searching for the desired documents becomes problematic since it is costly to download and decrypt each possibly needed 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.

Specifying a Realistic File System

Directory of Open Access Journals (Sweden)

Sidney Amani

2015-11-01

Full Text Available We present the most interesting elements of the correctness specification of BilbyFs, a performant Linux flash file system. The BilbyFs specification supports asynchronous writes, a feature that has been overlooked by several file system verification projects, and has been used to verify the correctness of BilbyFs's fsync( C implementation. It makes use of nondeterminism to be concise and is shallowly-embedded in higher-order logic.

Research on key technologies for data-interoperability-based metadata, data compression and encryption, and their application

Science.gov (United States)

Yu, Xu; Shao, Quanqin; Zhu, Yunhai; Deng, Yuejin; Yang, Haijun

2006-10-01

With the development of informationization and the separation between data management departments and application departments, spatial data sharing becomes one of the most important objectives for the spatial information infrastructure construction, and spatial metadata management system, data transmission security and data compression are the key technologies to realize spatial data sharing. This paper discusses the key technologies for metadata based on data interoperability, deeply researches the data compression algorithms such as adaptive Huffman algorithm, LZ77 and LZ78 algorithm, studies to apply digital signature technique to encrypt spatial data, which can not only identify the transmitter of spatial data, but also find timely whether the spatial data are sophisticated during the course of network transmission, and based on the analysis of symmetric encryption algorithms including 3DES,AES and asymmetric encryption algorithm - RAS, combining with HASH algorithm, presents a improved mix encryption method for spatial data. Digital signature technology and digital watermarking technology are also discussed. Then, a new solution of spatial data network distribution is put forward, which adopts three-layer architecture. Based on the framework, we give a spatial data network distribution system, which is efficient and safe, and also prove the feasibility and validity of the proposed solution.

Encrypted data stream identification using randomness sparse representation and fuzzy Gaussian mixture model

Science.gov (United States)

Zhang, Hong; Hou, Rui; Yi, Lei; Meng, Juan; Pan, Zhisong; Zhou, Yuhuan

2016-07-01

The accurate identification of encrypted data stream helps to regulate illegal data, detect network attacks and protect users' information. In this paper, a novel encrypted data stream identification algorithm is introduced. The proposed method is based on randomness characteristics of encrypted data stream. We use a l1-norm regularized logistic regression to improve sparse representation of randomness features and Fuzzy Gaussian Mixture Model (FGMM) to improve identification accuracy. Experimental results demonstrate that the method can be adopted as an effective technique for encrypted data stream identification.

Adding Data Management Services to Parallel File Systems

Energy Technology Data Exchange (ETDEWEB)

Brandt, Scott [Univ. of California, Santa Cruz, CA (United States)

2015-03-04

The objective of this project, called DAMASC for “Data Management in Scientific Computing”, is to coalesce data management with parallel file system management to present a declarative interface to scientists for managing, querying, and analyzing extremely large data sets efficiently and predictably. Managing extremely large data sets is a key challenge of exascale computing. The overhead, energy, and cost of moving massive volumes of data demand designs where computation is close to storage. In current architectures, compute/analysis clusters access data in a physically separate parallel file system and largely leave it scientist to reduce data movement. Over the past decades the high-end computing community has adopted middleware with multiple layers of abstractions and specialized file formats such as NetCDF-4 and HDF5. These abstractions provide a limited set of high-level data processing functions, but have inherent functionality and performance limitations: middleware that provides access to the highly structured contents of scientific data files stored in the (unstructured) file systems can only optimize to the extent that file system interfaces permit; the highly structured formats of these files often impedes native file system performance optimizations. We are developing Damasc, an enhanced high-performance file system with native rich data management services. Damasc will enable efficient queries and updates over files stored in their native byte-stream format while retaining the inherent performance of file system data storage via declarative queries and updates over views of underlying files. Damasc has four key benefits for the development of data-intensive scientific code: (1) applications can use important data-management services, such as declarative queries, views, and provenance tracking, that are currently available only within database systems; (2) the use of these services becomes easier, as they are provided within a familiar file

Clockwise: A Mixed-Media File System

NARCIS (Netherlands)

Bosch, H.G.P.; Jansen, P.G.; Mullender, Sape J.

This (short) paper presents the Clockwise, a mixed-media file system. The primary goal of the Clockwise is to provide a storage architecture that supports the storage and retrieval of best-effort and real-time file system data. Clockwise provides an abstraction called a dynamic partition that groups

Homomorphic encryption-based secure SIFT for privacy-preserving feature extraction

Science.gov (United States)

Hsu, Chao-Yung; Lu, Chun-Shien; Pei, Soo-Chang

2011-02-01

Privacy has received much attention but is still largely ignored in the multimedia community. Consider a cloud computing scenario, where the server is resource-abundant and is capable of finishing the designated tasks, it is envisioned that secure media retrieval and search with privacy-preserving will be seriously treated. In view of the fact that scale-invariant feature transform (SIFT) has been widely adopted in various fields, this paper is the first to address the problem of secure SIFT feature extraction and representation in the encrypted domain. Since all the operations in SIFT must be moved to the encrypted domain, we propose a homomorphic encryption-based secure SIFT method for privacy-preserving feature extraction and representation based on Paillier cryptosystem. In particular, homomorphic comparison is a must for SIFT feature detection but is still a challenging issue for homomorphic encryption methods. To conquer this problem, we investigate a quantization-like secure comparison strategy in this paper. Experimental results demonstrate that the proposed homomorphic encryption-based SIFT performs comparably to original SIFT on image benchmarks, while preserving privacy additionally. We believe that this work is an important step toward privacy-preserving multimedia retrieval in an environment, where privacy is a major concern.

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.

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.

Optimizing Input/Output Using Adaptive File System Policies

Science.gov (United States)

Madhyastha, Tara M.; Elford, Christopher L.; Reed, Daniel A.

1996-01-01

Parallel input/output characterization studies and experiments with flexible resource management algorithms indicate that adaptivity is crucial to file system performance. In this paper we propose an automatic technique for selecting and refining file system policies based on application access patterns and execution environment. An automatic classification framework allows the file system to select appropriate caching and pre-fetching policies, while performance sensors provide feedback used to tune policy parameters for specific system environments. To illustrate the potential performance improvements possible using adaptive file system policies, we present results from experiments involving classification-based and performance-based steering.

Extending Differential Fault Analysis to Dynamic S-Box Advanced Encryption Standard Implementations

Science.gov (United States)

2014-09-18

number. As a result decryption is a different function which relies on a different key to efficiently undo the work of encryption . RSA is the most...EXTENDING DIFFERENTIAL FAULT ANALYSIS TO DYNAMIC S-BOX ADVANCED ENCRYPTION STANDARD IMPLEMENTATIONS THESIS Bradley M. Flamm, Civilian AFIT-ENG-T-14-S...ADVANCED ENCRYPTION STANDARD IMPLEMENTATIONS THESIS Presented to the Faculty Department of Electrical and Computer Engineering Graduate School of

Application of the Information Encryption Technology in the Industrial Control Network Based on FPGA

Directory of Open Access Journals (Sweden)

Guo Yao-Hua

2014-07-01

Full Text Available With the rapid development of information technology industry, Information encryption is an effective means of information security. Data encryption system based on FPGA in the field of industry is elaborated in this paper, and the data acquisition module, the basic principle of 3DES algorithm, its implementation in FPGA and PMC bus interface module are introduced. Based on the function simulation, test and analysis of the design results, this scheme has the characteristics of high reliability, fast algorithm and less hardware resources, and it can be widely used in industrial networks.

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.

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

Homomorphic encryption experiments on IBM's cloud quantum computing platform

Science.gov (United States)

Huang, He-Liang; Zhao, You-Wei; Li, Tan; Li, Feng-Guang; Du, Yu-Tao; Fu, Xiang-Qun; Zhang, Shuo; Wang, Xiang; Bao, Wan-Su

2017-02-01

Quantum computing has undergone rapid development in recent years. Owing to limitations on scalability, personal quantum computers still seem slightly unrealistic in the near future. The first practical quantum computer for ordinary users is likely to be on the cloud. However, the adoption of cloud computing is possible only if security is ensured. Homomorphic encryption is a cryptographic protocol that allows computation to be performed on encrypted data without decrypting them, so it is well suited to cloud computing. Here, we first applied homomorphic encryption on IBM's cloud quantum computer platform. In our experiments, we successfully implemented a quantum algorithm for linear equations while protecting our privacy. This demonstration opens a feasible path to the next stage of development of cloud quantum information technology.

Enhancement of security using structured phase masked in optical image encryption on Fresnel transform domain

Science.gov (United States)

Yadav, Poonam Lata; Singh, Hukum

2018-05-01

To enhance the security in optical image encryption system and to protect it from the attackers, this paper proposes new digital spiral phase mask based on Fresnel Transform. In this cryptosystem the Spiral Phase Mask (SPM) used is a hybrid of Fresnel Zone Plate (FZP) and Radial Hilbert Mask (RHM) which makes the key strong and enhances the security. The different keys used for encryption and decryption purposed make the system much more secure. Proposed scheme uses various structured phase mask which increases the key space also it increases the number of parameters which makes it difficult for the attackers to exactly find the key to recover the original image. We have also used different keys for encryption and decryption purpose to make the system much more secure. The strength of the proposed cryptosystem has been analyzed by simulating on MATLAB 7.9.0(R2008a). Mean Square Errors (MSE) and Peak Signal to Noise Ratio (PSNR) are calculated for the proposed algorithm. The experimental results are provided to highlight the effectiveness and sustainability of proposed cryptosystem and to prove that the cryptosystem is secure for usage.

Double random phase spread spectrum spread space technique for secure parallel optical multiplexing with individual encryption key

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Hennelly, B. M.; Javidi, B.; Sheridan, J. T.

2005-09-01

A number of methods have been recently proposed in the literature for the encryption of 2-D information using linear optical systems. In particular the double random phase encoding system has received widespread attention. This system uses two Random Phase Keys (RPK) positioned in the input spatial domain and the spatial frequency domain and if these random phases are described by statistically independent white noises then the encrypted image can be shown to be a white noise. Decryption only requires knowledge of the RPK in the frequency domain. The RPK may be implemented using a Spatial Light Modulators (SLM). In this paper we propose and investigate the use of SLMs for secure optical multiplexing. We show that in this case it is possible to encrypt multiple images in parallel and multiplex them for transmission or storage. The signal energy is effectively spread in the spatial frequency domain. As expected the number of images that can be multiplexed together and recovered without loss is proportional to the ratio of the input image and the SLM resolution. Many more images may be multiplexed with some loss in recovery. Furthermore each individual encryption is more robust than traditional double random phase encoding since decryption requires knowledge of both RPK and a lowpass filter in order to despread the spectrum and decrypt the image. Numerical simulations are presented and discussed.

Securing Sensitive Flight and Engine Simulation Data Using Smart Card Technology

Science.gov (United States)

Blaser, Tammy M.

2003-01-01

NASA Glenn Research Center has developed a smart card prototype capable of encrypting and decrypting disk files required to run a distributed aerospace propulsion simulation. Triple Data Encryption Standard (3DES) encryption is used to secure the sensitive intellectual property on disk pre, during, and post simulation execution. The prototype operates as a secure system and maintains its authorized state by safely storing and permanently retaining the encryption keys only on the smart card. The prototype is capable of authenticating a single smart card user and includes pre simulation and post simulation tools for analysis and training purposes. The prototype's design is highly generic and can be used to protect any sensitive disk files with growth capability to urn multiple simulations. The NASA computer engineer developed the prototype on an interoperable programming environment to enable porting to other Numerical Propulsion System Simulation (NPSS) capable operating system environments.

A fast image encryption algorithm based on only blocks in cipher text

Science.gov (United States)

Wang, Xing-Yuan; Wang, Qian

2014-03-01

In this paper, a fast image encryption algorithm is proposed, in which the shuffling and diffusion is performed simultaneously. The cipher-text image is divided into blocks and each block has k ×k pixels, while the pixels of the plain-text are scanned one by one. Four logistic maps are used to generate the encryption key stream and the new place in the cipher image of plain image pixels, including the row and column of the block which the pixel belongs to and the place where the pixel would be placed in the block. After encrypting each pixel, the initial conditions of logistic maps would be changed according to the encrypted pixel's value; after encrypting each row of plain image, the initial condition would also be changed by the skew tent map. At last, it is illustrated that this algorithm has a faster speed, big key space, and better properties in withstanding differential attacks, statistical analysis, known plaintext, and chosen plaintext attacks.

A fast image encryption algorithm based on only blocks in cipher text

International Nuclear Information System (INIS)

Wang Xing-Yuan; Wang Qian

2014-01-01

In this paper, a fast image encryption algorithm is proposed, in which the shuffling and diffusion is performed simultaneously. The cipher-text image is divided into blocks and each block has k ×k pixels, while the pixels of the plain-text are scanned one by one. Four logistic maps are used to generate the encryption key stream and the new place in the cipher image of plain image pixels, including the row and column of the block which the pixel belongs to and the place where the pixel would be placed in the block. After encrypting each pixel, the initial conditions of logistic maps would be changed according to the encrypted pixel's value; after encrypting each row of plain image, the initial condition would also be changed by the skew tent map. At last, it is illustrated that this algorithm has a faster speed, big key space, and better properties in withstanding differential attacks, statistical analysis, known plaintext, and chosen plaintext attacks

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.

Verifiable Outsourced Decryption of Attribute-Based Encryption with Constant Ciphertext Length

Directory of Open Access Journals (Sweden)

Jiguo Li

2017-01-01

Full Text Available Outsourced decryption ABE system largely reduces the computation cost for users who intend to access the encrypted files stored in cloud. However, the correctness of the transformation ciphertext cannot be guaranteed because the user does not have the original ciphertext. Lai et al. provided an ABE scheme with verifiable outsourced decryption which helps the user to check whether the transformation done by the cloud is correct. In order to improve the computation performance and reduce communication overhead, we propose a new verifiable outsourcing scheme with constant ciphertext length. To be specific, our scheme achieves the following goals. (1 Our scheme is verifiable which ensures that the user efficiently checks whether the transformation is done correctly by the CSP. (2 The size of ciphertext and the number of expensive pairing operations are constant, which do not grow with the complexity of the access structure. (3 The access structure in our scheme is AND gates on multivalued attributes and we prove our scheme is verifiable and it is secure against selectively chosen-plaintext attack in the standard model. (4 We give some performance analysis which indicates that our scheme is adaptable for various limited bandwidth and computation-constrained devices, such as mobile phone.

A Simple Encryption Algorithm for Quantum Color Image

Science.gov (United States)

Li, Panchi; Zhao, Ya

2017-06-01

In this paper, a simple encryption scheme for quantum color image is proposed. Firstly, a color image is transformed into a quantum superposition state by employing NEQR (novel enhanced quantum representation), where the R,G,B values of every pixel in a 24-bit RGB true color image are represented by 24 single-qubit basic states, and each value has 8 qubits. Then, these 24 qubits are respectively transformed from a basic state into a balanced superposition state by employed the controlled rotation gates. At this time, the gray-scale values of R, G, B of every pixel are in a balanced superposition of 224 multi-qubits basic states. After measuring, the whole image is an uniform white noise, which does not provide any information. Decryption is the reverse process of encryption. The experimental results on the classical computer show that the proposed encryption scheme has better security.

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.

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.