Analysis of S-box in Image Encryption Using Root Mean Square Error Method

Science.gov (United States)

Hussain, Iqtadar; Shah, Tariq; Gondal, Muhammad Asif; Mahmood, Hasan

2012-07-01

The use of substitution boxes (S-boxes) in encryption applications has proven to be an effective nonlinear component in creating confusion and randomness. The S-box is evolving and many variants appear in literature, which include advanced encryption standard (AES) S-box, affine power affine (APA) S-box, Skipjack S-box, Gray S-box, Lui J S-box, residue prime number S-box, Xyi S-box, and S8 S-box. These S-boxes have algebraic and statistical properties which distinguish them from each other in terms of encryption strength. In some circumstances, the parameters from algebraic and statistical analysis yield results which do not provide clear evidence in distinguishing an S-box for an application to a particular set of data. In image encryption applications, the use of S-boxes needs special care because the visual analysis and perception of a viewer can sometimes identify artifacts embedded in the image. In addition to existing algebraic and statistical analysis already used for image encryption applications, we propose an application of root mean square error technique, which further elaborates the results and enables the analyst to vividly distinguish between the performances of various S-boxes. While the use of the root mean square error analysis in statistics has proven to be effective in determining the difference in original data and the processed data, its use in image encryption has shown promising results in estimating the strength of the encryption method. In this paper, we show the application of the root mean square error analysis to S-box image encryption. The parameters from this analysis are used in determining the strength of S-boxes

A light weight secure image encryption scheme based on chaos & DNA computing

Directory of Open Access Journals (Sweden)

Bhaskar Mondal

2017-10-01

Full Text Available This paper proposed a new light weight secure cryptographic scheme for secure image communication. In this scheme the plain image is permuted first using a sequence of pseudo random number (PRN and encrypted by DeoxyriboNucleic Acid (DNA computation. Two PRN sequences are generated by a Pseudo Random Number Generator (PRNG based on cross coupled chaotic logistic map using two sets of keys. The first PRN sequence is used for permuting the plain image whereas the second PRN sequence is used for generating random DNA sequence. The number of rounds of permutation and encryption may be variable to increase security. The scheme is proposed for gray label images but the scheme may be extended for color images and text data. Simulation results exhibit that the proposed scheme can defy any kind of attack.

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.

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

A fractal-based image encryption system

KAUST Repository

Abd-El-Hafiz, S. K.

2014-12-01

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

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.

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.

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

Directory of Open Access Journals (Sweden)

Ari Shawakat Tahir

2015-12-01

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

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.

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 fractal-based image encryption system

KAUST Repository

Abd-El-Hafiz, S. K.; Radwan, Ahmed Gomaa; Abdel Haleem, Sherif H.; Barakat, Mohamed L.

2014-01-01

single-fractal image and statistical analysis is performed. A general encryption system utilising multiple fractal images is, then, introduced to improve the performance and increase the encryption key up to hundreds of bits. This improvement is achieved

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

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.

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.

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)

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

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.

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.

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.

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.

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.

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)

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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

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

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 ...

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

Directory of Open Access Journals (Sweden)

Xiangjun Wu

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

Fractional Hartley transform applied to optical image encryption

Science.gov (United States)

Jimenez, C.; Torres, C.; Mattos, L.

2011-01-01

A new method for image encryption is introduced on the basis of two-dimensional (2-D) generalization of 1-D fractional Hartley transform that has been redefined recently in search of its inverse transform We encrypt the image by two fractional orders and random phase codes. It has an advantage over Hartley transform, for its fractional orders can also be used as addictional keys, and that, of course, strengthens image security. Only when all of these keys are correct, can the image be well decrypted. Computer simulations are also perfomed to confirm the possibilty of proposed method.

Fractional Hartley transform applied to optical image encryption

Energy Technology Data Exchange (ETDEWEB)

Jimenez, C [Grupo GIFES. Universidad de La Guajira. Riohacha (Colombia); Torres, C; Mattos, L, E-mail: carlosj114@gmail.com [Grupo LOI. Universidad Popular del Cesar. Valledupar (Colombia)

2011-01-01

A new method for image encryption is introduced on the basis of two-dimensional (2-D) generalization of 1-D fractional Hartley transform that has been redefined recently in search of its inverse transform We encrypt the image by two fractional orders and random phase codes. It has an advantage over Hartley transform, for its fractional orders can also be used as addictional keys, and that, of course, strengthens image security. Only when all of these keys are correct, can the image be well decrypted. Computer simulations are also perfomed to confirm the possibility of proposed method.

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.

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.

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.

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.

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.

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

Directory of Open Access Journals (Sweden)

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.

Optical image encryption with redefined fractional Hartley transform

Science.gov (United States)

Zhao, Daomu; Li, Xinxin; Chen, Linfei

2008-11-01

A new method for optical image encryption is introduced on the basis of two-dimensional (2-D) generalization of 1-D fractional Hartley transform that has been redefined recently in search of its inverse transform. We encrypt the image by two fractional orders and random phase codes. It has an advantage over Hartley transform, for its fractional orders can also be used as additional keys, and that, of course, strengthens image security. Only when all of these keys are correct, can the image be well decrypted. The optical realization is then proposed and computer simulations are also performed to confirm the possibility of the proposed method.

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

Science.gov (United States)

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

2018-01-01

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

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.

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

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.

Fourier-Mellin moment-based intertwining map for image encryption

Science.gov (United States)

Kaur, Manjit; Kumar, Vijay

2018-03-01

In this paper, a robust image encryption technique that utilizes Fourier-Mellin moments and intertwining logistic map is proposed. Fourier-Mellin moment-based intertwining logistic map has been designed to overcome the issue of low sensitivity of an input image. Multi-objective Non-Dominated Sorting Genetic Algorithm (NSGA-II) based on Reinforcement Learning (MNSGA-RL) has been used to optimize the required parameters of intertwining logistic map. Fourier-Mellin moments are used to make the secret keys more secure. Thereafter, permutation and diffusion operations are carried out on input image using secret keys. The performance of proposed image encryption technique has been evaluated on five well-known benchmark images and also compared with seven well-known existing encryption techniques. The experimental results reveal that the proposed technique outperforms others in terms of entropy, correlation analysis, a unified average changing intensity and the number of changing pixel rate. The simulation results reveal that the proposed technique provides high level of security and robustness against various types of attacks.

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

International Nuclear Information System (INIS)

Chen Guanrong; Mao Yaobin; Chui, Charles K.

2004-01-01

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

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

Science.gov (United States)

Wang, Leyuan; Song, Hongjun; Liu, Ping

2016-02-01

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

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.

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

Science.gov (United States)

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.

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

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.

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.

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

Science.gov (United States)

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.

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

Science.gov (United States)

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.

Watermarking patient data in encrypted medical images

Indian Academy of Sciences (India)

Due to the advancement of technology, internet has become an ... area including important information and must be stored without any distortion. .... Although someone with the knowledge of encryption key can obtain a decrypted image and ... ical image management, in: Engineering in Medicine and Biology Society.

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.

Chaotic Image Encryption Based on Running-Key Related to Plaintext

Directory of Open Access Journals (Sweden)

Cao Guanghui

2014-01-01

Full Text Available In the field of chaotic image encryption, the algorithm based on correlating key with plaintext has become a new developing direction. However, for this kind of algorithm, some shortcomings in resistance to reconstruction attack, efficient utilization of chaotic resource, and reducing dynamical degradation of digital chaos are found. In order to solve these problems and further enhance the security of encryption algorithm, based on disturbance and feedback mechanism, we present a new image encryption scheme. In the running-key generation stage, by successively disturbing chaotic stream with cipher-text, the relation of running-key to plaintext is established, reconstruction attack is avoided, effective use of chaotic resource is guaranteed, and dynamical degradation of digital chaos is minimized. In the image encryption stage, by introducing random-feedback mechanism, the difficulty of breaking this scheme is increased. Comparing with the-state-of-the-art algorithms, our scheme exhibits good properties such as large key space, long key period, and extreme sensitivity to the initial key and plaintext. Therefore, it can resist brute-force, reconstruction attack, and differential attack.

Chaotic image encryption based on running-key related to plaintext.

Science.gov (United States)

Guanghui, Cao; Kai, Hu; Yizhi, Zhang; Jun, Zhou; Xing, Zhang

2014-01-01

In the field of chaotic image encryption, the algorithm based on correlating key with plaintext has become a new developing direction. However, for this kind of algorithm, some shortcomings in resistance to reconstruction attack, efficient utilization of chaotic resource, and reducing dynamical degradation of digital chaos are found. In order to solve these problems and further enhance the security of encryption algorithm, based on disturbance and feedback mechanism, we present a new image encryption scheme. In the running-key generation stage, by successively disturbing chaotic stream with cipher-text, the relation of running-key to plaintext is established, reconstruction attack is avoided, effective use of chaotic resource is guaranteed, and dynamical degradation of digital chaos is minimized. In the image encryption stage, by introducing random-feedback mechanism, the difficulty of breaking this scheme is increased. Comparing with the-state-of-the-art algorithms, our scheme exhibits good properties such as large key space, long key period, and extreme sensitivity to the initial key and plaintext. Therefore, it can resist brute-force, reconstruction attack, and differential attack.

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

Directory of Open Access Journals (Sweden)

Zhaoxia Yin

2014-01-01

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

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

Science.gov (United States)

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

2018-04-01

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

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.

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.

Analysis and improvement of a chaos-based image encryption algorithm

International Nuclear Information System (INIS)

Xiao Di; Liao Xiaofeng; Wei Pengcheng

2009-01-01

The security of digital image attracts much attention recently. In Guan et al. [Guan Z, Huang F, Guan W. Chaos-based image encryption algorithm. Phys Lett A 2005; 346: 153-7.], a chaos-based image encryption algorithm has been proposed. In this paper, the cause of potential flaws in the original algorithm is analyzed in detail, and then the corresponding enhancement measures are proposed. Both theoretical analysis and computer simulation indicate that the improved algorithm can overcome these flaws and maintain all the merits of the original one.

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.

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.

An image hiding method based on cascaded iterative Fourier transform and public-key encryption algorithm

Science.gov (United States)

Zhang, B.; Sang, Jun; Alam, Mohammad S.

2013-03-01

An image hiding method based on cascaded iterative Fourier transform and public-key encryption algorithm was proposed. Firstly, the original secret image was encrypted into two phase-only masks M1 and M2 via cascaded iterative Fourier transform (CIFT) algorithm. Then, the public-key encryption algorithm RSA was adopted to encrypt M2 into M2' . Finally, a host image was enlarged by extending one pixel into 2×2 pixels and each element in M1 and M2' was multiplied with a superimposition coefficient and added to or subtracted from two different elements in the 2×2 pixels of the enlarged host image. To recover the secret image from the stego-image, the two masks were extracted from the stego-image without the original host image. By applying public-key encryption algorithm, the key distribution was facilitated, and also compared with the image hiding method based on optical interference, the proposed method may reach higher robustness by employing the characteristics of the CIFT algorithm. Computer simulations show that this method has good robustness against image processing.

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.

Optical encryption with selective computational ghost imaging

International Nuclear Information System (INIS)

Zafari, Mohammad; Kheradmand, Reza; Ahmadi-Kandjani, Sohrab

2014-01-01

Selective computational ghost imaging (SCGI) is a technique which enables the reconstruction of an N-pixel image from N measurements or less. In this paper we propose an optical encryption method based on SCGI and experimentally demonstrate that this method has much higher security under eavesdropping and unauthorized accesses compared with previous reported methods. (paper)

A Novel Image Encryption Based on Algebraic S-box and Arnold Transform

Science.gov (United States)

Farwa, Shabieh; Muhammad, Nazeer; Shah, Tariq; Ahmad, Sohail

2017-09-01

Recent study shows that substitution box (S-box) only cannot be reliably used in image encryption techniques. We, in this paper, propose a novel and secure image encryption scheme that utilizes the combined effect of an algebraic substitution box along with the scrambling effect of the Arnold transform. The underlying algorithm involves the application of S-box, which is the most imperative source to create confusion and diffusion in the data. The speciality of the proposed algorithm lies, firstly, in the high sensitivity of our S-box to the choice of the initial conditions which makes this S-box stronger than the chaos-based S-boxes as it saves computational labour by deploying a comparatively simple and direct approach based on the algebraic structure of the multiplicative cyclic group of the Galois field. Secondly the proposed method becomes more secure by considering a combination of S-box with certain number of iterations of the Arnold transform. The strength of the S-box is examined in terms of various performance indices such as nonlinearity, strict avalanche criterion, bit independence criterion, linear and differential approximation probabilities etc. We prove through the most significant techniques used for the statistical analyses of the encrypted image that our image encryption algorithm satisfies all the necessary criteria to be usefully and reliably implemented in image encryption applications.

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.

Hiding a Covert Digital Image by Assembling the RSA Encryption Method and the Binary Encoding Method

OpenAIRE

Kuang Tsan Lin; Sheng Lih Yeh

2014-01-01

The Rivest-Shamir-Adleman (RSA) encryption method and the binary encoding method are assembled to form a hybrid hiding method to hide a covert digital image into a dot-matrix holographic image. First, the RSA encryption method is used to transform the covert image to form a RSA encryption data string. Then, all the elements of the RSA encryption data string are transferred into binary data. Finally, the binary data are encoded into the dot-matrix holographic image. The pixels of the dot-matri...

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.

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)

Design of an image encryption scheme based on a multiple chaotic map

Science.gov (United States)

Tong, Xiao-Jun

2013-07-01

In order to solve the problem that chaos is degenerated in limited computer precision and Cat map is the small key space, this paper presents a chaotic map based on topological conjugacy and the chaotic characteristics are proved by Devaney definition. In order to produce a large key space, a Cat map named block Cat map is also designed for permutation process based on multiple-dimensional chaotic maps. The image encryption algorithm is based on permutation-substitution, and each key is controlled by different chaotic maps. The entropy analysis, differential analysis, weak-keys analysis, statistical analysis, cipher random analysis, and cipher sensibility analysis depending on key and plaintext are introduced to test the security of the new image encryption scheme. Through the comparison to the proposed scheme with AES, DES and Logistic encryption methods, we come to the conclusion that the image encryption method solves the problem of low precision of one dimensional chaotic function and has higher speed and higher security.

Cryptanalysis on an image block encryption algorithm based on spatiotemporal chaos

International Nuclear Information System (INIS)

Wang Xing-Yuan; He Guo-Xiang

2012-01-01

An image block encryption scheme based on spatiotemporal chaos has been proposed recently. In this paper, we analyse the security weakness of the proposal. The main problem of the original scheme is that the generated keystream remains unchanged for encrypting every image. Based on the flaws, we demonstrate a chosen plaintext attack for revealing the equivalent keys with only 6 pairs of plaintext/ciphertext used. Finally, experimental results show the validity of our attack. (general)

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

Hiding a Covert Digital Image by Assembling the RSA Encryption Method and the Binary Encoding Method

Directory of Open Access Journals (Sweden)

Kuang Tsan Lin

2014-01-01

Full Text Available The Rivest-Shamir-Adleman (RSA encryption method and the binary encoding method are assembled to form a hybrid hiding method to hide a covert digital image into a dot-matrix holographic image. First, the RSA encryption method is used to transform the covert image to form a RSA encryption data string. Then, all the elements of the RSA encryption data string are transferred into binary data. Finally, the binary data are encoded into the dot-matrix holographic image. The pixels of the dot-matrix holographic image contain seven groups of codes used for reconstructing the covert image. The seven groups of codes are identification codes, covert-image dimension codes, covert-image graylevel codes, pre-RSA bit number codes, RSA key codes, post-RSA bit number codes, and information codes. The reconstructed covert image derived from the dot-matrix holographic image and the original covert image are exactly the same.

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.

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

Science.gov (United States)

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

2017-11-01

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

Encryption and watermark-treated medical image against hacking disease-An immune convention in spatial and frequency domains.

Science.gov (United States)

Lakshmi, C; Thenmozhi, K; Rayappan, John Bosco Balaguru; Amirtharajan, Rengarajan

2018-06-01

Digital Imaging and Communications in Medicine (DICOM) is one among the significant formats used worldwide for the representation of medical images. Undoubtedly, medical-image security plays a crucial role in telemedicine applications. Merging encryption and watermarking in medical-image protection paves the way for enhancing the authentication and safer transmission over open channels. In this context, the present work on DICOM image encryption has employed a fuzzy chaotic map for encryption and the Discrete Wavelet Transform (DWT) for watermarking. The proposed approach overcomes the limitation of the Arnold transform-one of the most utilised confusion mechanisms in image ciphering. Various metrics have substantiated the effectiveness of the proposed medical-image encryption algorithm. Copyright © 2018 Elsevier B.V. All rights reserved.

Multiple-image encryption via lifting wavelet transform and XOR operation based on compressive ghost imaging scheme

Science.gov (United States)

Li, Xianye; Meng, Xiangfeng; Yang, Xiulun; Wang, Yurong; Yin, Yongkai; Peng, Xiang; He, Wenqi; Dong, Guoyan; Chen, Hongyi

2018-03-01

A multiple-image encryption method via lifting wavelet transform (LWT) and XOR operation is proposed, which is based on a row scanning compressive ghost imaging scheme. In the encryption process, the scrambling operation is implemented for the sparse images transformed by LWT, then the XOR operation is performed on the scrambled images, and the resulting XOR images are compressed in the row scanning compressive ghost imaging, through which the ciphertext images can be detected by bucket detector arrays. During decryption, the participant who possesses his/her correct key-group, can successfully reconstruct the corresponding plaintext image by measurement key regeneration, compression algorithm reconstruction, XOR operation, sparse images recovery, and inverse LWT (iLWT). Theoretical analysis and numerical simulations validate the feasibility of the proposed method.

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)

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.

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)

Digital double random amplitude image encryption method based on the symmetry property of the parametric discrete Fourier transform

Science.gov (United States)

Bekkouche, Toufik; Bouguezel, Saad

2018-03-01

We propose a real-to-real image encryption method. It is a double random amplitude encryption method based on the parametric discrete Fourier transform coupled with chaotic maps to perform the scrambling. The main idea behind this method is the introduction of a complex-to-real conversion by exploiting the inherent symmetry property of the transform in the case of real-valued sequences. This conversion allows the encrypted image to be real-valued instead of being a complex-valued image as in all existing double random phase encryption methods. The advantage is to store or transmit only one image instead of two images (real and imaginary parts). Computer simulation results and comparisons with the existing double random amplitude encryption methods are provided for peak signal-to-noise ratio, correlation coefficient, histogram analysis, and key sensitivity.

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.

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.

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.

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.

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.

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.

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.

Cryptanalysis of a chaos-based image encryption algorithm

International Nuclear Information System (INIS)

Cokal, Cahit; Solak, Ercan

2009-01-01

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

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

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.

Secure Image Steganography Algorithm Based on DCT with OTP Encryption

Directory of Open Access Journals (Sweden)

De Rosal Ignatius Moses Setiadi

2017-04-01

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

Image encryption with chaotic map and Arnold transform in the gyrator transform domains

Science.gov (United States)

Sang, Jun; Luo, Hongling; Zhao, Jun; Alam, Mohammad S.; Cai, Bin

2017-05-01

An image encryption method combing chaotic map and Arnold transform in the gyrator transform domains was proposed. Firstly, the original secret image is XOR-ed with a random binary sequence generated by a logistic map. Then, the gyrator transform is performed. Finally, the amplitude and phase of the gyrator transform are permutated by Arnold transform. The decryption procedure is the inverse operation of encryption. The secret keys used in the proposed method include the control parameter and the initial value of the logistic map, the rotation angle of the gyrator transform, and the transform number of the Arnold transform. Therefore, the key space is large, while the key data volume is small. The numerical simulation was conducted to demonstrate the effectiveness of the proposed method and the security analysis was performed in terms of the histogram of the encrypted image, the sensitiveness to the secret keys, decryption upon ciphertext loss, and resistance to the chosen-plaintext attack.

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.

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.

Devil’s Vortex Phase Structure as Frequency Plane Mask for Image Encryption Using the Fractional Mellin Transform

Directory of Open Access Journals (Sweden)

Sunanda Vashisth

2014-01-01

Full Text Available A frequency plane phase mask based on Devil’s vortex structure has been used for image encryption using the fractional Mellin transform. The phase key for decryption is obtained by an iterative phase retrieval algorithm. The proposed scheme has been validated for grayscale secret target images, by numerical simulation. The efficacy of the scheme has been evaluated by computing mean-squared-error between the secret target image and the decrypted image. Sensitivity analysis of the decryption process to variations in various encryption parameters has been carried out. The proposed encryption scheme has been seen to exhibit reasonable robustness against occlusion attack.

An Efficient Diffusion Scheme for Chaos-Based Digital Image Encryption

Directory of Open Access Journals (Sweden)

Jun-xin Chen

2014-01-01

Full Text Available In recent years, amounts of permutation-diffusion architecture-based image cryptosystems have been proposed. However, the key stream elements in the diffusion procedure are merely depending on the secret key that is usually fixed during the whole encryption process. Cryptosystems of this type suffer from unsatisfactory encryption speed and are considered insecure upon known/chosen plaintext attacks. In this paper, an efficient diffusion scheme is proposed. This scheme consists of two diffusion procedures, with a supplementary diffusion procedure padded after the normal diffusion. In the supplementary diffusion module, the control parameter of the selected chaotic map is altered by the resultant image produced after the normal diffusion operation. As a result, a slight difference in the plain image can be transferred to the chaotic iteration and bring about distinct key streams, and hence totally different cipher images will be produced. Therefore, the scheme can remarkably accelerate the diffusion effect of the cryptosystem and will effectively resist known/chosen plaintext attacks. Theoretical analyses and experimental results prove the high security performance and satisfactory operation efficiency of the proposed scheme.

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.

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

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.

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)

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.

An authenticated image encryption scheme based on chaotic maps and memory cellular automata

Science.gov (United States)

Bakhshandeh, Atieh; Eslami, Ziba

2013-06-01

This paper introduces a new image encryption scheme based on chaotic maps, cellular automata and permutation-diffusion architecture. In the permutation phase, a piecewise linear chaotic map is utilized to confuse the plain-image and in the diffusion phase, we employ the Logistic map as well as a reversible memory cellular automata to obtain an efficient and secure cryptosystem. The proposed method admits advantages such as highly secure diffusion mechanism, computational efficiency and ease of implementation. A novel property of the proposed scheme is its authentication ability which can detect whether the image is tampered during the transmission or not. This is particularly important in applications where image data or part of it contains highly sensitive information. Results of various analyses manifest high security of this new method and its capability for practical image encryption.

Fast ghost imaging and ghost encryption based on the discrete cosine transform

International Nuclear Information System (INIS)

Tanha, Mehrdad; Ahmadi-Kandjani, Sohrab; Kheradmand, Reza

2013-01-01

We introduce the discrete cosine transform as an advanced compression tool for images in computational ghost imaging. A novel approach to fast imaging and encryption, the discrete cosine transform, promotes the security level of ghost images and reduces the image retrieval time. To discuss the advantages of this technique we compare experimental outcomes with simulated ones. (paper)

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.

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.

QR code-based non-linear image encryption using Shearlet transform and spiral phase transform

Science.gov (United States)

Kumar, Ravi; Bhaduri, Basanta; Hennelly, Bryan

2018-02-01

In this paper, we propose a new quick response (QR) code-based non-linear technique for image encryption using Shearlet transform (ST) and spiral phase transform. The input image is first converted into a QR code and then scrambled using the Arnold transform. The scrambled image is then decomposed into five coefficients using the ST and the first Shearlet coefficient, C1 is interchanged with a security key before performing the inverse ST. The output after inverse ST is then modulated with a random phase mask and further spiral phase transformed to get the final encrypted image. The first coefficient, C1 is used as a private key for decryption. The sensitivity of the security keys is analysed in terms of correlation coefficient and peak signal-to noise ratio. The robustness of the scheme is also checked against various attacks such as noise, occlusion and special attacks. Numerical simulation results are shown in support of the proposed technique and an optoelectronic set-up for encryption is also proposed.

An image encryption approach based on chaotic maps

International Nuclear Information System (INIS)

Zhang Linhua; Liao Xiaofeng; Wang Xuebing

2005-01-01

It is well-known that images are different from texts in many aspects, such as highly redundancy and correlation, the local structure and the characteristics of amplitude-frequency. As a result, the methods of conventional encryption cannot be applicable to images. In this paper, we improve the properties of confusion and diffusion in terms of discrete exponential chaotic maps, and design a key scheme for the resistance to statistic attack, differential attack and grey code attack. Experimental and theoretical results also show that our scheme is efficient and very secure

Security Analysis of A Chaos-based Image Encryption Algorithm

OpenAIRE

Lian, Shiguo; Sun, Jinsheng; Wang, Zhiquan

2006-01-01

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

A novel image encryption algorithm based on chaos maps with Markov properties

Science.gov (United States)

Liu, Quan; Li, Pei-yue; Zhang, Ming-chao; Sui, Yong-xin; Yang, Huai-jiang

2015-02-01

In order to construct high complexity, secure and low cost image encryption algorithm, a class of chaos with Markov properties was researched and such algorithm was also proposed. The kind of chaos has higher complexity than the Logistic map and Tent map, which keeps the uniformity and low autocorrelation. An improved couple map lattice based on the chaos with Markov properties is also employed to cover the phase space of the chaos and enlarge the key space, which has better performance than the original one. A novel image encryption algorithm is constructed on the new couple map lattice, which is used as a key stream generator. A true random number is used to disturb the key which can dynamically change the permutation matrix and the key stream. From the experiments, it is known that the key stream can pass SP800-22 test. The novel image encryption can resist CPA and CCA attack and differential attack. The algorithm is sensitive to the initial key and can change the distribution the pixel values of the image. The correlation of the adjacent pixels can also be eliminated. When compared with the algorithm based on Logistic map, it has higher complexity and better uniformity, which is nearer to the true random number. It is also efficient to realize which showed its value in common use.

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.

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.

Underwater Image Enhancement by Adaptive Gray World and Differential Gray-Levels Histogram Equalization

Directory of Open Access Journals (Sweden)

WONG, S.-L.

2018-05-01

Full Text Available Most underwater images tend to be dominated by a single color cast. This paper presents a solution to remove the color cast and improve the contrast in underwater images. However, after the removal of the color cast using Gray World (GW method, the resultant image is not visually pleasing. Hence, we propose an integrated approach using Adaptive GW (AGW and Differential Gray-Levels Histogram Equalization (DHE that operate in parallel. The AGW is applied to remove the color cast while DHE is used to improve the contrast of the underwater image. The outputs of both chromaticity components of AGW and intensity components of DHE are combined to form the enhanced image. The results of the proposed method are compared with three existing methods using qualitative and quantitative measures. The proposed method increased the visibility of underwater images and in most cases produces better quantitative scores when compared to the three existing methods.

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.

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

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.

A Novel Image Encryption Scheme Based on Intertwining Chaotic Maps and RC4 Stream Cipher

Science.gov (United States)

Kumari, Manju; Gupta, Shailender

2018-03-01

As the systems are enabling us to transmit large chunks of data, both in the form of texts and images, there is a need to explore algorithms which can provide a higher security without increasing the time complexity significantly. This paper proposes an image encryption scheme which uses intertwining chaotic maps and RC4 stream cipher to encrypt/decrypt the images. The scheme employs chaotic map for the confusion stage and for generation of key for the RC4 cipher. The RC4 cipher uses this key to generate random sequences which are used to implement an efficient diffusion process. The algorithm is implemented in MATLAB-2016b and various performance metrics are used to evaluate its efficacy. The proposed scheme provides highly scrambled encrypted images and can resist statistical, differential and brute-force search attacks. The peak signal-to-noise ratio values are quite similar to other schemes, the entropy values are close to ideal. In addition, the scheme is very much practical since having lowest time complexity then its counterparts.

Comment on ‘A technique for image encryption using digital signature’

Science.gov (United States)

Hernández Encinas, L.; Peinado Domínguez, A.

2006-12-01

The security of a recently proposed technique for encryption images by Sinha and Singh [A. Sinha, K. Singh, Opt. Commun. 218 (2003) 229], based on the use of digital signatures and error correcting codes, is analyzed. The proposed cryptosystem is shown to have some weakness. In fact, the secret key and the original image can be recovered efficiently by a brute force attack.

Fuzzy Matching Based on Gray-scale Difference for Quantum Images

Science.gov (United States)

Luo, GaoFeng; Zhou, Ri-Gui; Liu, XingAo; Hu, WenWen; Luo, Jia

2018-05-01

Quantum image processing has recently emerged as an essential problem in practical tasks, e.g. real-time image matching. Previous studies have shown that the superposition and entanglement of quantum can greatly improve the efficiency of complex image processing. In this paper, a fuzzy quantum image matching scheme based on gray-scale difference is proposed to find out the target region in a reference image, which is very similar to the template image. Firstly, we employ the proposed enhanced quantum representation (NEQR) to store digital images. Then some certain quantum operations are used to evaluate the gray-scale difference between two quantum images by thresholding. If all of the obtained gray-scale differences are not greater than the threshold value, it indicates a successful fuzzy matching of quantum images. Theoretical analysis and experiments show that the proposed scheme performs fuzzy matching at a low cost and also enables exponentially significant speedup via quantum parallel computation.

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.

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

A proposed security technique based on watermarking and encryption for digital imaging and communications in medicine

Directory of Open Access Journals (Sweden)

Mohamed M. Abd-Eldayem

2013-03-01

Full Text Available Nowadays; modern Hospital Data Management Systems (HDMSs are applied in a computer network; in addition medicinal equipments produce medical images in a digital form. HDMS must store and exchange these images in a secured environment to provide image integrity and patient privacy. The reversible watermarking techniques can be used to provide the integrity and the privacy. In this paper, a security technique based on watermarking and encryption is proposed to be used for Digital Imaging and Communications in Medicine (DICOM. It provides patient authentication, information confidentiality and integrity based on reversible watermark. To achieve integrity service at the sender side; a hash value based on encrypted MD5 is determined from the image. And to satisfy the reversible feature; R–S-Vector is determined from the image and is compressed based on a Huffman compression algorithm. After that to provide confidentiality and authentication services: the compressed R–S-Vector, the hash value and patient ID are concatenated to form a watermark then this watermark is encrypted using AES encryption technique, finally the watermark is embedded inside the medical image. Experimental results prove that the proposed technique can provide patient authentication services, image integrity service and information confidentiality service with excellent efficiency. Concluded results for all tested DICOM medical images and natural images show the following: BER equals 0, both of SNR and PSNR are consistent and have large values, and MSE has low value; the average values of SNR, PSNR and MSE are 52 dB, 57 dB and 0.12 respectively. Therefore, watermarked images have high imperceptibility, invisibility and transparency. In addition, the watermark extracted from the image at the receiver side is identical to the watermark embedded into the image in the sender side; as a result, the proposed technique is totally reversible, and the embedded watermark does not

A NEW TECHNIQUE BASED ON CHAOTIC STEGANOGRAPHY AND ENCRYPTION TEXT IN DCT DOMAIN FOR COLOR IMAGE

Directory of Open Access Journals (Sweden)

MELAD J. SAEED

2013-10-01

Full Text Available Image steganography is the art of hiding information into a cover image. This paper presents a new technique based on chaotic steganography and encryption text in DCT domain for color image, where DCT is used to transform original image (cover image from spatial domain to frequency domain. This technique used chaotic function in two phases; firstly; for encryption secret message, second; for embedding in DCT cover image. With this new technique, good results are obtained through satisfying the important properties of steganography such as: imperceptibility; improved by having mean square error (MSE, peak signal to noise ratio (PSNR and normalized correlation (NC, to phase and capacity; improved by encoding the secret message characters with variable length codes and embedding the secret message in one level of color image only.

Application of Mean of Absolute Deviation Method for the Selection of Best Nonlinear Component Based on Video Encryption

Science.gov (United States)

Anees, Amir; Khan, Waqar Ahmad; Gondal, Muhammad Asif; Hussain, Iqtadar

2013-07-01

The aim of this work is to make use of the mean of absolute deviation (MAD) method for the evaluation process of substitution boxes used in the advanced encryption standard. In this paper, we use the MAD technique to analyze some popular and prevailing substitution boxes used in encryption processes. In particular, MAD is applied to advanced encryption standard (AES), affine power affine (APA), Gray, Lui J., Residue Prime, S8 AES, SKIPJACK, and Xyi substitution boxes.

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.

Image encryption based on permutation-substitution using chaotic map and Latin Square Image Cipher

Science.gov (United States)

Panduranga, H. T.; Naveen Kumar, S. K.; Kiran, HASH(0x22c8da0)

2014-06-01

In this paper we presented a image encryption based on permutation-substitution using chaotic map and Latin square image cipher. The proposed method consists of permutation and substitution process. In permutation process, plain image is permuted according to chaotic sequence generated using chaotic map. In substitution process, based on secrete key of 256 bit generate a Latin Square Image Cipher (LSIC) and this LSIC is used as key image and perform XOR operation between permuted image and key image. The proposed method can applied to any plain image with unequal width and height as well and also resist statistical attack, differential attack. Experiments carried out for different images of different sizes. The proposed method possesses large key space to resist brute force attack.

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.

Color Image Encryption Using Three-Dimensional Sine ICMIC Modulation Map and DNA Sequence Operations

Science.gov (United States)

Liu, Wenhao; Sun, Kehui; He, Yi; Yu, Mengyao

Derived from Sine map and iterative chaotic map with infinite collapse (ICMIC), a three-dimensional hyperchaotic Sine ICMIC modulation map (3D-SIMM) is proposed based on a close-loop modulation coupling (CMC) method. Based on this map, a novel color image encryption algorithm is designed by employing a hybrid model of multidirectional circular permutation and deoxyribonucleic acid (DNA) masking. In this scheme, the pixel positions of image are scrambled by multidirectional circular permutation, and the pixel values are substituted by DNA sequence operations. The simulation results and security analysis show that the algorithm has good encryption effect and strong key sensitivity, and can resist brute-force, statistical, differential, known-plaintext and chosen-plaintext attacks.

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

International Nuclear Information System (INIS)

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

2012-01-01

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

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.

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 Authentication with Tamper Localization and Self-Recovery in Encrypted Domain Based on Compressive Sensing

Directory of Open Access Journals (Sweden)

Rui Zhang

2018-01-01

Full Text Available This paper proposes a novel tamper detection, localization, and recovery scheme for encrypted images with Discrete Wavelet Transformation (DWT and Compressive Sensing (CS. The original image is first transformed into DWT domain and divided into important part, that is, low-frequency part, and unimportant part, that is, high-frequency part. For low-frequency part contains the main information of image, traditional chaotic encryption is employed. Then, high-frequency part is encrypted with CS to vacate space for watermark. The scheme takes the processed original image content as watermark, from which the characteristic digest values are generated. Comparing with the existing image authentication algorithms, the proposed scheme can realize not only tamper detection and localization but also tamper recovery. Moreover, tamper recovery is based on block division and the recovery accuracy varies with the contents that are possibly tampered. If either the watermark or low-frequency part is tampered, the recovery accuracy is 100%. The experimental results show that the scheme can not only distinguish the type of tamper and find the tampered blocks but also recover the main information of the original image. With great robustness and security, the scheme can adequately meet the need of secure image transmission under unreliable conditions.

A fast chaos-based image encryption scheme with a dynamic state variables selection mechanism

Science.gov (United States)

Chen, Jun-xin; Zhu, Zhi-liang; Fu, Chong; Yu, Hai; Zhang, Li-bo

2015-03-01

In recent years, a variety of chaos-based image cryptosystems have been investigated to meet the increasing demand for real-time secure image transmission. Most of them are based on permutation-diffusion architecture, in which permutation and diffusion are two independent procedures with fixed control parameters. This property results in two flaws. (1) At least two chaotic state variables are required for encrypting one plain pixel, in permutation and diffusion stages respectively. Chaotic state variables produced with high computation complexity are not sufficiently used. (2) The key stream solely depends on the secret key, and hence the cryptosystem is vulnerable against known/chosen-plaintext attacks. In this paper, a fast chaos-based image encryption scheme with a dynamic state variables selection mechanism is proposed to enhance the security and promote the efficiency of chaos-based image cryptosystems. Experimental simulations and extensive cryptanalysis have been carried out and the results prove the superior security and high efficiency of the scheme.

Optical image encryption with silhouette removal based on interference and phase blend processing

Science.gov (United States)

Wang, Qu

2012-10-01

To completely eliminate the silhouette problem that inherently exists in the earlier interference-based encryption scheme with two phase-only masks (POMs), we propose a simple new encryption method based on optical interference of one random POM and two analytically obtained POMs. Different from the previous methods which require time-consuming iterative computation or postprocessing of the POMs for silhouette removal, our method can resolve the problem during the production of the POMs based on interference principle. Information associated with the original image is smoothed away by modulation of the random POM. Illegal deciphers cannot retrieve the primitive image using only one or two of the POMs. Incorporated with the linear phase blend operation, our method can provide higher robustness against brute force attacks. Simulation results are presented to support the validity and feasibility of our method.

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.

A wavelet domain adaptive image watermarking method based on chaotic encryption

Science.gov (United States)

Wei, Fang; Liu, Jian; Cao, Hanqiang; Yang, Jun

2009-10-01

A digital watermarking technique is a specific branch of steganography, which can be used in various applications, provides a novel way to solve security problems for multimedia information. In this paper, we proposed a kind of wavelet domain adaptive image digital watermarking method using chaotic stream encrypt and human eye visual property. The secret information that can be seen as a watermarking is hidden into a host image, which can be publicly accessed, so the transportation of the secret information will not attract the attention of illegal receiver. The experimental results show that the method is invisible and robust against some image processing.

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.

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.

Encryption and display of multiple-image information using computer-generated holography with modified GS iterative algorithm

Science.gov (United States)

Xiao, Dan; Li, Xiaowei; Liu, Su-Juan; Wang, Qiong-Hua

2018-03-01

In this paper, a new scheme of multiple-image encryption and display based on computer-generated holography (CGH) and maximum length cellular automata (MLCA) is presented. With the scheme, the computer-generated hologram, which has the information of the three primitive images, is generated by modified Gerchberg-Saxton (GS) iterative algorithm using three different fractional orders in fractional Fourier domain firstly. Then the hologram is encrypted using MLCA mask. The ciphertext can be decrypted combined with the fractional orders and the rules of MLCA. Numerical simulations and experimental display results have been carried out to verify the validity and feasibility of the proposed scheme.

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.

Chaos based encryption system for encrypting electroencephalogram signals.

Science.gov (United States)

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

2014-05-01

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

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)

Differences in quantitative assessment of myocardial scar and gray zone by LGE-CMR imaging using established gray zone protocols.

Science.gov (United States)

Mesubi, Olurotimi; Ego-Osuala, Kelechi; Jeudy, Jean; Purtilo, James; Synowski, Stephen; Abutaleb, Ameer; Niekoop, Michelle; Abdulghani, Mohammed; Asoglu, Ramazan; See, Vincent; Saliaris, Anastasios; Shorofsky, Stephen; Dickfeld, Timm

2015-02-01

Late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) imaging is the gold standard for myocardial scar evaluation. Heterogeneous areas of scar ('gray zone'), may serve as arrhythmogenic substrate. Various gray zone protocols have been correlated to clinical outcomes and ventricular tachycardia channels. This study assessed the quantitative differences in gray zone and scar core sizes as defined by previously validated signal intensity (SI) threshold algorithms. High quality LGE-CMR images performed in 41 cardiomyopathy patients [ischemic (33) or non-ischemic (8)] were analyzed using previously validated SI threshold methods [Full Width at Half Maximum (FWHM), n-standard deviation (NSD) and modified-FWHM]. Myocardial scar was defined as scar core and gray zone using SI thresholds based on these methods. Scar core, gray zone and total scar sizes were then computed and compared among these models. The median gray zone mass was 2-3 times larger with FWHM (15 g, IQR: 8-26 g) compared to NSD or modified-FWHM (5 g, IQR: 3-9 g; and 8 g. IQR: 6-12 g respectively, p zone extent (percentage of total scar that was gray zone) also varied significantly among the three methods, 51 % (IQR: 42-61 %), 17 % (IQR: 11-21 %) versus 38 % (IQR: 33-43 %) for FWHM, NSD and modified-FWHM respectively (p zone and scar core. Infarct core and total myocardial scar mass also differ using these methods. Further evaluation of the most accurate quantification method is needed.

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)

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.

Hardware realization of chaos based block cipher for image encryption

KAUST Repository

Barakat, Mohamed L.; Radwan, Ahmed G.; Salama, Khaled N.

2011-01-01

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

Hardware realization of chaos based block cipher for image encryption

KAUST Repository

Barakat, Mohamed L.

2011-12-01

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

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.

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.

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.

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)....

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

Science.gov (United States)

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

2017-08-01

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

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.

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.

Quantum Hash function and its application to privacy amplification in quantum key distribution, pseudo-random number generation and image encryption

Science.gov (United States)

Yang, Yu-Guang; Xu, Peng; Yang, Rui; Zhou, Yi-Hua; Shi, Wei-Min

2016-01-01

Quantum information and quantum computation have achieved a huge success during the last years. In this paper, we investigate the capability of quantum Hash function, which can be constructed by subtly modifying quantum walks, a famous quantum computation model. It is found that quantum Hash function can act as a hash function for the privacy amplification process of quantum key distribution systems with higher security. As a byproduct, quantum Hash function can also be used for pseudo-random number generation due to its inherent chaotic dynamics. Further we discuss the application of quantum Hash function to image encryption and propose a novel image encryption algorithm. Numerical simulations and performance comparisons show that quantum Hash function is eligible for privacy amplification in quantum key distribution, pseudo-random number generation and image encryption in terms of various hash tests and randomness tests. It extends the scope of application of quantum computation and quantum information.

Quantum Hash function and its application to privacy amplification in quantum key distribution, pseudo-random number generation and image encryption

Science.gov (United States)

Yang, Yu-Guang; Xu, Peng; Yang, Rui; Zhou, Yi-Hua; Shi, Wei-Min

2016-01-01

Quantum information and quantum computation have achieved a huge success during the last years. In this paper, we investigate the capability of quantum Hash function, which can be constructed by subtly modifying quantum walks, a famous quantum computation model. It is found that quantum Hash function can act as a hash function for the privacy amplification process of quantum key distribution systems with higher security. As a byproduct, quantum Hash function can also be used for pseudo-random number generation due to its inherent chaotic dynamics. Further we discuss the application of quantum Hash function to image encryption and propose a novel image encryption algorithm. Numerical simulations and performance comparisons show that quantum Hash function is eligible for privacy amplification in quantum key distribution, pseudo-random number generation and image encryption in terms of various hash tests and randomness tests. It extends the scope of application of quantum computation and quantum information. PMID:26823196

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.

A novel image encryption algorithm based on synchronized random bit generated in cascade-coupled chaotic semiconductor ring lasers

Science.gov (United States)

Li, Jiafu; Xiang, Shuiying; Wang, Haoning; Gong, Junkai; Wen, Aijun

2018-03-01

In this paper, a novel image encryption algorithm based on synchronization of physical random bit generated in a cascade-coupled semiconductor ring lasers (CCSRL) system is proposed, and the security analysis is performed. In both transmitter and receiver parts, the CCSRL system is a master-slave configuration consisting of a master semiconductor ring laser (M-SRL) with cross-feedback and a solitary SRL (S-SRL). The proposed image encryption algorithm includes image preprocessing based on conventional chaotic maps, pixel confusion based on control matrix extracted from physical random bit, and pixel diffusion based on random bit stream extracted from physical random bit. Firstly, the preprocessing method is used to eliminate the correlation between adjacent pixels. Secondly, physical random bit with verified randomness is generated based on chaos in the CCSRL system, and is used to simultaneously generate the control matrix and random bit stream. Finally, the control matrix and random bit stream are used for the encryption algorithm in order to change the position and the values of pixels, respectively. Simulation results and security analysis demonstrate that the proposed algorithm is effective and able to resist various typical attacks, and thus is an excellent candidate for secure image communication application.

Optical image encryption based on real-valued coding and subtracting with the help of QR code

Science.gov (United States)

Deng, Xiaopeng

2015-08-01

A novel optical image encryption based on real-valued coding and subtracting is proposed with the help of quick response (QR) code. In the encryption process, the original image to be encoded is firstly transformed into the corresponding QR code, and then the corresponding QR code is encoded into two phase-only masks (POMs) by using basic vector operations. Finally, the absolute values of the real or imaginary parts of the two POMs are chosen as the ciphertexts. In decryption process, the QR code can be approximately restored by recording the intensity of the subtraction between the ciphertexts, and hence the original image can be retrieved without any quality loss by scanning the restored QR code with a smartphone. Simulation results and actual smartphone collected results show that the method is feasible and has strong tolerance to noise, phase difference and ratio between intensities of the two decryption light beams.

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.

Hand Vein Images Enhancement Based on Local Gray-level Information Histogram

Directory of Open Access Journals (Sweden)

Jun Wang

2015-06-01

Full Text Available Based on the Histogram equalization theory, this paper presents a novel concept of histogram to realize the contrast enhancement of hand vein images, avoiding the lost of topological vein structure or importing the fake vein information. Firstly, we propose the concept of gray-level information histogram, the fundamental characteristic of which is that the amplitudes of the components can objectively reflect the contribution of the gray levels and information to the representation of image information. Then, we propose the histogram equalization method that is composed of an automatic histogram separation module and an intensity transformation module, and the histogram separation module is a combination of the proposed prompt multiple threshold procedure and an optimum peak signal-to-noise (PSNR calculation to separate the histogram into small-scale detail, the use of the intensity transformation module can enhance the vein images with vein topological structure and gray information preservation for each generated sub-histogram. Experimental results show that the proposed method can achieve extremely good contrast enhancement effect.

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...

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.

A Fixed-Pattern Noise Correction Method Based on Gray Value Compensation for TDI CMOS Image Sensor.

Science.gov (United States)

Liu, Zhenwang; Xu, Jiangtao; Wang, Xinlei; Nie, Kaiming; Jin, Weimin

2015-09-16

In order to eliminate the fixed-pattern noise (FPN) in the output image of time-delay-integration CMOS image sensor (TDI-CIS), a FPN correction method based on gray value compensation is proposed. One hundred images are first captured under uniform illumination. Then, row FPN (RFPN) and column FPN (CFPN) are estimated based on the row-mean vector and column-mean vector of all collected images, respectively. Finally, RFPN are corrected by adding the estimated RFPN gray value to the original gray values of pixels in the corresponding row, and CFPN are corrected by subtracting the estimated CFPN gray value from the original gray values of pixels in the corresponding column. Experimental results based on a 128-stage TDI-CIS show that, after correcting the FPN in the image captured under uniform illumination with the proposed method, the standard-deviation of row-mean vector decreases from 5.6798 to 0.4214 LSB, and the standard-deviation of column-mean vector decreases from 15.2080 to 13.4623 LSB. Both kinds of FPN in the real images captured by TDI-CIS are eliminated effectively with the proposed method.

Hologram production and representation for corrected image

Science.gov (United States)

Jiao, Gui Chao; Zhang, Rui; Su, Xue Mei

2015-12-01

In this paper, a CCD sensor device is used to record the distorted homemade grid images which are taken by a wide angle camera. The distorted images are corrected by using methods of position calibration and correction of gray with vc++ 6.0 and opencv software. Holography graphes for the corrected pictures are produced. The clearly reproduced images are obtained where Fresnel algorithm is used in graph processing by reducing the object and reference light from Fresnel diffraction to delete zero-order part of the reproduced images. The investigation is useful in optical information processing and image encryption transmission.

System for Information Encryption Implementing Several Chaotic Orbits

Directory of Open Access Journals (Sweden)

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

An enhanced chaotic key-based RC5 block cipher adapted to image encryption

Science.gov (United States)

Faragallah, Osama S.

2012-07-01

RC5 is a block cipher that has several salient features such as adaptability to process different word lengths with a variable block size, a variable number of rounds and a variable-length secret key. However, RC5 can be broken with various attacks such as correlation attack, timing attack, known plaintext correlation attack and differential attacks, revealing weak security. We aimed to enhance the RC5 block cipher to be more secure and efficient for real-time applications while preserving its advantages. For this purpose, this article introduces a new approach based on strengthening both the confusion and diffusion operations by combining chaos and cryptographic primitive operations to produce round keys with better pseudo-random sequences. Comparative security analysis and performance evaluation of the enhanced RC5 block cipher (ERC5) with RC5, RC6 and chaotic block cipher algorithm (CBCA) are addressed. Several test images are used for inspecting the validity of the encryption and decryption algorithms. The experimental results show the superiority of the suggested enhanced RC5 (ERC5) block cipher to image encryption algorithms such as RC5, RC6 and CBCA from the security analysis and performance evaluation points of view.

A fast image encryption algorithm based on chaotic map

Science.gov (United States)

Liu, Wenhao; Sun, Kehui; Zhu, Congxu

2016-09-01

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

Image Encryption Technology Based on Fractional Two-Dimensional Triangle Function Combination Discrete Chaotic Map Coupled with Menezes-Vanstone Elliptic Curve Cryptosystem

Directory of Open Access Journals (Sweden)

Zeyu Liu

2018-01-01

Full Text Available A new fractional two-dimensional triangle function combination discrete chaotic map (2D-TFCDM with the discrete fractional difference is proposed. We observe the bifurcation behaviors and draw the bifurcation diagrams, the largest Lyapunov exponent plot, and the phase portraits of the proposed map, respectively. On the application side, we apply the proposed discrete fractional map into image encryption with the secret keys ciphered by Menezes-Vanstone Elliptic Curve Cryptosystem (MVECC. Finally, the image encryption algorithm is analysed in four main aspects that indicate the proposed algorithm is better than others.

Local gray level S-curve transformation - A generalized contrast enhancement technique for medical images.

Science.gov (United States)

Gandhamal, Akash; Talbar, Sanjay; Gajre, Suhas; Hani, Ahmad Fadzil M; Kumar, Dileep

2017-04-01

Most medical images suffer from inadequate contrast and brightness, which leads to blurred or weak edges (low contrast) between adjacent tissues resulting in poor segmentation and errors in classification of tissues. Thus, contrast enhancement to improve visual information is extremely important in the development of computational approaches for obtaining quantitative measurements from medical images. In this research, a contrast enhancement algorithm that applies gray-level S-curve transformation technique locally in medical images obtained from various modalities is investigated. The S-curve transformation is an extended gray level transformation technique that results into a curve similar to a sigmoid function through a pixel to pixel transformation. This curve essentially increases the difference between minimum and maximum gray values and the image gradient, locally thereby, strengthening edges between adjacent tissues. The performance of the proposed technique is determined by measuring several parameters namely, edge content (improvement in image gradient), enhancement measure (degree of contrast enhancement), absolute mean brightness error (luminance distortion caused by the enhancement), and feature similarity index measure (preservation of the original image features). Based on medical image datasets comprising 1937 images from various modalities such as ultrasound, mammograms, fluorescent images, fundus, X-ray radiographs and MR images, it is found that the local gray-level S-curve transformation outperforms existing techniques in terms of improved contrast and brightness, resulting in clear and strong edges between adjacent tissues. The proposed technique can be used as a preprocessing tool for effective segmentation and classification of tissue structures in medical images. Copyright © 2017 Elsevier Ltd. All rights reserved.

Cryptanalysis and improvement of an optical image encryption scheme using a chaotic Baker map and double random phase encoding

International Nuclear Information System (INIS)

Chen, Jun-Xin; Fu, Chong; Zhu, Zhi-Liang; Zhang, Li-Bo; Zhang, Yushu

2014-01-01

In this paper, we evaluate the security of an enhanced double random phase encoding (DRPE) image encryption scheme (2013 J. Lightwave Technol. 31 2533). The original system employs a chaotic Baker map prior to DRPE to provide more protection to the plain image and hence promote the security level of DRPE, as claimed. However, cryptanalysis shows that this scheme is vulnerable to a chosen-plaintext attack, and the ciphertext can be precisely recovered. The corresponding improvement is subsequently reported upon the basic premise that no extra equipment or computational complexity is required. The simulation results and security analyses prove its effectiveness and security. The proposed achievements are suitable for all cryptosystems under permutation and, following that, the DRPE architecture, and we hope that our work can motivate the further research on optical image encryption. (paper)

Cryptanalysis and improvement of an optical image encryption scheme using a chaotic Baker map and double random phase encoding

Science.gov (United States)

Chen, Jun-Xin; Zhu, Zhi-Liang; Fu, Chong; Zhang, Li-Bo; Zhang, Yushu

2014-12-01

In this paper, we evaluate the security of an enhanced double random phase encoding (DRPE) image encryption scheme (2013 J. Lightwave Technol. 31 2533). The original system employs a chaotic Baker map prior to DRPE to provide more protection to the plain image and hence promote the security level of DRPE, as claimed. However, cryptanalysis shows that this scheme is vulnerable to a chosen-plaintext attack, and the ciphertext can be precisely recovered. The corresponding improvement is subsequently reported upon the basic premise that no extra equipment or computational complexity is required. The simulation results and security analyses prove its effectiveness and security. The proposed achievements are suitable for all cryptosystems under permutation and, following that, the DRPE architecture, and we hope that our work can motivate the further research on optical image encryption.

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.

Encryption of QR code and grayscale image in interference-based scheme with high quality retrieval and silhouette problem removal

Science.gov (United States)

Qin, Yi; Wang, Hongjuan; Wang, Zhipeng; Gong, Qiong; Wang, Danchen

2016-09-01

In optical interference-based encryption (IBE) scheme, the currently available methods have to employ the iterative algorithms in order to encrypt two images and retrieve cross-talk free decrypted images. In this paper, we shall show that this goal can be achieved via an analytical process if one of the two images is QR code. For decryption, the QR code is decrypted in the conventional architecture and the decryption has a noisy appearance. Nevertheless, the robustness of QR code against noise enables the accurate acquisition of its content from the noisy retrieval, as a result of which the primary QR code can be exactly regenerated. Thereafter, a novel optical architecture is proposed to recover the grayscale image by aid of the QR code. In addition, the proposal has totally eliminated the silhouette problem existing in the previous IBE schemes, and its effectiveness and feasibility have been demonstrated by numerical simulations.

Hardware stream cipher with controllable chaos generator for colour image encryption

KAUST Repository

Barakat, Mohamed L.

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 the bias from the original chaotic sequence. The proposed stream cipher utilises the processed chaotic output to mask and diffuse input pixels through several stages of XORing and bit permutations. The performance of the cipher is tested with several input images and compared with previously reported systems showing superior security and higher hardware efficiency. The system is experimentally verified on XilinxVirtex 4 field programmable gate array (FPGA) achieving small area utilisation and a throughput of 3.62 Gb/s. © The Institution of Engineering and Technology 2013.

Image feature extraction in encrypted domain with privacy-preserving SIFT.

Science.gov (United States)

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

2012-11-01

Privacy has received considerable 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 applications with privacy preservation will be treated seriously. In view of the fact that scale-invariant feature transform (SIFT) has been widely adopted in various fields, this paper is the first to target the importance of privacy-preserving SIFT (PPSIFT) and to address the problem of secure SIFT feature extraction and representation in the encrypted domain. As all of the operations in SIFT must be moved to the encrypted domain, we propose a privacy-preserving realization of the SIFT method based on homomorphic encryption. We show through the security analysis based on the discrete logarithm problem and RSA that PPSIFT is secure against ciphertext only attack and known plaintext attack. Experimental results obtained from different case studies demonstrate that the proposed homomorphic encryption-based privacy-preserving SIFT performs comparably to the original SIFT and that our method is useful in SIFT-based privacy-preserving applications.

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

Science.gov (United States)

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.

Impulsive Synchronization of Reaction-Diffusion Neural Networks With Mixed Delays and Its Application to Image Encryption.

Science.gov (United States)

Chen, Wu-Hua; Luo, Shixian; Zheng, Wei Xing

2016-12-01

This paper presents a new impulsive synchronization criterion of two identical reaction-diffusion neural networks with discrete and unbounded distributed delays. The new criterion is established by applying an impulse-time-dependent Lyapunov functional combined with the use of a new type of integral inequality for treating the reaction-diffusion terms. The impulse-time-dependent feature of the proposed Lyapunov functional can capture more hybrid dynamical behaviors of the impulsive reaction-diffusion neural networks than the conventional impulse-time-independent Lyapunov functions/functionals, while the new integral inequality, which is derived from Wirtinger's inequality, overcomes the conservatism introduced by the integral inequality used in the previous results. Numerical examples demonstrate the effectiveness of the proposed method. Later, the developed impulsive synchronization method is applied to build a spatiotemporal chaotic cryptosystem that can transmit an encrypted image. The experimental results verify that the proposed image-encrypting cryptosystem has the advantages of large key space and high security against some traditional attacks.

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

A novel image encryption algorithm using chaos and reversible cellular automata

Science.gov (United States)

Wang, Xingyuan; Luan, Dapeng

2013-11-01

In this paper, a novel image encryption scheme is proposed based on reversible cellular automata (RCA) combining chaos. In this algorithm, an intertwining logistic map with complex behavior and periodic boundary reversible cellular automata are used. We split each pixel of image into units of 4 bits, then adopt pseudorandom key stream generated by the intertwining logistic map to permute these units in confusion stage. And in diffusion stage, two-dimensional reversible cellular automata which are discrete dynamical systems are applied to iterate many rounds to achieve diffusion on bit-level, in which we only consider the higher 4 bits in a pixel because the higher 4 bits carry almost the information of an image. Theoretical analysis and experimental results demonstrate the proposed algorithm achieves a high security level and processes good performance against common attacks like differential attack and statistical attack. This algorithm belongs to the class of symmetric systems.

Combination of Sharing Matrix and Image Encryption for Lossless $(k,n)$ -Secret Image Sharing.

Science.gov (United States)

Bao, Long; Yi, Shuang; Zhou, Yicong

2017-12-01

This paper first introduces a (k,n) -sharing matrix S (k, n) and its generation algorithm. Mathematical analysis is provided to show its potential for secret image sharing. Combining sharing matrix with image encryption, we further propose a lossless (k,n) -secret image sharing scheme (SMIE-SIS). Only with no less than k shares, all the ciphertext information and security key can be reconstructed, which results in a lossless recovery of original information. This can be proved by the correctness and security analysis. Performance evaluation and security analysis demonstrate that the proposed SMIE-SIS with arbitrary settings of k and n has at least five advantages: 1) it is able to fully recover the original image without any distortion; 2) it has much lower pixel expansion than many existing methods; 3) its computation cost is much lower than the polynomial-based secret image sharing methods; 4) it is able to verify and detect a fake share; and 5) even using the same original image with the same initial settings of parameters, every execution of SMIE-SIS is able to generate completely different secret shares that are unpredictable and non-repetitive. This property offers SMIE-SIS a high level of security to withstand many different attacks.

3D shape recovery from image focus using gray level co-occurrence matrix

Science.gov (United States)

Mahmood, Fahad; Munir, Umair; Mehmood, Fahad; Iqbal, Javaid

2018-04-01

Recovering a precise and accurate 3-D shape of the target object utilizing robust 3-D shape recovery algorithm is an ultimate objective of computer vision community. Focus measure algorithm plays an important role in this architecture which convert the color values of each pixel of the acquired 2-D image dataset into corresponding focus values. After convolving the focus measure filter with the input 2-D image dataset, a 3-D shape recovery approach is applied which will recover the depth map. In this document, we are concerned with proposing Gray Level Co-occurrence Matrix along with its statistical features for computing the focus information of the image dataset. The Gray Level Co-occurrence Matrix quantifies the texture present in the image using statistical features and then applies joint probability distributive function of the gray level pairs of the input image. Finally, we quantify the focus value of the input image using Gaussian Mixture Model. Due to its little computational complexity, sharp focus measure curve, robust to random noise sources and accuracy, it is considered as superior alternative to most of recently proposed 3-D shape recovery approaches. This algorithm is deeply investigated on real image sequences and synthetic image dataset. The efficiency of the proposed scheme is also compared with the state of art 3-D shape recovery approaches. Finally, by means of two global statistical measures, root mean square error and correlation, we claim that this approach -in spite of simplicity generates accurate results.

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

Directory of Open Access Journals (Sweden)

Filipp B. Burtyka

2017-06-01

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

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.

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)

LSB-based Steganography Using Reflected Gray Code for Color Quantum Images

Science.gov (United States)

Li, Panchi; Lu, Aiping

2018-02-01

At present, the classical least-significant-bit (LSB) based image steganography has been extended to quantum image processing. For the existing LSB-based quantum image steganography schemes, the embedding capacity is no more than 3 bits per pixel. Therefore, it is meaningful to study how to improve the embedding capacity of quantum image steganography. This work presents a novel LSB-based steganography using reflected Gray code for colored quantum images, and the embedding capacity of this scheme is up to 4 bits per pixel. In proposed scheme, the secret qubit sequence is considered as a sequence of 4-bit segments. For the four bits in each segment, the first bit is embedded in the second LSB of B channel of the cover image, and and the remaining three bits are embedded in LSB of RGB channels of each color pixel simultaneously using reflected-Gray code to determine the embedded bit from secret information. Following the transforming rule, the LSB of stego-image are not always same as the secret bits and the differences are up to almost 50%. Experimental results confirm that the proposed scheme shows good performance and outperforms the previous ones currently found in the literature in terms of embedding capacity.

A joint image encryption and watermarking algorithm based on compressive sensing and chaotic map

International Nuclear Information System (INIS)

Xiao Di; Cai Hong-Kun; Zheng Hong-Ying

2015-01-01

In this paper, a compressive sensing (CS) and chaotic map-based joint image encryption and watermarking algorithm is proposed. The transform domain coefficients of the original image are scrambled by Arnold map firstly. Then the watermark is adhered to the scrambled data. By compressive sensing, a set of watermarked measurements is obtained as the watermarked cipher image. In this algorithm, watermark embedding and data compression can be performed without knowing the original image; similarly, watermark extraction will not interfere with decryption. Due to the characteristics of CS, this algorithm features compressible cipher image size, flexible watermark capacity, and lossless watermark extraction from the compressed cipher image as well as robustness against packet loss. Simulation results and analyses show that the algorithm achieves good performance in the sense of security, watermark capacity, extraction accuracy, reconstruction, robustness, etc. (paper)

Nonlinear QR code based optical image encryption using spiral phase transform, equal modulus decomposition and singular value decomposition

Science.gov (United States)

Kumar, Ravi; Bhaduri, Basanta; Nishchal, Naveen K.

2018-01-01

In this study, we propose a quick response (QR) code based nonlinear optical image encryption technique using spiral phase transform (SPT), equal modulus decomposition (EMD) and singular value decomposition (SVD). First, the primary image is converted into a QR code and then multiplied with a spiral phase mask (SPM). Next, the product is spiral phase transformed with particular spiral phase function, and further, the EMD is performed on the output of SPT, which results into two complex images, Z 1 and Z 2. Among these, Z 1 is further Fresnel propagated with distance d, and Z 2 is reserved as a decryption key. Afterwards, SVD is performed on Fresnel propagated output to get three decomposed matrices i.e. one diagonal matrix and two unitary matrices. The two unitary matrices are modulated with two different SPMs and then, the inverse SVD is performed using the diagonal matrix and modulated unitary matrices to get the final encrypted image. Numerical simulation results confirm the validity and effectiveness of the proposed technique. The proposed technique is robust against noise attack, specific attack, and brutal force attack. Simulation results are presented in support of the proposed idea.

Single-beam image encryption using spatially separated ciphertexts based on interference principle in the Fresnel domain

Science.gov (United States)

Wang, Qu; Guo, Qing; Lei, Liang; Zhou, Jinyun

2014-12-01

A new optical security system for image encryption based on optical interference principle and translation property of Fresnel transform (FrT) has been proposed in this article. The algorithm of this proposal is specially designed for single-beam optical decryption and can thoroughly resolve the silhouette problem existing in the previous interference-based scheme. Different from earlier schemes using interference of phase-only masks (POMs), the inverse FrT of primitive image is digitally decomposed into a random POM and a complex field distribution. Information associated with the primitive images can be completely smoothed away by the modulation of this random POM. Through the translation property of FrT, two linear phase-only terms are then used to modulate the obtained random POM and the complex distribution, respectively. Two complex ciphertexts are generated by performing digital inverse FrT again. One cannot recover any visible information of secret image using only one ciphertext. Moreover, to recover the primitive image correctly, the correct ciphertexts must be placed in the certain positions of input plane of decryption system, respectively. As additional keys, position center coordinates of ciphertexts can increase the security strength of this encryption system against brute force attacks greatly. Numerical simulations have been given to verify the performance and feasibility of this proposal. To further enhance the application value of this algorithm, an alternative approach based on Fourier transform has also been discussed briefly.

Improved Encrypted-Signals-Based Reversible Data Hiding Using Code Division Multiplexing and Value Expansion

Directory of Open Access Journals (Sweden)

Xianyi Chen

2018-01-01

Full Text Available Compared to the encrypted-image-based reversible data hiding (EIRDH method, the encrypted-signals-based reversible data hiding (ESRDH technique is a novel way to achieve a greater embedding rate and better quality of the decrypted signals. Motivated by ESRDH using signal energy transfer, we propose an improved ESRDH method using code division multiplexing and value expansion. At the beginning, each pixel of the original image is divided into several parts containing a little signal and multiple equal signals. Next, all signals are encrypted by Paillier encryption. And then a large number of secret bits are embedded into the encrypted signals using code division multiplexing and value expansion. Since the sum of elements in any spreading sequence is equal to 0, lossless quality of directly decrypted signals can be achieved using code division multiplexing on the encrypted equal signals. Although the visual quality is reduced, high-capacity data hiding can be accomplished by conducting value expansion on the encrypted little signal. The experimental results show that our method is better than other methods in terms of the embedding rate and average PSNR.

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

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

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)

Contrast Enhancement Method Based on Gray and Its Distance Double-Weighting Histogram Equalization for 3D CT Images of PCBs

Directory of Open Access Journals (Sweden)

Lei Zeng

2016-01-01

Full Text Available Cone beam computed tomography (CBCT is a new detection method for 3D nondestructive testing of printed circuit boards (PCBs. However, the obtained 3D image of PCBs exhibits low contrast because of several factors, such as the occurrence of metal artifacts and beam hardening, during the process of CBCT imaging. Histogram equalization (HE algorithms cannot effectively extend the gray difference between a substrate and a metal in 3D CT images of PCBs, and the reinforcing effects are insignificant. To address this shortcoming, this study proposes an image enhancement algorithm based on gray and its distance double-weighting HE. Considering the characteristics of 3D CT images of PCBs, the proposed algorithm uses gray and its distance double-weighting strategy to change the form of the original image histogram distribution, suppresses the grayscale of a nonmetallic substrate, and expands the grayscale of wires and other metals. The proposed algorithm also enhances the gray difference between a substrate and a metal and highlights metallic materials. The proposed algorithm can enhance the gray value of wires and other metals in 3D CT images of PCBs. It applies enhancement strategies of changing gray and its distance double-weighting mechanism to adapt to this particular purpose. The flexibility and advantages of the proposed algorithm are confirmed by analyses and experimental results.

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....

MR imaging of heterotopic gray matter

International Nuclear Information System (INIS)

Kryst-Widzgowska, T.; Kozlowski, P.; Poniatowska, R.

1994-01-01

Six patients with heterotopic gray matter were evaluated with MR. 5 patients had history of seizures. 4 cases were suspected of the cerebral tumor. In the MR examination areas of heterotopic gray matter were found along the posterior horn of the lateral ventricle on the one side in 4 cases and bilateraly in 2 cases. In 3 cases another brain abnormalities were also detected including: hypoplasia of corpus callosum, hypoplasia of brain hemisphere, cavum septi pellucidi. MR is a modality of choice in the assessment of abnormal gray matter migration. (author)

Generalized double-humped logistic map-based medical image encryption

Directory of Open Access Journals (Sweden)

Samar M. Ismail

2018-03-01

Full Text Available This paper presents the design of the generalized Double Humped (DH logistic map, used for pseudo-random number key generation (PRNG. The generalized parameter added to the map provides more control on the map chaotic range. A new special map with a zooming effect of the bifurcation diagram is obtained by manipulating the generalization parameter value. The dynamic behavior of the generalized map is analyzed, including the study of the fixed points and stability ranges, Lyapunov exponent, and the complete bifurcation diagram. The option of designing any specific map is made possible through changing the general parameter increasing the randomness and controllability of the map. An image encryption algorithm is introduced based on pseudo-random sequence generation using the proposed generalized DH map offering secure communication transfer of medical MRI and X-ray images. Security analyses are carried out to consolidate system efficiency including: key sensitivity and key-space analyses, histogram analysis, correlation coefficients, MAE, NPCR and UACI calculations. System robustness against noise attacks has been proved along with the NIST test ensuring the system efficiency. A comparison between the proposed system with respect to previous works is presented.

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.

A new feedback image encryption scheme based on perturbation with dynamical compound chaotic sequence cipher generator

Science.gov (United States)

Tong, Xiaojun; Cui, Minggen; Wang, Zhu

2009-07-01

The design of the new compound two-dimensional chaotic function is presented by exploiting two one-dimensional chaotic functions which switch randomly, and the design is used as a chaotic sequence generator which is proved by Devaney's definition proof of chaos. The properties of compound chaotic functions are also proved rigorously. In order to improve the robustness against difference cryptanalysis and produce avalanche effect, a new feedback image encryption scheme is proposed using the new compound chaos by selecting one of the two one-dimensional chaotic functions randomly and a new image pixels method of permutation and substitution is designed in detail by array row and column random controlling based on the compound chaos. The results from entropy analysis, difference analysis, statistical analysis, sequence randomness analysis, cipher sensitivity analysis depending on key and plaintext have proven that the compound chaotic sequence cipher can resist cryptanalytic, statistical and brute-force attacks, and especially it accelerates encryption speed, and achieves higher level of security. By the dynamical compound chaos and perturbation technology, the paper solves the problem of computer low precision of one-dimensional chaotic function.

A chaos-based digital image encryption scheme with an improved diffusion strategy.

Science.gov (United States)

Fu, Chong; Chen, Jun-jie; Zou, Hao; Meng, Wei-hong; Zhan, Yong-feng; Yu, Ya-wen

2012-01-30

Chaos-based image cipher has been widely investigated over the last decade or so to meet the increasing demand for real-time secure image transmission over public networks. In this paper, an improved diffusion strategy is proposed to promote the efficiency of the most widely investigated permutation-diffusion type image cipher. By using the novel bidirectional diffusion strategy, the spreading process is significantly accelerated and hence the same level of security can be achieved with fewer overall encryption rounds. Moreover, to further enhance the security of the cryptosystem, a plain-text related chaotic orbit turbulence mechanism is introduced in diffusion procedure by perturbing the control parameter of the employed chaotic system according to the cipher-pixel. Extensive cryptanalysis has been performed on the proposed scheme using differential analysis, key space analysis, various statistical analyses and key sensitivity analysis. Results of our analyses indicate that the new scheme has a satisfactory security level with a low computational complexity, which renders it a good candidate for real-time secure image transmission applications.

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)

Diffusion-tensor MR imaging of gray and white matter development during normal human brain maturation.

Science.gov (United States)

Mukherjee, Pratik; Miller, Jeffrey H; Shimony, Joshua S; Philip, Joseph V; Nehra, Deepika; Snyder, Abraham Z; Conturo, Thomas E; Neil, Jeffrey J; McKinstry, Robert C

2002-10-01

Conventional MR imaging findings of human brain development are thought to result from decreasing water content, increasing macromolecular concentration, and myelination. We use diffusion-tensor MR imaging to test theoretical models that incorporate hypotheses regarding how these maturational processes influence water diffusion in developing gray and white matter. Experimental data were derived from diffusion-tensor imaging of 167 participants, ages 31 gestational weeks to 11 postnatal years. An isotropic diffusion model was applied to the gray matter of the basal ganglia and thalamus. A model that assumes changes in the magnitude of diffusion while maintaining cylindrically symmetric anisotropy was applied to the white matter of the corpus callosum and internal capsule. Deviations of the diffusion tensor from the ideal model predictions, due to measurement noise, were estimated by using Monte Carlo simulations. Developing gray matter of the basal ganglia and developing white matter of the internal capsule and corpus callosum largely conformed to theory, with only small departures from model predictions in older children. However, data from the thalamus substantially diverged from predicted values, with progressively larger deviations from the model with increasing participant age. Changes in water diffusion during maturation of central gray and white matter structures can largely be explained by theoretical models incorporating simple assumptions regarding the influence of brain water content and myelination, although deviations from theory increase as the brain matures. Diffusion-tensor MR imaging is a powerful method for studying the process of brain development, with both scientific and clinical applications.

Substring-Searchable Symmetric Encryption

Directory of Open Access Journals (Sweden)

Chase Melissa

2015-06-01

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

MIA - a free and open source software for gray scale medical image analysis

OpenAIRE

Wöllny, Gert; Kellman, Peter; Ledesma Carbayo, María Jesús; Skinner, Matthew M.; Hublin, Jean-Jaques; Hierl, Thomas

2013-01-01

Background Gray scale images make the bulk of data in bio-medical image analysis, and hence, the main focus of many image processing tasks lies in the processing of these monochrome images. With ever improving acquisition devices, spatial and temporal image resolution increases, and data sets become very large. Various image processing frameworks exists that make the development of new algorithms easy by using high level programming languages or visual programming. These frameworks are also a...

On the security of 3D Cat map based symmetric image encryption scheme

International Nuclear Information System (INIS)

Wang Kai; Pei, W.-J.; Zou, Liuhua; Song Aiguo; He Zhenya

2005-01-01

A 3D Cat map based symmetric image encryption algorithm, which significantly increases the resistance against statistical and differential attacks, has been proposed recently. It employs a 3D Cat map to shuffle the positions of image pixels and uses the Logistic map to diffuse the relationship between the cipher-image and the plain-image. Based on the factor that it is sufficient to break this cryptosystem only with the equivalent control parameters, some fundamental weaknesses of the cryptosystem are pointed out. With the knowledge of symbolic dynamics and some specially designed plain-images, we can calculate the equivalent initial condition of diffusion process and rebuild a valid equivalent 3D Cat matrix. In this Letter, we will propose a successful chosen-plain-text cryptanalytic attack, which is composed of two mutually independent procedures: the cryptanalysis of the diffusion process and the cryptanalysis of the spatial permutation process. Both theoretical and experimental results show that the lack of security discourages the use of these cryptosystems for practical applications

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

Science.gov (United States)

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

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

Synchronization of Markovian jumping inertial neural networks and its applications in image encryption.

Science.gov (United States)

Prakash, M; Balasubramaniam, P; Lakshmanan, S

2016-11-01

This study is mainly concerned with the problem on synchronization criteria for Markovian jumping time delayed bidirectional associative memory neural networks and their applications in secure image communications. Based on the variable transformation method, the addressed second order differential equations are transformed into first order differential equations. Then, by constructing a suitable Lyapunov-Krasovskii functional and based on integral inequalities, the criteria which ensure the synchronization between the uncontrolled system and controlled system are established through designed feedback controllers and linear matrix inequalities. Further, the proposed results proved that the error system is globally asymptotically stable in the mean square. Moreover, numerical illustrations are provided to validate the effectiveness of the derived analytical results. Finally, the application of addressed system is explored via image encryption/decryption process. Copyright © 2016 Elsevier Ltd. All rights reserved.

Optimal voxel size for measuring global gray and white matter proton metabolite concentrations using chemical shift imaging

DEFF Research Database (Denmark)

Hanson, Lars Peter Grüner; Adalsteinsson, E; Pfefferbaum, A

2000-01-01

Quantification of gray and white matter levels of spectroscopically visible metabolites can provide important insights into brain development and pathological conditions. Chemical shift imaging offers a gain in efficiency for estimation of global gray and white matter metabolite concentrations co...

Vehicle security encryption based on unlicensed encryption

Science.gov (United States)

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

2018-03-01

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

Using Chaotic System in Encryption

Science.gov (United States)

Findik, Oğuz; Kahramanli, Şirzat

In this paper chaotic systems and RSA encryption algorithm are combined in order to develop an encryption algorithm which accomplishes the modern standards. E.Lorenz's weather forecast' equations which are used to simulate non-linear systems are utilized to create chaotic map. This equation can be used to generate random numbers. In order to achieve up-to-date standards and use online and offline status, a new encryption technique that combines chaotic systems and RSA encryption algorithm has been developed. The combination of RSA algorithm and chaotic systems makes encryption system.

Spread spectrum image data hiding in the encrypted discrete cosine transform coefficients

Science.gov (United States)

Zhang, Xiaoqiang; Wang, Z. Jane

2013-10-01

Digital watermarking and data hiding are important tools for digital rights protection of media data. Spread spectrum (SS)-based watermarking and data-hiding approaches are popular due to their outstanding robustness, but their security might not be sufficient. To improve the security of SS, a SS-based image data-hiding approach is proposed by encrypting the discrete cosine transform coefficients of the host image with the piecewise linear chaotic map, before the operation of watermark embedding. To evaluate the performance of the proposed approach, simulations and analyses of its robustness and security are carried out. The average bit-error-rate values on 100 real images from the Berkeley segmentation dataset under the JPEG compression, additive Gaussian noise, salt and pepper noise, and cropping attacks are reported. Experimental results show that the proposed approach can maintain the high robustness of traditional SS schemes and, meanwhile, also improve the security. The proposed approach can extend the key space of traditional SS schemes from 10 to 10 and thus can resist brute-force attack and unauthorized detection watermark attack.

Encryption Technology based on Human Biometrics

Directory of Open Access Journals (Sweden)

Wei Yang

2017-08-01

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

Improving the Calibration of Image Sensors Based on IOFBs, Using Differential Gray-Code Space Encoding

Directory of Open Access Journals (Sweden)

Carlos Luna Vázquez

2012-07-01

Full Text Available This paper presents a fast calibration method to determine the transfer function for spatial correspondences in image transmission devices with Incoherent Optical Fiber Bundles (IOFBs, by performing a scan of the input, using differential patterns generated from a Gray code (Differential Gray-Code Space Encoding, DGSE. The results demonstrate that this technique provides a noticeable reduction in processing time and better quality of the reconstructed image compared to other, previously employed techniques, such as point or fringe scanning, or even other known space encoding techniques.

Local Directional Probability Optimization for Quantification of Blurred Gray/White Matter Junction in Magnetic Resonance Image

Directory of Open Access Journals (Sweden)

Xiaoxia Qu

2017-09-01

Full Text Available The blurred gray/white matter junction is an important feature of focal cortical dysplasia (FCD lesions. FCD is the main cause of epilepsy and can be detected through magnetic resonance (MR imaging. Several earlier studies have focused on computing the gradient magnitude of the MR image and used the resulting map to model the blurred gray/white matter junction. However, gradient magnitude cannot quantify the blurred gray/white matter junction. Therefore, we proposed a novel algorithm called local directional probability optimization (LDPO for detecting and quantifying the width of the gray/white matter boundary (GWB within the lesional areas. The proposed LDPO method mainly consists of the following three stages: (1 introduction of a hidden Markov random field-expectation-maximization algorithm to compute the probability images of brain tissues in order to obtain the GWB region; (2 generation of local directions from gray matter (GM to white matter (WM passing through the GWB, considering the GWB to be an electric potential field; (3 determination of the optimal local directions for any given voxel of GWB, based on iterative searching of the neighborhood. This was then used to measure the width of the GWB. The proposed LDPO method was tested on real MR images of patients with FCD lesions. The results indicated that the LDPO method could quantify the GWB width. On the GWB width map, the width of the blurred GWB in the lesional region was observed to be greater than that in the non-lesional regions. The proposed GWB width map produced higher F-scores in terms of detecting the blurred GWB within the FCD lesional region as compared to that of FCD feature maps, indicating better trade-off between precision and recall.

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.

Dual-Layer Video Encryption using RSA Algorithm

Science.gov (United States)

Chadha, Aman; Mallik, Sushmit; Chadha, Ankit; Johar, Ravdeep; Mani Roja, M.

2015-04-01

This paper proposes a video encryption algorithm using RSA and Pseudo Noise (PN) sequence, aimed at applications requiring sensitive video information transfers. The system is primarily designed to work with files encoded using the Audio Video Interleaved (AVI) codec, although it can be easily ported for use with Moving Picture Experts Group (MPEG) encoded files. The audio and video components of the source separately undergo two layers of encryption to ensure a reasonable level of security. Encryption of the video component involves applying the RSA algorithm followed by the PN-based encryption. Similarly, the audio component is first encrypted using PN and further subjected to encryption using the Discrete Cosine Transform. Combining these techniques, an efficient system, invulnerable to security breaches and attacks with favorable values of parameters such as encryption/decryption speed, encryption/decryption ratio and visual degradation; has been put forth. For applications requiring encryption of sensitive data wherein stringent security requirements are of prime concern, the system is found to yield negligible similarities in visual perception between the original and the encrypted video sequence. For applications wherein visual similarity is not of major concern, we limit the encryption task to a single level of encryption which is accomplished by using RSA, thereby quickening the encryption process. Although some similarity between the original and encrypted video is observed in this case, it is not enough to comprehend the happenings in the video.

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...

Bluetooth Based Chaos Synchronization Using Particle Swarm Optimization and Its Applications to Image Encryption

Directory of Open Access Journals (Sweden)

Tzu-Hsiang Hung

2012-06-01

Full Text Available This study used the complex dynamic characteristics of chaotic systems and Bluetooth to explore the topic of wireless chaotic communication secrecy and develop a communication security system. The PID controller for chaos synchronization control was applied, and the optimum parameters of this PID controller were obtained using a Particle Swarm Optimization (PSO algorithm. Bluetooth was used to realize wireless transmissions, and a chaotic wireless communication security system was developed in the design concept of a chaotic communication security system. The experimental results show that this scheme can be used successfully in image encryption.

Toward privacy-preserving JPEG image retrieval

Science.gov (United States)

Cheng, Hang; Wang, Jingyue; Wang, Meiqing; Zhong, Shangping

2017-07-01

This paper proposes a privacy-preserving retrieval scheme for JPEG images based on local variance. Three parties are involved in the scheme: the content owner, the server, and the authorized user. The content owner encrypts JPEG images for privacy protection by jointly using permutation cipher and stream cipher, and then, the encrypted versions are uploaded to the server. With an encrypted query image provided by an authorized user, the server may extract blockwise local variances in different directions without knowing the plaintext content. After that, it can calculate the similarity between the encrypted query image and each encrypted database image by a local variance-based feature comparison mechanism. The authorized user with the encryption key can decrypt the returned encrypted images with plaintext content similar to the query image. The experimental results show that the proposed scheme not only provides effective privacy-preserving retrieval service but also ensures both format compliance and file size preservation for encrypted JPEG images.

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.

Experimental color encryption in a joint transform correlator architecture

International Nuclear Information System (INIS)

Tebaldi, Myrian; Amaya, Dafne; Torroba, Roberto; Horrillo, Sergi; Perez-Cabre, Elisabet; Millan, Maria S; Bolognini, Nestor

2011-01-01

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

Secure image retrieval with multiple keys

Science.gov (United States)

Liang, Haihua; Zhang, Xinpeng; Wei, Qiuhan; Cheng, Hang

2018-03-01

This article proposes a secure image retrieval scheme under a multiuser scenario. In this scheme, the owner first encrypts and uploads images and their corresponding features to the cloud; then, the user submits the encrypted feature of the query image to the cloud; next, the cloud compares the encrypted features and returns encrypted images with similar content to the user. To find the nearest neighbor in the encrypted features, an encryption with multiple keys is proposed, in which the query feature of each user is encrypted by his/her own key. To improve the key security and space utilization, global optimization and Gaussian distribution are, respectively, employed to generate multiple keys. The experiments show that the proposed encryption can provide effective and secure image retrieval for each user and ensure confidentiality of the query feature of each user.

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.

A New Measurement Method of Iimage Encryption

International Nuclear Information System (INIS)

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

2006-01-01

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

The FBI wavelet/scalar quantization standard for gray-scale fingerprint image compression

Energy Technology Data Exchange (ETDEWEB)

Bradley, J.N.; Brislawn, C.M. [Los Alamos National Lab., NM (United States); Hopper, T. [Federal Bureau of Investigation, Washington, DC (United States)

1993-05-01

The FBI has recently adopted a standard for the compression of digitized 8-bit gray-scale fingerprint images. The standard is based on scalar quantization of a 64-subband discrete wavelet transform decomposition of the images, followed by Huffman coding. Novel features of the algorithm include the use of symmetric boundary conditions for transforming finite-length signals and a subband decomposition tailored for fingerprint images scanned at 500 dpi. The standard is intended for use in conjunction with ANSI/NBS-CLS 1-1993, American National Standard Data Format for the Interchange of Fingerprint Information, and the FBI`s Integrated Automated Fingerprint Identification System.

A Novel 1D Hybrid Chaotic Map-Based Image Compression and Encryption Using Compressed Sensing and Fibonacci-Lucas Transform

Directory of Open Access Journals (Sweden)

Tongfeng Zhang

2016-01-01

Full Text Available A one-dimensional (1D hybrid chaotic system is constructed by three different 1D chaotic maps in parallel-then-cascade fashion. The proposed chaotic map has larger key space and exhibits better uniform distribution property in some parametric range compared with existing 1D chaotic map. Meanwhile, with the combination of compressive sensing (CS and Fibonacci-Lucas transform (FLT, a novel image compression and encryption scheme is proposed with the advantages of the 1D hybrid chaotic map. The whole encryption procedure includes compression by compressed sensing (CS, scrambling with FLT, and diffusion after linear scaling. Bernoulli measurement matrix in CS is generated by the proposed 1D hybrid chaotic map due to its excellent uniform distribution. To enhance the security and complexity, transform kernel of FLT varies in each permutation round according to the generated chaotic sequences. Further, the key streams used in the diffusion process depend on the chaotic map as well as plain image, which could resist chosen plaintext attack (CPA. Experimental results and security analyses demonstrate the validity of our scheme in terms of high security and robustness against noise attack and cropping attack.

A Fingerprint Image Encryption Scheme Based on Hyperchaotic Rössler Map

Directory of Open Access Journals (Sweden)

F. Abundiz-Pérez

2016-01-01

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

A novel quantum LSB-based steganography method using the Gray code for colored quantum images

Science.gov (United States)

Heidari, Shahrokh; Farzadnia, Ehsan

2017-10-01

As one of the prevalent data-hiding techniques, steganography is defined as the act of concealing secret information in a cover multimedia encompassing text, image, video and audio, imperceptibly, in order to perform interaction between the sender and the receiver in which nobody except the receiver can figure out the secret data. In this approach a quantum LSB-based steganography method utilizing the Gray code for quantum RGB images is investigated. This method uses the Gray code to accommodate two secret qubits in 3 LSBs of each pixel simultaneously according to reference tables. Experimental consequences which are analyzed in MATLAB environment, exhibit that the present schema shows good performance and also it is more secure and applicable than the previous one currently found in the literature.

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

Science.gov (United States)

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.

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

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.

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.

[Research on K-means clustering segmentation method for MRI brain image based on selecting multi-peaks in gray histogram].

Science.gov (United States)

Chen, Zhaoxue; Yu, Haizhong; Chen, Hao

2013-12-01

To solve the problem of traditional K-means clustering in which initial clustering centers are selected randomly, we proposed a new K-means segmentation algorithm based on robustly selecting 'peaks' standing for White Matter, Gray Matter and Cerebrospinal Fluid in multi-peaks gray histogram of MRI brain image. The new algorithm takes gray value of selected histogram 'peaks' as the initial K-means clustering center and can segment the MRI brain image into three parts of tissue more effectively, accurately, steadily and successfully. Massive experiments have proved that the proposed algorithm can overcome many shortcomings caused by traditional K-means clustering method such as low efficiency, veracity, robustness and time consuming. The histogram 'peak' selecting idea of the proposed segmentootion method is of more universal availability.

Analysis on imaging features of mammography in computer radiography and investigation on gray scale transform and energy subtraction

International Nuclear Information System (INIS)

Feng Shuli

2003-01-01

In this dissertation, a novel transform method based on human visual response features for gray scale mammographic imaging in computer radiography (CR) is presented. The parameters for imaging quality on CR imaging for mammography were investigated experimentally. In addition, methods for image energy subtraction and a novel method of image registration for mammography of CR imaging are presented. Because the images are viewed and investigated by humans, the method of displaying differences in gray scale images is more convenient if the gray scale differences are displayed in a manner commensurate with human visual response principles. Through transformation of image gray scale with this method, the contrast of the image will be enhanced and the capability for humans to extract the useful information from the image will be increased. Tumors and microcalcifications are displayed in a form for humans to view more simply after transforming the image. The method is theoretically and experimentally investigated. Through measurement of the parameters of a geometrically blurred image, MTF, DQE, and ROC on CR imaging, and also comparison with the imaging quality of screen-film systems, the results indicate that CR imaging qualities in DQE and ROC are better than those of screen-film systems. In geometric blur of the image and MTF, the differences in image quality between CR and the screen-film system are very small. The results suggest that the CR system can replace the screen-film system for mammography imaging. In addition, the results show that the optimal imaging energy for CR mammography is about 24 kV. This condition indicates that the imaging energy of the CR system is lower than that of the screen-film system and, therefore, the x-ray dose to the patient for mammography with the CR system is lower than that with the screen-film system. Based on the difference of penetrability of x ray with different wavelength, and the fact that the part of the x-ray beam will pass

The FBI wavelet/scalar quantization standard for gray-scale fingerprint image compression

Energy Technology Data Exchange (ETDEWEB)

Bradley, J.N.; Brislawn, C.M. (Los Alamos National Lab., NM (United States)); Hopper, T. (Federal Bureau of Investigation, Washington, DC (United States))

1993-01-01

The FBI has recently adopted a standard for the compression of digitized 8-bit gray-scale fingerprint images. The standard is based on scalar quantization of a 64-subband discrete wavelet transform decomposition of the images, followed by Huffman coding. Novel features of the algorithm include the use of symmetric boundary conditions for transforming finite-length signals and a subband decomposition tailored for fingerprint images scanned at 500 dpi. The standard is intended for use in conjunction with ANSI/NBS-CLS 1-1993, American National Standard Data Format for the Interchange of Fingerprint Information, and the FBI's Integrated Automated Fingerprint Identification System.

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

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.

Encrypted Data Storage in EGEE

CERN Document Server

Frohner, Ákos

2006-01-01

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

Comparison of 12-bit and 8-bit gray scale resolution in MR imaging of the CNS

International Nuclear Information System (INIS)

Smith, H.J.; Bakke, S.J.; Smevik, B.; Hald, J.K.; Moen, G.; Rudenhed, B.; Abildgaard, A.

1992-01-01

A reduction in gray scale resolution of digital images from 12 to 8 bits per pixel usually means halving the storage space needed for the images. Theoretically, important diagnostic information may be lost in the process. We compared the sensitivity and specificity achieved by 4 radiologists in reading laser-printed films of original 12-bit MR images and cathode ray tube displays of the same images which had been compressed to 8 bits per pixel using a specially developed computer program. Receiver operating characteristics (ROC) curves showed no significant differences between film reading and screen reading. A paired 2-tailed t-test, applied on the data for actually positive cases, showed that the combined, average performance of the reviewers was significantly better at screen reading than at film reading. No such differences were found for actually negative cases. Some individual differences were found, but it is concluded that gray scale resolution of MR images may be reduced from 12 to 8 bits per pixel without any significant reduction in diagnostic information. (orig.)

A secure approach for encrypting and compressing biometric information employing orthogonal code and steganography

Science.gov (United States)

Islam, Muhammad F.; Islam, Mohammed N.

2012-04-01

The objective of this paper is to develop a novel approach for encryption and compression of biometric information utilizing orthogonal coding and steganography techniques. Multiple biometric signatures are encrypted individually using orthogonal codes and then multiplexed together to form a single image, which is then embedded in a cover image using the proposed steganography technique. The proposed technique employs three least significant bits for this purpose and a secret key is developed to choose one from among these bits to be replaced by the corresponding bit of the biometric image. The proposed technique offers secure transmission of multiple biometric signatures in an identification document which will be protected from unauthorized steganalysis attempt.

Searchable Encryption in Cloud Storage

OpenAIRE

Ren-Junn Hwang; Chung-Chien Lu; Jain-Shing Wu

2014-01-01

Cloud outsource storage is one of important services in cloud computing. Cloud users upload data to cloud servers to reduce the cost of managing data and maintaining hardware and software. To ensure data confidentiality, users can encrypt their files before uploading them to a cloud system. However, retrieving the target file from the encrypted files exactly is difficult for cloud server. This study proposes a protocol for performing multikeyword searches for encrypted cloud data by applying ...

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.

Computed gray levels in multislice and cone-beam computed tomography.

Science.gov (United States)

Azeredo, Fabiane; de Menezes, Luciane Macedo; Enciso, Reyes; Weissheimer, Andre; de Oliveira, Rogério Belle

2013-07-01

Gray level is the range of shades of gray in the pixels, representing the x-ray attenuation coefficient that allows for tissue density assessments in computed tomography (CT). An in-vitro study was performed to investigate the relationship between computed gray levels in 3 cone-beam CT (CBCT) scanners and 1 multislice spiral CT device using 5 software programs. Six materials (air, water, wax, acrylic, plaster, and gutta-percha) were scanned with the CBCT and CT scanners, and the computed gray levels for each material at predetermined points were measured with OsiriX Medical Imaging software (Geneva, Switzerland), OnDemand3D (CyberMed International, Seoul, Korea), E-Film (Merge Healthcare, Milwaukee, Wis), Dolphin Imaging (Dolphin Imaging & Management Solutions, Chatsworth, Calif), and InVivo Dental Software (Anatomage, San Jose, Calif). The repeatability of these measurements was calculated with intraclass correlation coefficients, and the gray levels were averaged to represent each material. Repeated analysis of variance tests were used to assess the differences in gray levels among scanners and materials. There were no differences in mean gray levels with the different software programs. There were significant differences in gray levels between scanners for each material evaluated (P <0.001). The software programs were reliable and had no influence on the CT and CBCT gray level measurements. However, the gray levels might have discrepancies when different CT and CBCT scanners are used. Therefore, caution is essential when interpreting or evaluating CBCT images because of the significant differences in gray levels between different CBCT scanners, and between CBCT and CT values. Copyright © 2013 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

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

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

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

Low gray scale values of computerized images of carotid plaques associated with increased levels of triglyceride-rich lipoproteins and with increased plaque lipid content

DEFF Research Database (Denmark)

Grønholdt, Marie-Louise M.; Nordestgaard, Børge; Weibe, Britt M.

1997-01-01

Relatioin between low gray scale values in computerized images of carotid plaques and 1) plasma levels of triglyceride-rich lipoproteins and 2) plaque lipid content......Relatioin between low gray scale values in computerized images of carotid plaques and 1) plasma levels of triglyceride-rich lipoproteins and 2) plaque lipid content...

Anti-Forensic Tool Using Double Encryption Scheme

OpenAIRE

Singh, Avtar; Singh, Kuldip

2009-01-01

In this paper we are implementing an Anti- Forensic tool that is used in data hiding approaches of the Anti-Forensic technology. This tool will encrypt a secret file twice: firstly it is encrypted with the XOR and then by the powerful AES (Advance Encryption Standard). To make XOR strong we have used three files that are selected by user. These files will create a mess with the plain text before encryption making the cipher text more secure and harder to break.

A Parallel Algorithm for Connected Component Labelling of Gray-scale Images on Homogeneous Multicore Architectures

International Nuclear Information System (INIS)

Niknam, Mehdi; Thulasiraman, Parimala; Camorlinga, Sergio

2010-01-01

Connected component labelling is an essential step in image processing. We provide a parallel version of Suzuki's sequential connected component algorithm in order to speed up the labelling process. Also, we modify the algorithm to enable labelling gray-scale images. Due to the data dependencies in the algorithm we used a method similar to pipeline to exploit parallelism. The parallel algorithm method achieved a speedup of 2.5 for image size of 256 x 256 pixels using 4 processing threads.

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

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.

Automatic adjustment of display window (gray-level condition) for MR images using neural networks

International Nuclear Information System (INIS)

Ohhashi, Akinami; Nambu, Kyojiro.

1992-01-01

We have developed a system to automatically adjust the display window width and level (WWL) for MR images using neural networks. There were three main points in the development of our system as follows: 1) We defined an index for the clarity of a displayed image, and called 'EW'. EW is a quantitative measure of the clarity of an image displayed in a certain WWL, and can be derived from the difference between gray-level with the WWL adjusted by a human expert and with a certain WWL. 2) We extracted a group of six features from a gray-level histogram of a displayed image. We designed two neural networks which are able to learn the relationship between these features and the desired output (teaching signal), 'EQ', which is normalized to 0 to 1.0 from EW. Two neural networks were used to share the patterns to be learned; one learns a variety of patterns with less accuracy, and the other learns similar patterns with accuracy. Learning was performed using a back-propagation method. As a result, the neural networks after learning are able to provide a quantitative measure, 'Q', of the clarity of images displayed in the designated WWL. 3) Using the 'Hill climbing' method, we have been able to determine the best possible WWL for a displaying image. We have tested this technique for MR brain images. The results show that this system can adjust WWL comparable to that adjusted by a human expert for the majority of test images. The neural network is effective for the automatic adjustment of the display window for MR images. We are now studying the application of this method to MR images of another regions. (author)

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

Image Steganography of Multiple File Types with Encryption and Compression Algorithms

Directory of Open Access Journals (Sweden)

Ernest Andreigh C. Centina

2017-05-01

Full Text Available The goals of this study were to develop a system intended for securing files through the technique of image steganography integrated with cryptography by utilizing ZLIB Algorithm for compressing and decompressing secret files, DES Algorithm for encryption and decryption, and Least Significant Bit Algorithm for file embedding and extraction to avoid compromise on highly confidential files from exploits of unauthorized persons. Ensuing to this, the system is in acc ordance with ISO 9126 international quality standards. Every quality criteria of the system was evaluated by 10 Information Technology professionals, and the arithmetic Mean and Standard Deviation of the survey were computed. The result exhibits that m ost of them strongly agreed that the system is excellently effective based on Functionality, Reliability, Usability, Efficiency, Maintainability and Portability conformance to ISO 9126 standards. The system was found to be a useful tool for both governmen t agencies and private institutions for it could keep not only the message secret but also the existence of that particular message or file et maintaining the privacy of highly confidential and sensitive files from unauthorized access.

Optical image security using Stokes polarimetry of spatially variant polarized beam

Science.gov (United States)

Fatima, Areeba; Nishchal, Naveen K.

2018-06-01

We propose a novel security scheme that uses vector beam characterized by the spatially variant polarization distribution. A vector beam is so generated that its helical components carry tailored phases corresponding to the image/images that is/are to be encrypted. The tailoring of phase has been done by employing the modified Gerchberg-Saxton algorithm for phase retrieval. Stokes parameters for the final vector beam is evaluated and is used to construct the ciphertext and one of the keys. The advantage of the proposed scheme is that it generates real ciphertext and keys which are easier to transmit and store than complex quantities. Moreover, the known plaintext attack is not applicable to this system. As a proof-of-concept, simulation results have been presented for securing single and double gray-scale images.

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.

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.

Image Encryption Algorithm Based on a Novel Improper Fractional-Order Attractor and a Wavelet Function Map

Directory of Open Access Journals (Sweden)

Jian-feng Zhao

2017-01-01

Full Text Available This paper presents a three-dimensional autonomous chaotic system with high fraction dimension. It is noted that the nonlinear characteristic of the improper fractional-order chaos is interesting. Based on the continuous chaos and the discrete wavelet function map, an image encryption algorithm is put forward. The key space is formed by the initial state variables, parameters, and orders of the system. Every pixel value is included in secret key, so as to improve antiattack capability of the algorithm. The obtained simulation results and extensive security analyses demonstrate the high level of security of the algorithm and show its robustness against various types of attacks.

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

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.

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.

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 ...

Determining the Number of Colors or Gray Levels in an Image Using Approximate Bayes Factors: The Pseudolikelihood Information Criterion (PLIC)

National Research Council Canada - National Science Library

Stanford, Derek C; Raftery, Adrian E

2001-01-01

.... This is motivated by medical and satellite image segmentation, and may also be useful for color and gray scale image quantization, the display and storage of computer-generated holograms, and the use...

GRAY CNVUFAC, Black-Body Radiation View Factors with Self-Shadowing

International Nuclear Information System (INIS)

Wong, R.L.

1991-01-01

Description of program or function: CNVUFAC, the General Dynamics heat-transfer radiation view program, was adapted for use on the LLNL computer system. The input and output were modified, and a node incrementing logic added for compatibility with TRUMP (NESC 771) thermal analyzer and related codes. The program performs the multiple integration necessary to evaluate the geometric black-body radiation node to node view factors. CNVUFAC uses an elemental area summation scheme to evaluate the multiple integrals. The program permits shadowing and self-shadowing. The basic configuration shapes that can be considered are cylinders, cones, spheres, ellipsoids, flat plates, disks, toroids, and polynomials of revolution. Portions of these shapes can also be considered. Card-image output containing node number and view factor information is generated for input to GRAY, a related code. GRAY performs the matrix manipulations necessary to convert black-body radiation heat-transfer view factors to gray-body view factors as required by thermal analyzer codes. The black-body view factors contain only geometric relationships. GRAY allows the effects of multiple gray-body reflections to be included. The resulting effective gray-body view factors can then be used with the corresponding fourth-power temperature differences to obtain the net radiative heat flux. GRAY accepts a matrix input or the card-image output generated by CNVUFAC. The resulting card-image GRAY output is in a form usable by TRUMP

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.

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

Science.gov (United States)

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

2017-06-01

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

Spinal Cord Gray Matter Atrophy in Amyotrophic Lateral Sclerosis.

Science.gov (United States)

Paquin, M-Ê; El Mendili, M M; Gros, C; Dupont, S M; Cohen-Adad, J; Pradat, P-F

2018-01-01

There is an emerging need for biomarkers to better categorize clinical phenotypes and predict progression in amyotrophic lateral sclerosis. This study aimed to quantify cervical spinal gray matter atrophy in amyotrophic lateral sclerosis and investigate its association with clinical disability at baseline and after 1 year. Twenty-nine patients with amyotrophic lateral sclerosis and 22 healthy controls were scanned with 3T MR imaging. Standard functional scale was recorded at the time of MR imaging and after 1 year. MR imaging data were processed automatically to measure the spinal cord, gray matter, and white matter cross-sectional areas. A statistical analysis assessed the difference in cross-sectional areas between patients with amyotrophic lateral sclerosis and controls, correlations between spinal cord and gray matter atrophy to clinical disability at baseline and at 1 year, and prediction of clinical disability at 1 year. Gray matter atrophy was more sensitive to discriminate patients with amyotrophic lateral sclerosis from controls ( P = .004) compared with spinal cord atrophy ( P = .02). Gray matter and spinal cord cross-sectional areas showed good correlations with clinical scores at baseline ( R = 0.56 for gray matter and R = 0.55 for spinal cord; P amyotrophic lateral sclerosis. © 2018 by American Journal of Neuroradiology.

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...

An Efficient Quantum Somewhat Homomorphic Symmetric Searchable Encryption

Science.gov (United States)

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.

Gray matter alterations and correlation of nutritional intake with the gray matter volume in prediabetes

Science.gov (United States)

Hou, Yi-Cheng; Lai, Chien-Han; Wu, Yu-Te; Yang, Shwu-Huey

2016-01-01

Abstract The neurophysiology of prediabetes plays an important role in preventive medicine. The dysregulation of glucose metabolism is likely linked to changes in neuron-related gray matter. Therefore, we designed this study to investigate gray matter alterations in medication-naive prediabetic patients. We expected to find alterations in the gray matter of prediabetic patients. A total of 64 prediabetic patients and 54 controls were enrolled. All subjects received T1 scans using a 3-T magnetic resonance imaging machine. Subjects also completed nutritional intake records at the 24-hour and 3-day time points to determine their carbohydrate, protein, fat, and total calorie intake. We utilized optimized voxel-based morphometry to estimate the gray matter differences between the patients and controls. In addition, the preprandial serum glucose level and the carbohydrate, protein, fat, and total calorie intake levels were tested to determine whether these parameters were correlated with the gray matter volume. Prediabetic patients had lower gray matter volumes than controls in the right anterior cingulate gyrus, right posterior cingulate gyrus, left insula, left super temporal gyrus, and left middle temporal gyrus (corrected P prediabetic patients. PMID:27336893

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.

An efficient and secure partial image encryption for wireless multimedia sensor networks using discrete wavelet transform, chaotic maps and substitution box

Science.gov (United States)

Khan, Muazzam A.; Ahmad, Jawad; Javaid, Qaisar; Saqib, Nazar A.

2017-03-01

Wireless Sensor Networks (WSN) is widely deployed in monitoring of some physical activity and/or environmental conditions. Data gathered from WSN is transmitted via network to a central location for further processing. Numerous applications of WSN can be found in smart homes, intelligent buildings, health care, energy efficient smart grids and industrial control systems. In recent years, computer scientists has focused towards findings more applications of WSN in multimedia technologies, i.e. audio, video and digital images. Due to bulky nature of multimedia data, WSN process a large volume of multimedia data which significantly increases computational complexity and hence reduces battery time. With respect to battery life constraints, image compression in addition with secure transmission over a wide ranged sensor network is an emerging and challenging task in Wireless Multimedia Sensor Networks. Due to the open nature of the Internet, transmission of data must be secure through a process known as encryption. As a result, there is an intensive demand for such schemes that is energy efficient as well as highly secure since decades. In this paper, discrete wavelet-based partial image encryption scheme using hashing algorithm, chaotic maps and Hussain's S-Box is reported. The plaintext image is compressed via discrete wavelet transform and then the image is shuffled column-wise and row wise-wise via Piece-wise Linear Chaotic Map (PWLCM) and Nonlinear Chaotic Algorithm, respectively. To get higher security, initial conditions for PWLCM are made dependent on hash function. The permuted image is bitwise XORed with random matrix generated from Intertwining Logistic map. To enhance the security further, final ciphertext is obtained after substituting all elements with Hussain's substitution box. Experimental and statistical results confirm the strength of the anticipated scheme.

Cognitive Implications of Deep Gray Matter Iron in Multiple Sclerosis.

Science.gov (United States)

Fujiwara, E; Kmech, J A; Cobzas, D; Sun, H; Seres, P; Blevins, G; Wilman, A H

2017-05-01

Deep gray matter iron accumulation is increasingly recognized in association with multiple sclerosis and can be measured in vivo with MR imaging. The cognitive implications of this pathology are not well-understood, especially vis-à-vis deep gray matter atrophy. Our aim was to investigate the relationships between cognition and deep gray matter iron in MS by using 2 MR imaging-based iron-susceptibility measures. Forty patients with multiple sclerosis (relapsing-remitting, n = 16; progressive, n = 24) and 27 healthy controls were imaged at 4.7T by using the transverse relaxation rate and quantitative susceptibility mapping. The transverse relaxation rate and quantitative susceptibility mapping values and volumes (atrophy) of the caudate, putamen, globus pallidus, and thalamus were determined by multiatlas segmentation. Cognition was assessed with the Brief Repeatable Battery of Neuropsychological Tests. Relationships between cognition and deep gray matter iron were examined by hierarchic regressions. Compared with controls, patients showed reduced memory ( P processing speed ( P = .02) and smaller putamen ( P deep gray matter iron accumulation in the current multiple sclerosis cohort. Atrophy and iron accumulation in deep gray matter both have negative but separable relationships to cognition in multiple sclerosis. © 2017 by American Journal of Neuroradiology.

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

基于计算全息的串联式三随机相位板图像加密%Image encryption technology of three random phase based on computer generated hologram

Institute of Scientific and Technical Information of China (English)

席思星; 孙欣; 刘兵; 田巍; 云茂金; 孔伟金; 张文飞; 梁键

2011-01-01

本文提出一种串联式三随机相位板图像加密的新方法，该方法充分运用计算全息记录复值光场的特性以记录加密图像，在传统的双随机相位加密系统基础上，置人第三个随机相位板在输出平面上，对输出的计算全息图进行相位调制加密，引入了新的密钥，获得很好的双密钥效果!同时由于计算全息周再现的多频特性，解密须正确提取单元频谱，进一步提高了图像传输的安全性。%A new image encryption technology of three random phase plates is proposed.Recording the encrypted image by CGH with it＇s features of Recording the value of optical field in this method,the third random phase plate was placed on the output plane in the 4f double random phase encryption system to modulate and encrypt the phase of the CGH,there are new keys,the third random phase plate,the exact drawing of the spectrum uint with the multi-frequency characteristics of CGH,which further improve the image transmission security.

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.

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.

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.

Chaotic Image Scrambling Algorithm Based on S-DES

International Nuclear Information System (INIS)

Yu, X Y; Zhang, J; Ren, H E; Xu, G S; Luo, X Y

2006-01-01

With the security requirement improvement of the image on the network, some typical image encryption methods can't meet the demands of encryption, such as Arnold cat map and Hilbert transformation. S-DES system can encrypt the input binary flow of image, but the fixed system structure and few keys will still bring some risks. However, the sensitivity of initial value that Logistic chaotic map can be well applied to the system of S-DES, which makes S-DES have larger random and key quantities. A dual image encryption algorithm based on S-DES and Logistic map is proposed. Through Matlab simulation experiments, the key quantities will attain 10 17 and the encryption speed of one image doesn't exceed one second. Compared to traditional methods, it has some merits such as easy to understand, rapid encryption speed, large keys and sensitivity to initial value

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

A Survey on Principal Aspects of Secure Image Transmission

OpenAIRE

Ali Soleymani; Zulkarnain Md Ali; Md Jan Nordin

2012-01-01

This paper is a review on the aspects and approaches of design an image cryptosystem. First a general introduction given for cryptography and images encryption and followed by different techniques in image encryption and related works for each technique surveyed. Finally, general security analysis methods for encrypted images are mentioned.

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...

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

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....

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.

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.

Encryption and decryption using FPGA

Science.gov (United States)

Nayak, Nikhilesh; Chandak, Akshay; Shah, Nisarg; Karthikeyan, B.

2017-11-01

In this paper, we are performing multiple cryptography methods on a set of data and comparing their outputs. Here AES algorithm and RSA algorithm are used. Using AES Algorithm an 8 bit input (plain text) gets encrypted using a cipher key and the result is displayed on tera term (serially). For simulation a 128 bit input is used and operated with a 128 bit cipher key to generate encrypted text. The reverse operations are then performed to get decrypted text. In RSA Algorithm file handling is used to input plain text. This text is then operated on to get the encrypted and decrypted data, which are then stored in a file. Finally the results of both the algorithms are compared.

Evaluation of Subependymal Gray Matter Heterotopias on Fetal MRI.

Science.gov (United States)

Nagaraj, U D; Peiro, J L; Bierbrauer, K S; Kline-Fath, B M

2016-04-01

Subependymal grey matter heterotopias are seen in a high proportion of children with Chiari II malformation and are potentially clinically relevant. However, despite its growing use, there is little in the literature describing its detection on fetal MRI. Our aim was to evaluate the accuracy in diagnosing subependymal gray matter heterotopias in fetuses with spinal dysraphism on fetal MR imaging. This study is a retrospective analysis of 203 fetal MRIs performed at a single institution for spinal dysraphism during a 10-year period. Corresponding obstetric sonography, postnatal imaging, and clinical/operative reports were reviewed. Of the fetal MRIs reviewed, 95 fetuses were included in our analysis; 23.2% (22/95) were suspected of having subependymal gray matter heterotopias on fetal MR imaging prospectively. However, only 50% (11/22) of these cases were confirmed on postnatal brain MR imaging. On postnatal brain MR imaging, 28.4% (27/95) demonstrated imaging findings consistent with subependymal gray matter heterotopia. Only 40.7% (11/27) of these cases were prospectively diagnosed on fetal MR imaging. Fetal MR imaging is limited in its ability to identify subependymal gray matter heterotopias in fetuses with spinal dysraphism. It is believed that this limitation relates to a combination of factors, including artifacts from fetal motion, the very small size of fetal neuroanatomy, differences in imaging techniques, and, possibly, irregularity related to denudation of the ependyma/subependyma in the presence of spinal dysraphism and/or stretching of the germinal matrix in ventriculomegaly. © 2016 by American Journal of Neuroradiology.

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...

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.

Gray Matter Concentration Abnormality in Brains of Narcolepsy Patients

Energy Technology Data Exchange (ETDEWEB)

Joo, Eun Yeon; Tae, Woo Suk; Kim, Sung Tae; Hong, Seung Bong [Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

2009-12-15

To investigate gray matter concentration changes in the brains of narcoleptic patients. Twenty-nine narcoleptic patient with cataplexy and 29 age and sex-matched normal subjects (mean age, 31 years old) underwent volumetric MRIs. The MRIs were spatially normalized to a standard T1 template and subdivided into gray matter, white matter, and cerebrospinal fluid (CSF). These segmented images were then smoothed using a 12-mm full width at half maximum (FWHM) isotropic Gaussian kernel. An optimized voxel-based morphometry protocol was used to analyze brain tissue concentrations using SPM2 (statistical parametric mapping). A one-way analysis of variance was applied to the concentration analysis of gray matter images. Narcoleptics with cataplexy showed reduced gray matter concentration in bilateral thalami, left gyrus rectus, bilateral frontopolar gyri, bilateral short insular gyri, bilateral superior frontal gyri, and right superior temporal and left inferior temporal gyri compared to normal subjects (uncorrected p < 0.001). Furthermore, small volume correction revealed gray matter concentration reduction in bilateral nuclei accumbens, hypothalami, and thalami (false discovery rate corrected p < 0.05). Gray matter concentration reductions were observed in brain regions related to excessive daytime sleepiness, cognition, attention, and memory in narcoleptics with cataplexy

Gray Matter Concentration Abnormality in Brains of Narcolepsy Patients

International Nuclear Information System (INIS)

Joo, Eun Yeon; Tae, Woo Suk; Kim, Sung Tae; Hong, Seung Bong

2009-01-01

To investigate gray matter concentration changes in the brains of narcoleptic patients. Twenty-nine narcoleptic patient with cataplexy and 29 age and sex-matched normal subjects (mean age, 31 years old) underwent volumetric MRIs. The MRIs were spatially normalized to a standard T1 template and subdivided into gray matter, white matter, and cerebrospinal fluid (CSF). These segmented images were then smoothed using a 12-mm full width at half maximum (FWHM) isotropic Gaussian kernel. An optimized voxel-based morphometry protocol was used to analyze brain tissue concentrations using SPM2 (statistical parametric mapping). A one-way analysis of variance was applied to the concentration analysis of gray matter images. Narcoleptics with cataplexy showed reduced gray matter concentration in bilateral thalami, left gyrus rectus, bilateral frontopolar gyri, bilateral short insular gyri, bilateral superior frontal gyri, and right superior temporal and left inferior temporal gyri compared to normal subjects (uncorrected p < 0.001). Furthermore, small volume correction revealed gray matter concentration reduction in bilateral nuclei accumbens, hypothalami, and thalami (false discovery rate corrected p < 0.05). Gray matter concentration reductions were observed in brain regions related to excessive daytime sleepiness, cognition, attention, and memory in narcoleptics with cataplexy

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.

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)

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.

Video Multiple Watermarking Technique Based on Image Interlacing Using DWT

Directory of Open Access Journals (Sweden)

Mohamed M. Ibrahim

2014-01-01

Full Text Available Digital watermarking is one of the important techniques to secure digital media files in the domains of data authentication and copyright protection. In the nonblind watermarking systems, the need of the original host file in the watermark recovery operation makes an overhead over the system resources, doubles memory capacity, and doubles communications bandwidth. In this paper, a robust video multiple watermarking technique is proposed to solve this problem. This technique is based on image interlacing. In this technique, three-level discrete wavelet transform (DWT is used as a watermark embedding/extracting domain, Arnold transform is used as a watermark encryption/decryption method, and different types of media (gray image, color image, and video are used as watermarks. The robustness of this technique is tested by applying different types of attacks such as: geometric, noising, format-compression, and image-processing attacks. The simulation results show the effectiveness and good performance of the proposed technique in saving system resources, memory capacity, and communications bandwidth.

Video multiple watermarking technique based on image interlacing using DWT.

Science.gov (United States)

Ibrahim, Mohamed M; Abdel Kader, Neamat S; Zorkany, M

2014-01-01

Digital watermarking is one of the important techniques to secure digital media files in the domains of data authentication and copyright protection. In the nonblind watermarking systems, the need of the original host file in the watermark recovery operation makes an overhead over the system resources, doubles memory capacity, and doubles communications bandwidth. In this paper, a robust video multiple watermarking technique is proposed to solve this problem. This technique is based on image interlacing. In this technique, three-level discrete wavelet transform (DWT) is used as a watermark embedding/extracting domain, Arnold transform is used as a watermark encryption/decryption method, and different types of media (gray image, color image, and video) are used as watermarks. The robustness of this technique is tested by applying different types of attacks such as: geometric, noising, format-compression, and image-processing attacks. The simulation results show the effectiveness and good performance of the proposed technique in saving system resources, memory capacity, and communications bandwidth.

Application of homomorphism to secure image sharing

Science.gov (United States)

Islam, Naveed; Puech, William; Hayat, Khizar; Brouzet, Robert

2011-09-01

In this paper, we present a new approach for sharing images between l players by exploiting the additive and multiplicative homomorphic properties of two well-known public key cryptosystems, i.e. RSA and Paillier. Contrary to the traditional schemes, the proposed approach employs secret sharing in a way that limits the influence of the dealer over the protocol and allows each player to participate with the help of his key-image. With the proposed approach, during the encryption step, each player encrypts his own key-image using the dealer's public key. The dealer encrypts the secret-to-be-shared image with the same public key and then, the l encrypted key-images plus the encrypted to-be shared image are multiplied homomorphically to get another encrypted image. After this step, the dealer can safely get a scrambled image which corresponds to the addition or multiplication of the l + 1 original images ( l key-images plus the secret image) because of the additive homomorphic property of the Paillier algorithm or multiplicative homomorphic property of the RSA algorithm. When the l players want to extract the secret image, they do not need to use keys and the dealer has no role. Indeed, with our approach, to extract the secret image, the l players need only to subtract their own key-image with no specific order from the scrambled image. Thus, the proposed approach provides an opportunity to use operators like multiplication on encrypted images for the development of a secure privacy preserving protocol in the image domain. We show that it is still possible to extract a visible version of the secret image with only l-1 key-images (when one key-image is missing) or when the l key-images used for the extraction are different from the l original key-images due to a lossy compression for example. Experimental results and security analysis verify and prove that the proposed approach is secure from cryptographic viewpoint.

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.

Digital color image encoding and decoding using a novel chaotic random generator

International Nuclear Information System (INIS)

Nien, H.H.; Huang, C.K.; Changchien, S.K.; Shieh, H.W.; Chen, C.T.; Tuan, Y.Y.

2007-01-01

This paper proposes a novel chaotic system, in which variables are treated as encryption keys in order to achieve secure transmission of digital color images. Since the dynamic response of chaotic system is highly sensitive to the initial values of a system and to the variation of a parameter, and chaotic trajectory is so unpredictable, we use elements of variables as encryption keys and apply these to computer internet communication of digital color images. As a result, we obtain much higher communication security. We adopt one statistic method involving correlation coefficient γ and FIPS PUB 140-1 to test on the distribution of distinguished elements of variables for continuous-time chaotic system, and accordingly select optimal encryption keys to use in secure communication of digital color images. At the transmitter end, we conduct RGB level decomposition on digital color images, and encrypt them with chaotic keys, and finally transmit them through computer internet. The same encryption keys are used to decrypt and recover the original images at the receiver end. Even if the encrypted images are stolen in the public channel, an intruder is not able to decrypt and recover the original images because of the lack of adequate encryption keys. Empirical example shows that the chaotic system and encryption keys applied in the encryption, transmission, decryption, and recovery of digital color images can achieve higher communication security and best recovered images

Gray Matter Is Targeted in First-Attack Multiple Sclerosis

Energy Technology Data Exchange (ETDEWEB)

Schutzer, Steven E.; Angel, Thomas E.; Liu, Tao; Schepmoes, Athena A.; Xie, Fang; Bergquist, Jonas P.; Vecsei, Lazlo' ; Zadori, Denes; Camp, David G.; Holland, Bart K.; Smith, Richard D.; Coyle, Patricia K.

2013-09-10

The cause of multiple sclerosis (MS), its driving pathogenesis at the earliest stages, and what factors allow the first clinical attack to manifest remain unknown. Some imaging studies suggest gray rather than white matter may be involved early, and some postulate this may be predictive of developing MS. Other imaging studies are in conflict. To determine if there was objective molecular evidence of gray matter involvement in early MS we used high-resolution mass spectrometry to identify proteins in the cerebrospinal fluid (CSF) of first-attack MS patients (two independent groups) compared to established relapsing remitting (RR) MS and controls. We found that the CSF proteins in first-attack patients were differentially enriched for gray matter components (axon, neuron, synapse). Myelin components did not distinguish these groups. The results support that gray matter dysfunction is involved early in MS, and also may be integral for the initial clinical presentation.

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

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

Hybrid cryptosystem for image file using elgamal and double playfair cipher algorithm

Science.gov (United States)

Hardi, S. M.; Tarigan, J. T.; Safrina, N.

2018-03-01

In this paper, we present an implementation of an image file encryption using hybrid cryptography. We chose ElGamal algorithm to perform asymmetric encryption and Double Playfair for the symmetric encryption. Our objective is to show that these algorithms are capable to encrypt an image file with an acceptable running time and encrypted file size while maintaining the level of security. The application was built using C# programming language and ran as a stand alone desktop application under Windows Operating System. Our test shows that the system is capable to encrypt an image with a resolution of 500×500 to a size of 976 kilobytes with an acceptable running time.

Selective encryption for H.264/AVC video coding

Science.gov (United States)

Shi, Tuo; King, Brian; Salama, Paul

2006-02-01

Due to the ease with which digital data can be manipulated and due to the ongoing advancements that have brought us closer to pervasive computing, the secure delivery of video and images has become a challenging problem. Despite the advantages and opportunities that digital video provide, illegal copying and distribution as well as plagiarism of digital audio, images, and video is still ongoing. In this paper we describe two techniques for securing H.264 coded video streams. The first technique, SEH264Algorithm1, groups the data into the following blocks of data: (1) a block that contains the sequence parameter set and the picture parameter set, (2) a block containing a compressed intra coded frame, (3) a block containing the slice header of a P slice, all the headers of the macroblock within the same P slice, and all the luma and chroma DC coefficients belonging to the all the macroblocks within the same slice, (4) a block containing all the ac coefficients, and (5) a block containing all the motion vectors. The first three are encrypted whereas the last two are not. The second method, SEH264Algorithm2, relies on the use of multiple slices per coded frame. The algorithm searches the compressed video sequence for start codes (0x000001) and then encrypts the next N bits of data.

Securing SIFT: Privacy-preserving Outsourcing Computation of Feature Extractions Over Encrypted Image Data.

Science.gov (United States)

Hu, Shengshan; Wang, Qian; Wang, Jingjun; Qin, Zhan; Ren, Kui

2016-05-13

Advances in cloud computing have greatly motivated data owners to outsource their huge amount of personal multimedia data and/or computationally expensive tasks onto the cloud by leveraging its abundant resources for cost saving and flexibility. Despite the tremendous benefits, the outsourced multimedia data and its originated applications may reveal the data owner's private information, such as the personal identity, locations or even financial profiles. This observation has recently aroused new research interest on privacy-preserving computations over outsourced multimedia data. In this paper, we propose an effective and practical privacy-preserving computation outsourcing protocol for the prevailing scale-invariant feature transform (SIFT) over massive encrypted image data. We first show that previous solutions to this problem have either efficiency/security or practicality issues, and none can well preserve the important characteristics of the original SIFT in terms of distinctiveness and robustness. We then present a new scheme design that achieves efficiency and security requirements simultaneously with the preservation of its key characteristics, by randomly splitting the original image data, designing two novel efficient protocols for secure multiplication and comparison, and carefully distributing the feature extraction computations onto two independent cloud servers. We both carefully analyze and extensively evaluate the security and effectiveness of our design. The results show that our solution is practically secure, outperforms the state-of-theart, and performs comparably to the original SIFT in terms of various characteristics, including rotation invariance, image scale invariance, robust matching across affine distortion, addition of noise and change in 3D viewpoint and illumination.

SecSIFT: Privacy-preserving Outsourcing Computation of Feature Extractions Over Encrypted Image Data.

Science.gov (United States)

Hu, Shengshan; Wang, Qian; Wang, Jingjun; Qin, Zhan; Ren, Kui

2016-05-13

Advances in cloud computing have greatly motivated data owners to outsource their huge amount of personal multimedia data and/or computationally expensive tasks onto the cloud by leveraging its abundant resources for cost saving and flexibility. Despite the tremendous benefits, the outsourced multimedia data and its originated applications may reveal the data owner's private information, such as the personal identity, locations or even financial profiles. This observation has recently aroused new research interest on privacy-preserving computations over outsourced multimedia data. In this paper, we propose an effective and practical privacy-preserving computation outsourcing protocol for the prevailing scale-invariant feature transform (SIFT) over massive encrypted image data. We first show that previous solutions to this problem have either efficiency/security or practicality issues, and none can well preserve the important characteristics of the original SIFT in terms of distinctiveness and robustness. We then present a new scheme design that achieves efficiency and security requirements simultaneously with the preservation of its key characteristics, by randomly splitting the original image data, designing two novel efficient protocols for secure multiplication and comparison, and carefully distributing the feature extraction computations onto two independent cloud servers. We both carefully analyze and extensively evaluate the security and effectiveness of our design. The results show that our solution is practically secure, outperforms the state-of-theart, and performs comparably to the original SIFT in terms of various characteristics, including rotation invariance, image scale invariance, robust matching across affine distortion, addition of noise and change in 3D viewpoint and illumination.

Novel optical scanning cryptography using Fresnel telescope imaging.

Science.gov (United States)

Yan, Aimin; Sun, Jianfeng; Hu, Zhijuan; Zhang, Jingtao; Liu, Liren

2015-07-13

We propose a new method called modified optical scanning cryptography using Fresnel telescope imaging technique for encryption and decryption of remote objects. An image or object can be optically encrypted on the fly by Fresnel telescope scanning system together with an encryption key. For image decryption, the encrypted signals are received and processed with an optical coherent heterodyne detection system. The proposed method has strong performance through use of secure Fresnel telescope scanning with orthogonal polarized beams and efficient all-optical information processing. The validity of the proposed method is demonstrated by numerical simulations and experimental results.

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.

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.

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.

The ``gray cortex``: an early sign of stress fracture

Energy Technology Data Exchange (ETDEWEB)

Mulligan, M.E. [Dept. of Radiology, Univ. of Maryland Medical Center, Baltimore, MD (United States)

1995-04-01

The purpose of this report is to describe an early radiographic sign of stress fracture, the ``gray cortex.`` The imaging findings in three patients with tibial stress fractures were reviewed. The ``gray cortex`` sign was evident on the initial conventional radiographs in all three cases. It was prospectively reported as a sign of stress fracture in two patients and was evident on the initial radiographs (taken elsewhere) of the third patient, who was referred for additional workup of a possible neoplasm. Special imaging studies (technetium-99m bone scan, computed tomography, and magnetic resonance imaging) confirmed the diagnosis in all three cases. (orig.)

The ''gray cortex'': an early sign of stress fracture

International Nuclear Information System (INIS)

Mulligan, M.E.

1995-01-01

The purpose of this report is to describe an early radiographic sign of stress fracture, the ''gray cortex.'' The imaging findings in three patients with tibial stress fractures were reviewed. The ''gray cortex'' sign was evident on the initial conventional radiographs in all three cases. It was prospectively reported as a sign of stress fracture in two patients and was evident on the initial radiographs (taken elsewhere) of the third patient, who was referred for additional workup of a possible neoplasm. Special imaging studies (technetium-99m bone scan, computed tomography, and magnetic resonance imaging) confirmed the diagnosis in all three cases. (orig.)

A Novel Image Cryptosystem Based on S-AES and Chaotic Map

Directory of Open Access Journals (Sweden)

Bai Lan

2015-01-01

Full Text Available This paper proposes a novel scheme based on simplified advanced encryption standard (S-AES for image encryption. Modified Arnold Map applied as diffusion technique for an image, and the key and dynamic S-box of encryption is generated by PWLCM. The goal is to balance rapidity and security of encryption. Experimental implementation has been done. This light encryption scheme shows resistance against chosen-plaintext attack and is suitable for sensor networks and IoT.

Robust information encryption diffractive-imaging-based scheme with special phase retrieval algorithm for a customized data container

Science.gov (United States)

Qin, Yi; Wang, Zhipeng; Wang, Hongjuan; Gong, Qiong; Zhou, Nanrun

2018-06-01

The diffractive-imaging-based encryption (DIBE) scheme has aroused wide interesting due to its compact architecture and low requirement of conditions. Nevertheless, the primary information can hardly be recovered exactly in the real applications when considering the speckle noise and potential occlusion imposed on the ciphertext. To deal with this issue, the customized data container (CDC) into DIBE is introduced and a new phase retrieval algorithm (PRA) for plaintext retrieval is proposed. The PRA, designed according to the peculiarity of the CDC, combines two key techniques from previous approaches, i.e., input-support-constraint and median-filtering. The proposed scheme can guarantee totally the reconstruction of the primary information despite heavy noise or occlusion and its effectiveness and feasibility have been demonstrated with simulation results.

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.

Cipher image damage and decisions in real time

Science.gov (United States)

Silva-García, Victor Manuel; Flores-Carapia, Rolando; Rentería-Márquez, Carlos; Luna-Benoso, Benjamín; Jiménez-Vázquez, Cesar Antonio; González-Ramírez, Marlon David

2015-01-01

This paper proposes a method for constructing permutations on m position arrangements. Our objective is to encrypt color images using advanced encryption standard (AES), using variable permutations means a different one for each 128-bit block in the first round after the x-or operation is applied. Furthermore, this research offers the possibility of knowing the original image when the encrypted figure suffered a failure from either an attack or not. This is achieved by permuting the original image pixel positions before being encrypted with AES variable permutations, which means building a pseudorandom permutation of 250,000 position arrays or more. To this end, an algorithm that defines a bijective function between the nonnegative integer and permutation sets is built. From this algorithm, the way to build permutations on the 0,1,…,m-1 array, knowing m-1 constants, is presented. The transcendental numbers are used to select these m-1 constants in a pseudorandom way. The quality of the proposed encryption according to the following criteria is evaluated: the correlation coefficient, the entropy, and the discrete Fourier transform. A goodness-of-fit test for each basic color image is proposed to measure the bits randomness degree of the encrypted figure. On the other hand, cipher images are obtained in a loss-less encryption way, i.e., no JPEG file formats are used.

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.

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.

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).

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.

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.

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.

Relationship between Hounsfield Unit in CT Scan and Gray Scale in CBCT

Directory of Open Access Journals (Sweden)

Tahmineh Razi

2014-06-01

Full Text Available Background and aims. Cone-beam computed tomography (CBCT is an imaging system which has many advantages over computed tomography (CT. In CT scan, Hounsfield Unit (HU is proportional to the degree of x-ray attenuation by the tissue. In CBCT, the degree of x-ray attenuation is shown by gray scale (voxel value. The aim of the present study was to investigate the relationship between gray scale in CBCT and Hounsfield Unit (HU in CT scan. Materials and methods. In this descriptive study, the head of a sheep was scanned with 3 CBCT and one medical CT scanner. Gray scales and HUs were detected on images. Reconstructed data were analyzed to investigate relationship between CBCT gray scales and HUs. Results. A strong correlation between gray scales of CBCT and HUs of CT scan was determined. Conclusion. Considering the fact that gray scale in CBCT is the criteria in measurement of bone density before implant treatments, it is recommended because of the lower dose and cost compared to CT scan.

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.

Clinical and Morphological Aspects of Gray Matter Heterotopia Type Developmental Malformations

International Nuclear Information System (INIS)

Zając-Mnich, Monika; Kostkiewicz, Agnieszka; Guz, Wiesław; Dziurzyńska-Białek, Ewa; Solińska, Anna; Stopa, Joanna; Kucharska-Miąsik, Iwona

2014-01-01

Gray matter heterotopia (GMH) is a malformation of the central nervous system characterized by interruption of normal neuroblasts migration between the 7 th and 16 th week of fetal development. The aim of the study was the analysis of clinical symptoms, prevalence rate and the most common concurrent central nervous system (CNS) developmental disorders as well as assessment of characteristic morphological changes of gray matter heterotopia in children hospitalized in our institution between the year 2001 and 2012. We performed a retrospective analysis of patients’ data who were hospitalized in our institution between the year 2001 and 2012. We assessed clinical data and imaging exams in children diagnosed with gray matter heterotopia confirmed in MRI (magnetic resonance imaging). GMH occurred in 26 children hospitalized in our institution between the year 2001 and 2012. Among children with gray matter heterotopia most common clinical symptoms were: epilepsy, intellectual disability and hemiparesis. The commonest location of heterotopic gray matter were fronto-parietal areas of brain parenchyma, mostly subependymal region. Gray matter heterotopia occurred with other developmental disorders of the central nervous system rather than solely and in most cases it was bilateral. Schizencephaly and abnormalities of the corpus callosum were the most often developmental disorders accompanying GMH. 1. Subependymal gray matter heterotopia was more common than subcortical GMH. Subependymal GMH showed tendency to localize in the region of the bodies of the lateral ventricles. The least common was laminar GMH. 2. Gray matter heterotopia occurred more often with other developmental disorders of the central nervous system rather than solely. The most frequent concurrent disorders of the central nervous system were: schizencephaly, developmental abnormalities of the corpus callosum, arachnoid cyst, abnormalities of the septum pellucidum and the fornix. 3. GMH foci were more often

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.

Longitudinal Study of Gray Matter Changes in Parkinson Disease.

Science.gov (United States)

Jia, X; Liang, P; Li, Y; Shi, L; Wang, D; Li, K

2015-12-01

The pathology of Parkinson disease leads to morphological brain volume changes. So far, the progressive gray matter volume change across time specific to patients with Parkinson disease compared controls remains unclear. Our aim was to investigate the pattern of gray matter changes in patients with Parkinson disease and to explore the progressive gray matter volume change specific to patients with Parkinson disease with disease progression by using voxel-based morphometry analysis. Longitudinal cognitive assessment and structural MR imaging of 89 patients with Parkinson disease (62 men) and 55 healthy controls (33 men) were from the Parkinson's Progression Markers Initiative data base, including the initial baseline and 12-month follow-up data. Two-way analysis of covariance was performed with covariates of age, sex, years of education, imaging data from multiple centers, and total intracranial volume by using Diffeomorphic Anatomical Registration Through Exponentiated Lie Algebra tool from SPM8 software. Gray matter volume changes for patients with Parkinson disease were detected with decreased gray matter volume in the frontotemporoparietal areas and the bilateral caudate, with increased gray matter volume in the bilateral limbic/paralimbic areas, medial globus pallidus/putamen, and the right occipital cortex compared with healthy controls. Progressive gray matter volume decrease in the bilateral caudate was found for both patients with Parkinson disease and healthy controls, and this caudate volume was positively associated with cognitive ability for both groups. The progressive gray matter volume increase specific to the patients with Parkinson disease was identified close to the left ventral lateral nucleus of thalamus, and a positive relationship was found between the thalamic volume and the tremor scores in a subgroup with tremor-dominant patients with Parkinson disease. The observed progressive changes in gray matter volume in Parkinson disease may provide

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&...

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.

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

Science.gov (United States)

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.

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.

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...

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.

Gray matter heterotopias: MR and clinical features

International Nuclear Information System (INIS)

Moon, Tae Myung; Yoon, Jeong Hee; Chung, Chun Phil

1995-01-01

To evaluate types of gray matter heterotopias, associated brain anomalies, and its correlation with the patterns of seizure. We evaluated retrospectively 19 patients (male:female=10:9, mean age 21 years) with gray matter heterotopias on brain MRI. Using 1.0T superconducting MR unit, spin echo T1-, proton -density and T2-weighted images in axial, coronal and sagittal planes were obtained. Types of gray matter heterotopias were single subependymal in four patients, multiple subependymal in one, focal subcortical in eight, diffuse subcortical in two, mixed multiple subependymal and focal subcortical in four. Associated anomalies were seen in 11 patients: other neuronal migration anomalies in eight patients, corpus callosum agenesis in two, and combined holoprosencephaly and Dandy-Walker malformation in one. Fifteen patients had seizure. The patterns of seizure were not correlated with the types of heterotopias. In addition to subependymal, focal subcortical, and diffuse subcortical types, gray matter heterotopias included mixed variant of multiple subependymal and subcortical type. Schizencephaly was the most common form of accompanying anomalies, and patterns of seizure were not correlated with types of gray matter heterotopias, even though main clinical manifestation was seizure

Secure Data Encryption Through a Combination of AES, RSA and HMAC

Directory of Open Access Journals (Sweden)

E. S. I. Harba

2017-08-01

Full Text Available Secure file transfer based upon well-designed file encryption and authorization systems expend considerable effort to protect passwords and other credentials from being stolen. Transferring and storing passwords in plaintext form leaves them at risk of exposure to attackers, eavesdroppers and spyware. In order to avoid such exposure, powerful encryption/authentication systems use various mechanisms to minimize the possibility that unencrypted credentials will be exposed, as well as be sure that any authentication data that does get transmitted and stored will be of minimal use to an attacker. In this paper we proposed a method to protect data transferring by three hybrid encryption techniques: symmetric AES algorithm used to encrypt files, asymmetric RSA used to encrypt AES password and HMAC to encrypt symmetric password and/or data to ensure a secure transmitting between server-client or client-client from verifying in-between client and server and make it hard to attack by common attacked methods.

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

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.

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)

Prefrontal gray matter volume mediates genetic risks for obesity.

Science.gov (United States)

Opel, N; Redlich, R; Kaehler, C; Grotegerd, D; Dohm, K; Heindel, W; Kugel, H; Thalamuthu, A; Koutsouleris, N; Arolt, V; Teuber, A; Wersching, H; Baune, B T; Berger, K; Dannlowski, U

2017-05-01

Genetic and neuroimaging research has identified neurobiological correlates of obesity. However, evidence for an integrated model of genetic risk and brain structural alterations in the pathophysiology of obesity is still absent. Here we investigated the relationship between polygenic risk for obesity, gray matter structure and body mass index (BMI) by the use of univariate and multivariate analyses in two large, independent cohorts (n=330 and n=347). Higher BMI and higher polygenic risk for obesity were significantly associated with medial prefrontal gray matter decrease, and prefrontal gray matter was further shown to significantly mediate the effect of polygenic risk for obesity on BMI in both samples. Building on this, the successful individualized prediction of BMI by means of multivariate pattern classification algorithms trained on whole-brain imaging data and external validations in the second cohort points to potential clinical applications of this imaging trait marker.

FPGA BASED HARDWARE KEY FOR TEMPORAL ENCRYPTION

Directory of Open Access Journals (Sweden)

B. Lakshmi

2010-09-01

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

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.

MIA - A free and open source software for gray scale medical image analysis.

Science.gov (United States)

Wollny, Gert; Kellman, Peter; Ledesma-Carbayo, María-Jesus; Skinner, Matthew M; Hublin, Jean-Jaques; Hierl, Thomas

2013-10-11

Gray scale images make the bulk of data in bio-medical image analysis, and hence, the main focus of many image processing tasks lies in the processing of these monochrome images. With ever improving acquisition devices, spatial and temporal image resolution increases, and data sets become very large.Various image processing frameworks exists that make the development of new algorithms easy by using high level programming languages or visual programming. These frameworks are also accessable to researchers that have no background or little in software development because they take care of otherwise complex tasks. Specifically, the management of working memory is taken care of automatically, usually at the price of requiring more it. As a result, processing large data sets with these tools becomes increasingly difficult on work station class computers.One alternative to using these high level processing tools is the development of new algorithms in a languages like C++, that gives the developer full control over how memory is handled, but the resulting workflow for the prototyping of new algorithms is rather time intensive, and also not appropriate for a researcher with little or no knowledge in software development.Another alternative is in using command line tools that run image processing tasks, use the hard disk to store intermediate results, and provide automation by using shell scripts. Although not as convenient as, e.g. visual programming, this approach is still accessable to researchers without a background in computer science. However, only few tools exist that provide this kind of processing interface, they are usually quite task specific, and don't provide an clear approach when one wants to shape a new command line tool from a prototype shell script. The proposed framework, MIA, provides a combination of command line tools, plug-ins, and libraries that make it possible to run image processing tasks interactively in a command shell and to prototype by

System for processing an encrypted instruction stream in hardware

Science.gov (United States)

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

2016-04-12

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

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

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...

Reconstructing the CT number array from gray-level images and its application in PACS

Science.gov (United States)

Chen, Xu; Zhuang, Tian-ge; Wu, Wei

2001-08-01

Although DICOM compliant computed tomography has been prevailing in medical fields nowadays, there are some incompliant ones, from which we could hardly get the raw data and make an apropos interpretation due to the proprietary image format. Under such condition, one usually uses frame grabbers to capture CT images, the results of which could not be freely adjusted by radiologists as the original CT number array could. To alleviate the inflexibility, a new method is presented in this paper to reconstruct the array of CT number from several gray-level images acquired under different window settings. Its feasibility is investigated and a few tips are put forward to correct the errors caused respectively by 'Border Effect' and some hardware problems. The accuracy analysis proves it a good substitution for original CT number array acquisition. And this method has already been successfully used in our newly developing PACS and accepted by the radiologists in clinical use.

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.

Imaging of olfactory bulb and gray matter volumes in brain areas associated with olfactory function in patients with Parkinson's disease and multiple system atrophy

International Nuclear Information System (INIS)

Chen, Shun; Tan, Hong-yu; Wu, Zhuo-hua; Sun, Chong-peng; He, Jian-xun; Li, Xin-chun; Shao, Ming

2014-01-01

We explored if magnetic resonance imaging sequences might aid in the clinical differential diagnosis of idiopathic Parkinson's disease (IPD) and multiple system atrophy (MSA). We measured the volumes of the olfactory bulb, the olfactory tract, and olfaction-associated cortical gray matter in 20 IPD patients, 14 MSA patients, and 12 normal subjects, using high-resolution magnetic resonance imaging sequences in combination with voxel-based statistical analysis. We found that, compared to normal subjects and MSA patients, the volumes of the olfactory bulb and tract were significantly reduced in IPD patients. The gray matter volume of IPD patients decreased in the following order: the olfactory area to the right of the piriform cortex, the right amygdala, the left entorhinal cortex, and the left occipital lobe. Further, the total olfactory bulb volume of IPD patients was associated with the duration of disease. The entorhinal cortical gray matter volume was negatively associated with the UPDRS III score. Conclusion: Structural volumes measured by high-resolution magnetic resonance imaging may potentially be used for differential diagnosis of IPD from MSA

Imaging of olfactory bulb and gray matter volumes in brain areas associated with olfactory function in patients with Parkinson's disease and multiple system atrophy

Energy Technology Data Exchange (ETDEWEB)

Chen, Shun, E-mail: shchen_2013@163.com [Department of Neurology, The First Affiliated Hospital of Guangzhou Medical College (China); Tan, Hong-yu, E-mail: honhyutan@21cn.com [Department of Neurology, The First Affiliated Hospital of Guangzhou Medical College (China); Wu, Zhuo-hua, E-mail: zhh88@126.com [Department of Neurology, The First Affiliated Hospital of Guangzhou Medical College (China); Sun, Chong-peng, E-mail: Suncp2002@gmail.com [Imaging Center, The First Affiliated Hospital of Guangzhou Medical College (China); He, Jian-xun, E-mail: xundog@163.com [Imaging Center, The First Affiliated Hospital of Guangzhou Medical College (China); Li, Xin-chun, E-mail: xinchunli@163.com [Imaging Center, The First Affiliated Hospital of Guangzhou Medical College (China); Shao, Ming, E-mail: yimshao@126.com [Department of Neurology, The First Affiliated Hospital of Guangzhou Medical College (China)

2014-03-15

We explored if magnetic resonance imaging sequences might aid in the clinical differential diagnosis of idiopathic Parkinson's disease (IPD) and multiple system atrophy (MSA). We measured the volumes of the olfactory bulb, the olfactory tract, and olfaction-associated cortical gray matter in 20 IPD patients, 14 MSA patients, and 12 normal subjects, using high-resolution magnetic resonance imaging sequences in combination with voxel-based statistical analysis. We found that, compared to normal subjects and MSA patients, the volumes of the olfactory bulb and tract were significantly reduced in IPD patients. The gray matter volume of IPD patients decreased in the following order: the olfactory area to the right of the piriform cortex, the right amygdala, the left entorhinal cortex, and the left occipital lobe. Further, the total olfactory bulb volume of IPD patients was associated with the duration of disease. The entorhinal cortical gray matter volume was negatively associated with the UPDRS III score. Conclusion: Structural volumes measured by high-resolution magnetic resonance imaging may potentially be used for differential diagnosis of IPD from MSA.

Medial frontal white and gray matter contributions to general intelligence.

Directory of Open Access Journals (Sweden)

Toshiyuki Ohtani

Full Text Available The medial orbitofrontal cortex (mOFC and rostral anterior cingulate cortex (rACC are part of a wider neural network that plays an important role in general intelligence and executive function. We used structural brain imaging to quantify magnetic resonance gray matter volume and diffusion tensor white matter integrity of the mOFC-rACC network in 26 healthy participants who also completed neuropsychological tests of intellectual abilities and executive function. Stochastic tractography, the most effective Diffusion Tensor Imaging method for examining white matter connections between adjacent gray matter regions, was employed to assess the integrity of mOFC-rACC pathways. Fractional anisotropy (FA, which reflects the integrity of white matter connections, was calculated. Results indicated that higher intelligence correlated with greater gray matter volumes for both mOFC and rACC, as well as with increased FA for left posterior mOFC-rACC connectivity. Hierarchical regression analyses revealed that DTI-derived FA of left posterior mOFC-rACC uniquely accounted for 29%-34% of the variance in IQ, in comparison to 11%-16% uniquely explained by gray matter volume of the left rACC. Together, left rACC gray matter volume and white matter connectivity between left posterior mOFC and rACC accounted for up to 50% of the variance in general intelligence. This study is to our knowledge the first to examine white matter connectivity between OFC and ACC, two gray matter regions of interests that are very close in physical proximity, and underscores the important independent contributions of variations in rACC gray matter volume and mOFC-rACC white matter connectivity to individual differences in general intelligence.

Correlation between white matter damage and gray matter lesions in multiple sclerosis patients

Directory of Open Access Journals (Sweden)

Xue-mei Han

2017-01-01

Full Text Available We observed the characteristics of white matter fibers and gray matter in multiple sclerosis patients, to identify changes in diffusion tensor imaging fractional anisotropy values following white matter fiber injury. We analyzed the correlation between fractional anisotropy values and changes in whole-brain gray matter volume. The participants included 20 patients with relapsing-remitting multiple sclerosis and 20 healthy volunteers as controls. All subjects underwent head magnetic resonance imaging and diffusion tensor imaging. Our results revealed that fractional anisotropy values decreased and gray matter volumes were reduced in the genu and splenium of corpus callosum, left anterior thalamic radiation, hippocampus, uncinate fasciculus, right corticospinal tract, bilateral cingulate gyri, and inferior longitudinal fasciculus in multiple sclerosis patients. Gray matter volumes were significantly different between the two groups in the right frontal lobe (superior frontal, middle frontal, precentral, and orbital gyri, right parietal lobe (postcentral and inferior parietal gyri, right temporal lobe (caudate nucleus, right occipital lobe (middle occipital gyrus, right insula, right parahippocampal gyrus, and left cingulate gyrus. The voxel sizes of atrophic gray matter positively correlated with fractional anisotropy values in white matter association fibers in the patient group. These findings suggest that white matter fiber bundles are extensively injured in multiple sclerosis patients. The main areas of gray matter atrophy in multiple sclerosis are the frontal lobe, parietal lobe, caudate nucleus, parahippocampal gyrus, and cingulate gyrus. Gray matter atrophy is strongly associated with white matter injury in multiple sclerosis patients, particularly with injury to association fibers.

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