Image Encryption Using a Lightweight Stream Encryption Algorithm
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.
An algorithm for encryption of secret images into meaningful images
Kanso, A.; Ghebleh, M.
2017-03-01
Image encryption algorithms typically transform a plain image into a noise-like cipher image, whose appearance is an indication of encrypted content. Bao and Zhou [Image encryption: Generating visually meaningful encrypted images, Information Sciences 324, 2015] propose encrypting the plain image into a visually meaningful cover image. This improves security by masking existence of encrypted content. Following their approach, we propose a lossless visually meaningful image encryption scheme which improves Bao and Zhou's algorithm by making the encrypted content, i.e. distortions to the cover image, more difficult to detect. Empirical results are presented to show high quality of the resulting images and high security of the proposed algorithm. Competence of the proposed scheme is further demonstrated by means of comparison with Bao and Zhou's scheme.
ALGORITHM FOR IMAGE MIXING AND ENCRYPTION
Ayman M. Abdalla
2013-04-01
Full Text Available This new algorithm mixes two or more images of different types and sizes by employing a shuffling procedure combined with S-box substitution to perform lossless image encryption. This combines stream cipher with block cipher, on the byte level, in mixing the images. When this algorithm was implemented, empirical analysis using test images of different types and sizes showed that it is effective and resistant to attacks.
Novel permutation measures for image encryption algorithms
Abd-El-Hafiz, Salwa K.; AbdElHaleem, Sherif H.; Radwan, Ahmed G.
2016-10-01
This paper proposes two measures for the evaluation of permutation techniques used in image encryption. First, a general mathematical framework for describing the permutation phase used in image encryption is presented. Using this framework, six different permutation techniques, based on chaotic and non-chaotic generators, are described. The two new measures are, then, introduced to evaluate the effectiveness of permutation techniques. These measures are (1) Percentage of Adjacent Pixels Count (PAPC) and (2) Distance Between Adjacent Pixels (DBAP). The proposed measures are used to evaluate and compare the six permutation techniques in different scenarios. The permutation techniques are applied on several standard images and the resulting scrambled images are analyzed. Moreover, the new measures are used to compare the permutation algorithms on different matrix sizes irrespective of the actual parameters used in each algorithm. The analysis results show that the proposed measures are good indicators of the effectiveness of the permutation technique.
Quantum Image Encryption Algorithm Based on Quantum Image XOR Operations
Gong, Li-Hua; He, Xiang-Tao; Cheng, Shan; Hua, Tian-Xiang; Zhou, Nan-Run
2016-07-01
A novel encryption algorithm for quantum images based on quantum image XOR operations is designed. The quantum image XOR operations are designed by using the hyper-chaotic sequences generated with the Chen's hyper-chaotic system to control the control-NOT operation, which is used to encode gray-level information. The initial conditions of the Chen's hyper-chaotic system are the keys, which guarantee the security of the proposed quantum image encryption algorithm. Numerical simulations and theoretical analyses demonstrate that the proposed quantum image encryption algorithm has larger key space, higher key sensitivity, stronger resistance of statistical analysis and lower computational complexity than its classical counterparts.
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.
Review: Image Encryption Using Chaos Based algorithms
Er. Ankita Gaur
2014-03-01
Full Text Available Due to the development in the field of network technology and multimedia applications, every minute thousands of messages which can be text, images, audios, videos are created and transmitted over wireless network. Improper delivery of the message may leads to the leakage of important information. So encryption is used to provide security. In last few years, variety of image encryption algorithms based on chaotic system has been proposed to protect image from unauthorized access. 1-D chaotic system using logistic maps has weak security, small key space and due to the floating of pixel values, some data lose occurs and proper decryption of image becomes impossible. In this paper different chaotic maps such as Arnold cat map, sine map, logistic map, tent map have been studied.
Meteosat Images Encryption based on AES and RSA Algorithms
Boukhatem Mohammed Belkaid
2015-06-01
Full Text Available Satellite image Security is playing a vital role in the field of communication system and Internet. This work is interested in securing transmission of Meteosat images on the Internet, in public or local networks. To enhance the security of Meteosat transmission in network communication, a hybrid encryption algorithm based on Advanced Encryption Standard (AES and Rivest Shamir Adleman (RSA algorithms is proposed. AES algorithm is used for data transmission because of its higher efficiency in block encryption and RSA algorithm is used for the encryption of the key of the AES because of its management advantages in key cipher. Our encryption system generates a unique password every new session of encryption. Cryptanalysis and various experiments have been carried out and the results were reported in this paper, which demonstrate the feasibility and flexibility of the proposed scheme.
Image encryption a communication perspective
Abd El-Samie, Fathi E; Elashry, Ibrahim F; Shahieen, Mai H; Faragallah, Osama S; El-Rabaie, El-Sayed M; Alshebeili, Saleh A
2013-01-01
Presenting encryption algorithms with diverse characteristics, Image Encryption: A Communication Perspective examines image encryption algorithms for the purpose of secure wireless communication. It considers two directions for image encryption: permutation-based approaches encryption and substitution-based approaches.Covering the spectrum of image encryption principles and techniques, the book compares image encryption with permutation- and diffusion-based approaches. It explores number theory-based encryption algorithms such as the Data Encryption Standard, the Advanced Encryption Standard,
A novel image encryption algorithm based on DNA subsequence operation.
Zhang, Qiang; Xue, Xianglian; Wei, Xiaopeng
2012-01-01
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.
A Novel Image Encryption Algorithm Based on DNA Subsequence Operation
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.
Design and Implementation of Image Encryption Algorithm Using Chaos
Sandhya Rani M.H.
2014-06-01
Full Text Available Images are widely used in diverse areas such as medical, military, science, engineering, art, advertising, entertainment, education as well as training, increasing the use of digital techniques for transmitting and storing images. So maintaining the confidentiality and integrity of images has become a major concern. This makes encryption necessary. The pixel values of neighbouring pixels in a plain image are strongly correlated. The proposed algorithm breaks this correlation increasing the entropy. Correlation is reduced by changing the pixel position this which is called confusion. Histogram is equalized by changing the pixel value this which is called diffusion. The proposed method of encryption algorithm is based on chaos theory. The plain-image is divided into blocks and then performs three levels of shuffling using different chaotic maps. In the first level the pixels within the block are shuffled. In the second level the blocks are shuffled and in the third level all the pixels in an image are shuffled. Finally the shuffled image is diffused using a chaotic sequence generated using symmetric keys, to produce the ciphered image for transmission. The experimental result demonstrates that the proposed algorithm can be used successfully to encrypt/decrypt the images with the secret keys. The analysis of the algorithm also shows that the algorithm gives larger key space and a high key sensitivity. The encrypted image has good encryption effect, information entropy and low correlation coefficient.
Chaotic Image Encryption Design Using Tompkins-Paige Algorithm
Shahram Etemadi Borujeni
2009-01-01
Full Text Available In this paper, we have presented a new permutation-substitution image encryption architecture using chaotic maps and Tompkins-Paige algorithm. The proposed encryption system includes two major parts, chaotic pixels permutation and chaotic pixels substitution. A logistic map is used to generate a bit sequence, which is used to generate pseudorandom numbers in Tompkins-Paige algorithm, in 2D permutation phase. Pixel substitution phase includes two process, the tent pseudorandom image (TPRI generator and modulo addition operation. All parts of the proposed chaotic encryption system are simulated. Uniformity of the histogram of the proposed encrypted image is justified using the chi-square test, which is less than 2(255, 0.05. The vertical, horizontal, and diagonal correlation coefficients, as well as their average and RMS values for the proposed encrypted image are calculated that is about 13% less than previous researches. To quantify the difference between the encrypted image and the corresponding plain-image, three measures are used. These are MAE, NPCR, and UACI, which are improved in our proposed system considerably. NPCR of our proposed system is exactly the ideal value of this criterion. The key space of our proposed method is large enough to protect the system against any Brute-force and statistical attacks.
Analyzing the Efficiency of Text-to-Image Encryption Algorithm
Ahmad Abusukhon
2012-12-01
Full Text Available Today many of the activities are performed online through the Internet. One of the methods used to protect the data while sending it through the Internet is cryptography. In a previous work we proposed the Text-to-Image Encryption algorithm (TTIE as a novel algorithm for network security. In this paper we investigate the efficiency of (TTIE for large scale collection.
A chaos-based image encryption algorithm using alternate structure
ZHANG YiWei; WANG YuMin; SHEN XuBang
2007-01-01
Combined with two chaotic maps, a novel alternate structure is applied to image cryptosystem. In proposed algorithm, a general cat-map is used for permutation and diffusion, as well as the OCML (one-way coupled map lattice), which is applied for substitution. These two methods are operated alternately in every round of encryption process, where two subkeys employed in different chaotic maps are generated through the masterkey spreading. Decryption has the same structure with the encryption algorithm, but the masterkey in each round should be reversely ordered in decryption. The cryptanalysis shows that the proposed algorithm bears good immunities to many forms of attacks. Moreover, the algorithm features high execution speed and compact program, which is suitable for various software and hardware applications.
An Improved Piecewise Linear Chaotic Map Based Image Encryption Algorithm
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.
A bit-level image encryption algorithm based on spatiotemporal chaotic system and self-adaptive
Teng, Lin; Wang, Xingyuan
2012-09-01
This paper proposes a bit-level image encryption algorithm based on spatiotemporal chaotic system which is self-adaptive. We use a bit-level encryption scheme to reduce the volume of data during encryption and decryption in order to reduce the execution time. We also use the adaptive encryption scheme to make the ciphered image dependent on the plain image to improve performance. Simulation results show that the performance and security of the proposed encryption algorithm can encrypt plaintext effectively and resist various typical attacks.
An improved image encryption algorithm based on chaotic maps
Xu Shu-Jiang; Wang Ji-Zhi; Yang Su-Xiang
2008-01-01
Recently,two chaotic image encryption schemes have been proposed,in which shuffling the positions and changing the grey values of image pixels are combined.This paper provides the chosen plaintext attack to recover the corresponding plaintext of a given ciphertext.Furthermore,it points out that the two schemes are not sufficiently sensitive to small changes of the plaintext.Based on the given analysis,it proposes an improved algorithm which includes two rounds of substitution and one round of permutation to strengthen the overall performance.
A New Algorithm of Encryption and Decryption of Images Using Chaotic Mapping
Musheer Ahmad
2010-01-01
Full Text Available The combination of chaotic theory and cryptography forms an important field of information security. In the past decade, chaos based image encryption is given much attention in the research of information security and a lot of image encryption algorithms based on chaotic maps have been proposed. Due to some inherent features of images like bulk data capacity and high data redundancy, the encryption of images is different from that of texts; therefore it is difficult to handle them by traditional encryption methods. In this communication, a new image encryption algorithm based on three different chaotic maps is proposed. In the proposed algorithm, the plain-image is first decomposed into 8x8 size blocks and then the block based shuffling of image is carried out using 2D Cat map. Further, the control parameters of shuffling are randomly generated by employing 2D coupled Logistic map. After that the shuffled image is encrypted using chaotic sequence generated by one-dimensional Logistic map. The experimental results show that the proposed algorithm can successfully encrypt/decrypt the images with same secret keys, and the algorithm has good encryption effect, large key space and high sensitivity to a small change in secret keys. Moreover, the simulation analysis also demonstrates that the encrypted images have good information entropy, very low correlation coefficients and the distribution of gray values of an encrypted image has random-like behavior.
A fast image encryption algorithm based on chaotic map
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.
Bouslimi, D; Coatrieux, G; Roux, Ch
2011-01-01
In this paper, we propose a new joint watermarking/encryption algorithm for the purpose of verifying the reliability of medical images in both encrypted and spatial domains. It combines a substitutive watermarking algorithm, the quantization index modulation (QIM), with a block cipher algorithm, the Advanced Encryption Standard (AES), in CBC mode of operation. The proposed solution gives access to the outcomes of the image integrity and of its origins even though the image is stored encrypted. Experimental results achieved on 8 bits encoded Ultrasound images illustrate the overall performances of the proposed scheme. By making use of the AES block cipher in CBC mode, the proposed solution is compliant with or transparent to the DICOM standard.
Tan, Ru-Chao; Lei, Tong; Zhao, Qing-Min; Gong, Li-Hua; Zhou, Zhi-Hong
2016-12-01
To improve the slow processing speed of the classical image encryption algorithms and enhance the security of the private color images, a new quantum color image encryption algorithm based on a hyper-chaotic system is proposed, in which the sequences generated by the Chen's hyper-chaotic system are scrambled and diffused with three components of the original color image. Sequentially, the quantum Fourier transform is exploited to fulfill the encryption. Numerical simulations show that the presented quantum color image encryption algorithm possesses large key space to resist illegal attacks, sensitive dependence on initial keys, uniform distribution of gray values for the encrypted image and weak correlation between two adjacent pixels in the cipher-image.
Wang, Xiaogang; Zhao, Daomu
2012-05-21
A double-image encryption technique that based on an asymmetric algorithm is proposed. In this method, the encryption process is different from the decryption and the encrypting keys are also different from the decrypting keys. In the nonlinear encryption process, the images are encoded into an amplitude cyphertext, and two phase-only masks (POMs) generated based on phase truncation are kept as keys for decryption. By using the classical double random phase encoding (DRPE) system, the primary images can be collected by an intensity detector that located at the output plane. Three random POMs that applied in the asymmetric encryption can be safely applied as public keys. Simulation results are presented to demonstrate the validity and security of the proposed protocol.
A Color Image Encryption Algorithm Based on a Fractional-Order Hyperchaotic System
Xia Huang
2014-12-01
Full Text Available In this paper, a new color image encryption algorithm based on a fractional-order hyperchaotic system is proposed. Firstly, four chaotic sequences are generated by a fractional-order hyperchaotic system. The parameters of such a system, together with the initial value, are regarded as the secret keys and the plain image is encrypted by performing the XOR and shufﬂing operations simultaneously. The proposed encryption scheme is described in detail with security analyses, including correlation analysis, histogram analysis, differential attacks, and key sensitivity analysis. Experimental results show that the proposed encryption scheme has big key space, and high sensitivity to keys properties, and resists statistical analysis and differential attacks, so it has high security and is suitable for color image encryption.
Su, Yonggang; Tang, Chen; Chen, Xia; Li, Biyuan; Xu, Wenjun; Lei, Zhenkun
2017-01-01
We propose an image encryption scheme using chaotic phase masks and cascaded Fresnel transform holography based on a constrained optimization algorithm. In the proposed encryption scheme, the chaotic phase masks are generated by Henon map, and the initial conditions and parameters of Henon map serve as the main secret keys during the encryption and decryption process. With the help of multiple chaotic phase masks, the original image can be encrypted into the form of a hologram. The constrained optimization algorithm makes it possible to retrieve the original image from only single frame hologram. The use of chaotic phase masks makes the key management and transmission become very convenient. In addition, the geometric parameters of optical system serve as the additional keys, which can improve the security level of the proposed scheme. Comprehensive security analysis performed on the proposed encryption scheme demonstrates that the scheme has high resistance against various potential attacks. Moreover, the proposed encryption scheme can be used to encrypt video information. And simulations performed on a video in AVI format have also verified the feasibility of the scheme for video encryption.
Optical multiple-image encryption based on phase encoding algorithm in the Fresnel transform domain
Huang, Jian-Ji; Hwang, Hone-Ene; Chen, Chun-Yuan; Chen, Ching-Mu
2012-10-01
A novel method of the optical multiple-image encryption based on the modified Gerchberg-Saxton algorithm (MGSA) is presented. This proposed method with an architecture of two adjacent phase only functions (POFs) in the Fresnel transform (FrT) domain that can extremely increase capacity of system for completely avoiding the crosstalk between the decrypted images. Each encrypted target image is separately encoded into a POF by using the MGSA which is with constraining the encrypted target image. Each created POF is then added to a prescribed fixed POF composed of a proposed MGSA-based phase encoding algorithm. Not only the wavelength and multiple-position parameters in the FrT domain as keys to increase system security, the created POFs are also served mutually as the encryption keys to decrypt target image based on cascading two POFs scheme. Compared with prior methods [23,24], the main advantages of this proposed encryption system is that it does not need any transformative lenses and that makes it very efficient and easy to implement optically. Simulation results show that this proposed encryption system can successfully achieve the multiple-image encryption with multiple-position keys, which is more advantageous in security than previous work [24] for its decryption process with only two POFs keys to accomplish this task.
Security analysis of image encryption based on two-dimensional chaotic maps and improved algorithm
Feng HUANG; Yong FENG
2009-01-01
The article proposes a new algorithm to improve the security of image encryption based on two-dimensional chaotic maps.Chaotic maps are often used in encrypting images.However,the encryption has periodic-ity,no diffusion,and at the same time,the real keys space of encryption are fewer than the theoretical keys space,which consequently results in potential security problems.Thus,this article puts forward several ways to solve the problems including adding diffusion mechanism,changing the design of keys and developing a composite encryption system.It designs an algorithm for the version B of the discretized baker map,which is one of the most prevalent chaotic maps,based on which a new image encryption is proposed to avoid the above problems.The simulation results show that the new encryption algorithm is valid and the result can be applied to other two-dimensional chaotic maps,such as the cat map.
A Novel Image Encryption Algorithm Based on DNA Encoding and Spatiotemporal Chaos
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 Novel Color Image Encryption Algorithm Based on Quantum Chaos Sequence
Liu, Hui; Jin, Cong
2017-03-01
In this paper, a novel algorithm of image encryption based on quantum chaotic is proposed. The keystreams are generated by the two-dimensional logistic map as initial conditions and parameters. And then general Arnold scrambling algorithm with keys is exploited to permute the pixels of color components. In diffusion process, a novel encryption algorithm, folding algorithm, is proposed to modify the value of diffused pixels. In order to get the high randomness and complexity, the two-dimensional logistic map and quantum chaotic map are coupled with nearest-neighboring coupled-map lattices. Theoretical analyses and computer simulations confirm that the proposed algorithm has high level of security.
Texture Analysis of Chaotic Coupled Map Lattices Based Image Encryption Algorithm
Khan, Majid; Shah, Tariq; Batool, Syeda Iram
2014-09-01
As of late, data security is key in different enclosures like web correspondence, media frameworks, therapeutic imaging, telemedicine and military correspondence. In any case, a large portion of them confronted with a few issues, for example, the absence of heartiness and security. In this letter, in the wake of exploring the fundamental purposes of the chaotic trigonometric maps and the coupled map lattices, we have presented the algorithm of chaos-based image encryption based on coupled map lattices. The proposed mechanism diminishes intermittent impact of the ergodic dynamical systems in the chaos-based image encryption. To assess the security of the encoded image of this scheme, the association of two nearby pixels and composition peculiarities were performed. This algorithm tries to minimize the problems arises in image encryption.
A Brief Study of Video Encryption Algorithms
Pranali Pasalkar,
2015-02-01
Full Text Available Video is a set of images .Video encryption is encrypting those set of images .Thus video encryption is simply hiding your video from prying eyes .Video monitoring has always been in concerned .Multimedia security is very important for multimedia commerce on Internet such as video on demand and Real time video multicast. There are various video encryption algorithm. All have some kind of weakness .In this paper classification of various existing algorithm, its advantages and disadvantages is discussed.
Image Encryption Algorithm Based on Dynamic DNA Coding and Chen’s Hyperchaotic System
Jian Zhang
2016-01-01
Full Text Available With the development of national information processes, specific image information from secret departments or individuals is often required to be confidentially transmitted. Numerous image encryption methods exist, especially since the initial value sensitivity and other characteristics of chaos theory and chaos theory-based encryption have become increasingly important in recent years. At present, DNA coding constitutes a new research direction of image encryption that uses the four base pairs of DNA code and image pixel values to establish a special correspondence, in order to achieve pixel diffusion. There are eight DNA encoding rules, and current methods of selecting the DNA encoding rules are largely fixed. Thus, the security of encoded data is not high. In this paper, we use the Lorenz chaotic system, Chen’s hyperchaotic system, and the DNA encoding combination and present a new image encryption algorithm that can dynamically select eight types of DNA encoding rules and eight types of DNA addition and subtraction rules, with significant improvements in security. Through simulation experiments and histograms, correlations, and NPCR analyses, we have determined that the algorithm possesses numerous desirable features, including good encryption effects and antishear and antinoise performances.
Optical image encryption topology.
Yong-Liang, Xiao; Xin, Zhou; Qiong-Hua, Wang; Sheng, Yuan; Yao-Yao, Chen
2009-10-15
Optical image encryption topology is proposed based on the principle of random-phase encoding. Various encryption topological units, involving peer-to-peer, ring, star, and tree topologies, can be realized by an optical 6f system. These topological units can be interconnected to constitute an optical image encryption network. The encryption and decryption can be performed in both digital and optical methods.
Ding Lu; Weimin Jin
2011-01-01
A novel fully phase color image encryption/decryption scheme based on joint fractional Fourier transform correlator (JFRTC) and phase retrieval algorithm (PRA) is proposed. The security of the system is enhanced by the fractional order as a new added key. This method takes full advantage of the parallel processing features of the optical system and could optically realize single-channel color image encryption.The system and operation procedures are simplified. The simulation results of a color image indicate that the new method provides efficient solutions with a strong sense of security.%@@ A novel fully phase color image encryption/decryption scheme based on joint fractional Fourier transform correlator (JFRTC) and phase retrieval algorithm (PRA) is proposed. The security of the system is enhanced by the fractional order as a new added key. This method takes full advantage of the parallel processing features of the optical system and could optically realize single-channel color image encryption. The system and operation procedures are simplified. The simulation results of a color image indicate that the new method provides efficient solutions with a strong sense of security.
Bouslimi, Dalel; Coatrieux, Gouenou; Roux, Christian
2012-04-01
In this paper we propose a joint encryption/watermarking algorithm for the purpose of protecting medical images. The proposed solution gives access to the outcomes of the image integrity and of its origins as its attachment to one patient even if the image is stored encrypted. In this study, the given solution combines the RC4 stream cipher and two substitutive watermarking modulations: the Least Significant Bit Method and the Quantization Index Modulation. If watermarking and encryption are conducted jointly at the protection stage, watermark extraction and decryption can be applied independently. Experimental results achieved on 8 bits encoded echographic images illustrate the overall performances of the proposed scheme. At least, a capacity rate of 1 and 0.5 bits of message per pixel of image can be embedded in the spatial and the encrypted domains respectively, with a peak signal to noise ratio greater than 49 dB.
A novel image encryption algorithm based on chaos maps with Markov properties
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.
A novel chaotic block image encryption algorithm based on dynamic random growth technique
Wang, Xingyuan; Liu, Lintao; Zhang, Yingqian
2015-03-01
This paper proposes a new block image encryption scheme based on hybrid chaotic maps and dynamic random growth technique. Since cat map is periodic and can be easily cracked by chosen plaintext attack, we use cat map in another securer way, which can completely eliminate the cyclical phenomenon and resist chosen plaintext attack. In the diffusion process, an intermediate parameter is calculated according to the image block. The intermediate parameter is used as the initial parameter of chaotic map to generate random data stream. In this way, the generated key streams are dependent on the plaintext image, which can resist the chosen plaintext attack. The experiment results prove that the proposed encryption algorithm is secure enough to be used in image transmission systems.
Reversible Data Hiding In Encrypted Images Using Improved Encryption Technique
Balika J. Chelliah
2015-11-01
Full Text Available Recently more and more attention is paid to reversible data hiding (RDH in encrypted images, since it maintains the excellent property that the original cover can be losslessly recovered after embedded data is extracted while protecting the image content‟s confidentiality. All previous methods embed data by reversibly vacating room from the encrypted images, which may be some errors on data extraction and/or image restoration. In this paper we propose a different scheme which attains real reversibility by reserving room before encryption with a traditional RDH algorithm, and then encrypting the data and embedding the data in the encrypted image, which is encrypted using a new proposed algorithm. The proposed method can achieve real reversibility that is data extraction and image recoveries are free of any error.
Reversible Data Hiding In Encrypted Images Using Improved Encryption Technique
Mr. Balika J. Chelliah
2014-03-01
Full Text Available Recently more and more attention is paid to reversible data hiding (RDH in encrypted images, since it maintains the excellent property that the original cover can be losslessly recovered after embedded data is extracted while protecting the image content‟s confidentiality. All previous methods embed data by reversibly vacating room from the encrypted images, which may be some errors on data extraction and/or image restoration. In this paper we propose a different scheme which attains real reversibility by reserving room before encryption with a traditional RDH algorithm, and then encrypting the data and embedding the data in the encrypted image, which is encrypted using a new proposed algorithm. The proposed method can achieve real reversibility that is data extraction and image recoveries are free of any error.
A Fast Color Image Encryption Algorithm Using 4-Pixel Feistel Structure.
Yao, Wang; Wu, Faguo; Zhang, Xiao; Zheng, Zhiming; Wang, Zhao; Wang, Wenhua; Qiu, Wangjie
2016-01-01
Algorithms using 4-pixel Feistel structure and chaotic systems have been shown to resolve security problems caused by large data capacity and high correlation among pixels for color image encryption. In this paper, a fast color image encryption algorithm based on the modified 4-pixel Feistel structure and multiple chaotic maps is proposed to improve the efficiency of this type of algorithm. Two methods are used. First, a simple round function based on a piecewise linear function and tent map are used to reduce computational cost during each iteration. Second, the 4-pixel Feistel structure reduces round number by changing twist direction securely to help the algorithm proceed efficiently. While a large number of simulation experiments prove its security performance, additional special analysis and a corresponding speed simulation show that these two methods increase the speed of the proposed algorithm (0.15s for a 256*256 color image) to twice that of an algorithm with a similar structure (0.37s for the same size image). Additionally, the method is also faster than other recently proposed algorithms.
Li, Jinqing; Bai, Fengming; Di, Xiaoqiang
2013-01-01
We propose an image encryption/decryption algorithm based on chaotic control parameter and hyperchaotic system with the composite permutation-diffusion structure. Compound chaos mapping is used to generate control parameters in the permutation stage. The high correlation between pixels is shuffled. In the diffusion stage, compound chaos mapping of different initial condition and control parameter generates the diffusion parameters, which are applied to hyperchaotic cellular neural networks. The diffusion key stream is obtained by this process and implements the pixels' diffusion. Compared with the existing methods, both simulation and statistical analysis of our proposed algorithm show that the algorithm has a good performance against attacks and meets the corresponding security level.
A novel chaos-based image encryption algorithm using DNA sequence operations
Chai, Xiuli; Chen, Yiran; Broyde, Lucie
2017-01-01
An image encryption algorithm based on chaotic system and deoxyribonucleic acid (DNA) sequence operations is proposed in this paper. First, the plain image is encoded into a DNA matrix, and then a new wave-based permutation scheme is performed on it. The chaotic sequences produced by 2D Logistic chaotic map are employed for row circular permutation (RCP) and column circular permutation (CCP). Initial values and parameters of the chaotic system are calculated by the SHA 256 hash of the plain image and the given values. Then, a row-by-row image diffusion method at DNA level is applied. A key matrix generated from the chaotic map is used to fuse the confused DNA matrix; also the initial values and system parameters of the chaotic system are renewed by the hamming distance of the plain image. Finally, after decoding the diffused DNA matrix, we obtain the cipher image. The DNA encoding/decoding rules of the plain image and the key matrix are determined by the plain image. Experimental results and security analyses both confirm that the proposed algorithm has not only an excellent encryption result but also resists various typical attacks.
Sharma, K. K.; Jain, Heena
2013-01-01
The security of digital data including images has attracted more attention recently, and many different image encryption methods have been proposed in the literature for this purpose. In this paper, a new image encryption method using wavelet packet decomposition and discrete linear canonical transform is proposed. The use of wavelet packet decomposition and DLCT increases the key size significantly making the encryption more robust. Simulation results of the proposed technique are also presented.
Zhou, Nanrun; Zhang, Aidi; Zheng, Fen; Gong, Lihua
2014-10-01
The existing ways to encrypt images based on compressive sensing usually treat the whole measurement matrix as the key, which renders the key too large to distribute and memorize or store. To solve this problem, a new image compression-encryption hybrid algorithm is proposed to realize compression and encryption simultaneously, where the key is easily distributed, stored or memorized. The input image is divided into 4 blocks to compress and encrypt, then the pixels of the two adjacent blocks are exchanged randomly by random matrices. The measurement matrices in compressive sensing are constructed by utilizing the circulant matrices and controlling the original row vectors of the circulant matrices with logistic map. And the random matrices used in random pixel exchanging are bound with the measurement matrices. Simulation results verify the effectiveness, security of the proposed algorithm and the acceptable compression performance.
A novel image encryption algorithm using chaos and reversible cellular automata
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.
Li, Yueping; Wang, Chunhua; Chen, Hua
2017-03-01
Recently, a number of chaos-based image encryption algorithms that use low-dimensional chaotic map and permutation-diffusion architecture have been proposed. However, low-dimensional chaotic map is less safe than high-dimensional chaotic system. And permutation process is independent of plaintext and diffusion process. Therefore, they cannot resist efficiently the chosen-plaintext attack and chosen-ciphertext attack. In this paper, we propose a hyper-chaos-based image encryption algorithm. The algorithm adopts a 5-D multi-wing hyper-chaotic system, and the key stream generated by hyper-chaotic system is related to the original image. Then, pixel-level permutation and bit-level permutation are employed to strengthen security of the cryptosystem. Finally, a diffusion operation is employed to change pixels. Theoretical analysis and numerical simulations demonstrate that the proposed algorithm is secure and reliable for image encryption.
A joint image encryption and watermarking algorithm based on compressive sensing and chaotic map
Xiao, Di; Cai, Hong-Kun; Zheng, Hong-Ying
2015-06-01
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. Project supported by the Open Research Fund of Chongqing Key Laboratory of Emergency Communications, China (Grant No. CQKLEC, 20140504), the National Natural Science Foundation of China (Grant Nos. 61173178, 61302161, and 61472464), and the Fundamental Research Funds for the Central Universities, China (Grant Nos. 106112013CDJZR180005 and 106112014CDJZR185501).
Optical image encryption based on diffractive imaging.
Chen, Wen; Chen, Xudong; Sheppard, Colin J R
2010-11-15
In this Letter, we propose a method for optical image encryption based on diffractive imaging. An optical multiple random phase mask encoding system is applied, and one of the phase-only masks is selected and laterally translated along a preset direction during the encryption process. For image decryption, a phase retrieval algorithm is proposed to extract a high-quality plaintext. The feasibility and effectiveness of the proposed method are demonstrated by numerical results. The proposed method can provide a new strategy instead of conventional interference methods, and it may open up a new research perspective for optical image encryption.
Proposed Hyperchaotic System for Image Encryption
Asst. Prof. Dr. Alia Karim Abdul Hassan
2016-01-01
Full Text Available This paper presents a new hyper chaos system based on Hénon and Logistic maps which provides characteristics of high capacity, security and efficiency. The Proposed hyper chaos system is employed to generate the key for diffusion in an image encryption algorithm. The simulation experiments to the image encryption algorithm which based on the proposed hyper chaos system show that the algorithm security analysis it has large key space (10 84 that ensures a strong resistance against attack of exhaustion as the key space will be greater, strong sensitivity of encryption key and good statistical characteristics. Encryption and decryption time is suitable for different applications.
Chai, Xiu-Li; Gan, Zhi-Hua; Lu, Yang; Zhang, Miao-Hui; Chen, Yi-Ran
2016-10-01
Recently, many image encryption algorithms based on chaos have been proposed. Most of the previous algorithms encrypt components R, G, and B of color images independently and neglect the high correlation between them. In the paper, a novel color image encryption algorithm is introduced. The 24 bit planes of components R, G, and B of the color plain image are obtained and recombined into 4 compound bit planes, and this can make the three components affect each other. A four-dimensional (4D) memristive hyperchaotic system generates the pseudorandom key streams and its initial values come from the SHA 256 hash value of the color plain image. The compound bit planes and key streams are confused according to the principles of genetic recombination, then confusion and diffusion as a union are applied to the bit planes, and the color cipher image is obtained. Experimental results and security analyses demonstrate that the proposed algorithm is secure and effective so that it may be adopted for secure communication. Project supported by the National Natural Science Foundation of China (Grant Nos. 61203094 and 61305042), the Natural Science Foundation of the United States (Grant Nos. CNS-1253424 and ECCS-1202225), the Science and Technology Foundation of Henan Province, China (Grant No. 152102210048), the Foundation and Frontier Project of Henan Province, China (Grant No. 162300410196), the Natural Science Foundation of Educational Committee of Henan Province, China (Grant No. 14A413015), and the Research Foundation of Henan University, China (Grant No. xxjc20140006).
Saddaf Rubab
2015-01-01
Full Text Available Steganography is a means to hide the existence of information exchange. Using this technique the sender embeds the secret information in some other media. This is done by replacing useless data in ordinary computer files with some other secret information. The secret information could be simple text, encoded text or images. The media used as the embedding plane could be an image, audio, video or text files. Using steganography ensures that no one apart from the sender and the receiver knows about the existence of the message. In this paper, a steganography method based on transforms used i.e. Wavelet and Contourlet. Devised algorithm was used against each transform. Blowfish Encryption method is also embedded to double the security impact. The major advantage of applying transforms is that the image quality is not degraded even if the number of embedded characters is increased. The proposed system operates well in most of the test cases. The average payload capacity is also considerably high.
Performance study of selective encryption in comparison to full encryption for still visual images
Osama A.KHASHAN; Abdullah M.ZIN; Elankovan A.SUNDARARAJAN
2014-01-01
Securing digital images is becoming an important concern in today’s information security due to the extensive use of secure images that are either transmitted over a network or stored on disks. Image encryption is the most effective way to fulfil confidentiality and protect the privacy of images. Nevertheless, owing to the large size and complex structure of digital images, the computational overhead and processing time needed to carry out full image encryption prove to be limiting factors that inhibit it of being used more heavily in real time. To solve this problem, many recent studies use the selective encryption approach to encrypt significant parts of images with a hope to reduce the encryption overhead. However, it is necessary to realistically evaluate its performance compared to full encryption. In this paper, we study the performance and efficiency of image segmentation methods used in the selective encryption approach, such as edges and face detection methods, in determining the most important parts of visual images. Experiments were performed to analyse the computational results obtained by selective image encryption compared to full image encryption using symmetric encryption algorithms. Experiment results have proven that the selective encryption approach based on edge and face detection can significantly reduce the time of encrypting still visual images as compared to full encryption. Thus, this approach can be considered a good alternative in the implementation of real-time applications that require adequate security levels.
IMAGE ENCRYPTION BASED ON SINGULAR VALUE DECOMPOSITION
Nidhal K. El Abbadi
2014-01-01
Full Text Available Image encryption is one of the most methods of information hiding. A novel secure encryption method for image encryption is presented in this study. The proposed algorithm based on using singular value decomposition SVD. In this study we start to scramble the image data according to suggested keys (two sequence scrambling process with two different keys to finally create two different matrices. The diagonal matrix from the SVD will be interchanged with the resulted matrices. Another scrambling and diagonal matrices interchange will apply to increase the complexity. The resulted two matrices combine to one matrix according to predefined procedure. The encrypted image is a meaningfull image. The suggested method tested with many images encryption and gives promised results.
Stream Deniable-Encryption Algorithms
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.
Wang, Yong; Markman, Adam; Quan, Chenggen; Javidi, Bahram
2016-11-01
We present a photon-counting double-random-phase encryption technique that only requires the photon-limited amplitude of the encrypted image for decryption. The double-random-phase encryption is used to encrypt an image, generating a complex image. Photon counting is applied to the amplitude of the encrypted image, generating a sparse noise-like image; however, the phase information is not retained. By not using the phase information, the encryption process is simplified, allowing for intensity detection and also less information to be recorded. Using a phase numerically generated from the correct encryption keys together with the photon-limited amplitude of the encrypted image, we are able to decrypt the image. Moreover, nonlinear correlation algorithms can be used to authenticate the decrypted image. Both amplitude-based and full-phase encryption using the proposed method are investigated. Preliminary computational results and performance evaluation are presented.
Spatial chaos-based image encryption design
无
2009-01-01
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, permutation and sub- stitution methods are incorporated to present a stronger image encryption algorithm. Spatial chaotic maps are used to realize the position permutation, and to confuse the relationship between the ci- pher-image and the plain-image. The experimental results demonstrate that the suggested encryption scheme of image has the advantages of large key space and high security; moreover, the distribution of grey values of the encrypted image has a random-like behavior.
Spatial chaos-based image encryption design
LIU ShuTang; SUN FuYan
2009-01-01
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, permutation and sub-stitution methods are incorporated to present a stronger image encryption algorithm. Spatial chaotic maps are used to realize the position permutation, and to confuse the relationship between the ci-pher-image and the plain-image. The experimental results demonstrate that the suggested encryption scheme of image has the advantages of large key space and high security; moreover, the distribution of grey values of the encrypted image has a random-like behavior.
Advanced Steganography Algorithm using Encrypted secret message
Joyshree Nath
2011-03-01
Full Text Available In the present work the authors have introduced a new method for hiding any encrypted secret message inside a cover file. For encrypting secret message the authors have used new algorithm proposed by Nath et al(1. For hiding secret message we have used a method proposed by Nath et al(2. In MSA(1 method we have modified the idea of Play fair method into a new platform where we can encrypt or decrypt any file. We have introduced a new randomization method for generating the randomized key matrix to encrypt plain text file and to decrypt cipher text file. We have also introduced a new algorithm for encrypting the plain text multiple times. Our method is totally dependent on the random text_key which is to be supplied by the user. The maximum length of the text_key can be of 16 characters long and it may contain any character(ASCII code 0 to 255. We have developed an algorithm to calculate the randomization number and the encryption number from the given text_key. The size of the encryption key matrix is 16x16 and the total number of matrices can be formed from 16 x 16 is 256! which is quite large and hence if someone applies the brute force method then he/she has to give trail for 256! times which is quite absurd. Moreover the multiple encryption method makes the system further secured. For hiding secret message in the cover file we have inserted the 8 bits of each character of encrypted message file in 8 consecutive bytes of the cover file. We have introduced password for hiding data in the cover file. We propose that our new method could be most appropriate for hiding any file in any standard cover file such as image, audio, video files. Because the hidden message is encrypted hence it will be almost impossible for the intruder to unhide the actual secret message from the embedded cover file. This method may be the most secured method in digital water marking.
Multiple image encryption by phase retrieval
Di, Hong; Kang, Yanmei; Liu, Yueqin; Zhang, Xin
2016-07-01
Multiple image encryption (MIE) was proposed to increase the efficiency of encrypting images by processing several images simultaneously. Because of the advantage of optical technology in processing twodimensional images at high throughput, MIE has been significantly improved by use of methods originating from optics. Phase retrieval was the process of algorithmically finding solutions to the phase loss problem due to light detectors only capturing the intensity. It was to retrieve phase information for the determination of a structure from diffraction data. Error-reduction algorithm is a typical phase retrieval method. Here, we employ it to illustrate that methods in phase retrieval are able to encrypt multiple images and compress them into encrypted data simultaneously. Moreover, the decryption is also designed to handle multiple images at the same time. The whole process including both the encryption and decryption is proposed to improve MIE with respect to the compression and efficiency. The feasibility and encryption of the MIE scheme is demonstrated with encryption experiments under Gaussian white noise and unauthorized access.
Security enhancement of a phase-truncation based image encryption algorithm.
Wang, Xiaogang; Zhao, Daomu
2011-12-20
The asymmetric cryptosystem, which is based on phase-truncated Fourier transforms (PTFTs), can break the linearity of conventional systems. However, it has been proven to be vulnerable to a specific attack based on iterative Fourier transforms when the two random phase masks are used as public keys to encrypt different plaintexts. An improvement from the asymmetric cryptosystem may be taken by relocating the amplitude values in the output plane. In this paper, two different methods are adopted to realize the amplitude modulation of the output image. The first one is to extend the PTFT-based asymmetrical cryptosystem into the anamorphic fractional Fourier transform domain directly, and the second is to add an amplitude mask in the Fourier plane of the encryption scheme. Some numerical simulations are presented to prove the good performance of the proposed cryptosystems.
Image encryption using P-Fibonacci transform and decomposition
Zhou, Yicong; Panetta, Karen; Agaian, Sos; Chen, C. L. Philip
2012-03-01
Image encryption is an effective method to protect images or videos by transferring them into unrecognizable formats for different security purposes. To improve the security level of bit-plane decomposition based encryption approaches, this paper introduces a new image encryption algorithm by using a combination of parametric bit-plane decomposition along with bit-plane shuffling and resizing, pixel scrambling and data mapping. The algorithm utilizes the Fibonacci P-code for image bit-plane decomposition and the 2D P-Fibonacci transform for image encryption because they are parameter dependent. Any new or existing method can be used for shuffling the order of the bit-planes. Simulation analysis and comparisons are provided to demonstrate the algorithm's performance for image encryption. Security analysis shows the algorithm's ability against several common attacks. The algorithm can be used to encrypt images, biometrics and videos.
Dual encryption scheme of images using polarized light.
Alfalou, A; Brosseau, C
2010-07-01
We propose and analyze a dual encryption/decryption scheme, motivated by recent interest in polarization encoding. Compared to standard optical encryption methods, which are based on phase and amplitude manipulation, this encryption procedure relying on Mueller-Stokes formalism provides large flexibility in the key encryption design. The effectiveness of our algorithm is discussed, thanks to a numerical simulation of the polarization encryption/decryption procedure of a 256 gray-level image. Of additional special interest is the immunity of this encryption algorithm to brute force attacks.
Image Encryption using chaos functions and fractal key
Houman Kashanian
2016-09-01
Full Text Available Many image in recent years are transmitted via internet and stored on it. Maintain the confidentiality of these data has become a major issue. So that encryption algorithms permit only authorized users to access data which is a proper solution to this problem.This paper presents a novel scheme for image encryption. At first, a two dimensional logistic mapping is applied to permutation relations between image pixels. We used a fractal image as an encryption key. Given that the chaotic mapping properties such as extreme sensitivity to initial values, random behavior, non-periodic, certainty and so on, we used theses mappings in order to select fractal key for encryption. Experimental results show that proposed algorithm to encrypt image has many features. Due to features such as large space key, low relations between the pixels of encrypted image, high sensitivity to key and high security, it can effectively protect the encrypted image security.
Chaotic Image Encryption of Regions of Interest
Xiao, Di; Fu, Qingqing; Xiang, Tao; Zhang, Yushu
Since different regions of an image have different importance, therefore only the important information of the image regions, which the users are really interested in, needs to be encrypted and protected emphatically in some special multimedia applications. However, the regions of interest (ROI) are always some irregular parts, such as the face and the eyes. Assuming the bulk data in transmission without being damaged, we propose a chaotic image encryption algorithm for ROI. ROI with irregular shapes are chosen and detected arbitrarily. Then the chaos-based image encryption algorithm with scrambling, S-box and diffusion parts is used to encrypt the ROI. Further, the whole image is compressed with Huffman coding. At last, a message authentication code (MAC) of the compressed image is generated based on chaotic maps. The simulation results show that the encryption algorithm has a good security level and can resist various attacks. Moreover, the compression method improves the storage and transmission efficiency to some extent, and the MAC ensures the integrity of the transmission data.
一种高效的彩色图像加密和解密算法%Efficient Encryption and Decryption Algorithm for Color Image
彭静玉
2013-01-01
分析了基于Arnold变换的加密方案在加密效果及加密效率方面的不足。提出了一种新的彩色图像加密及解密算法。加密过程将像素的物理位置置乱并映射到不同的色彩空间；解密过程提出了一种针对彩色图像的逆变换算法，使解密的时间仅依赖加密的密钥而不依赖变换周期。仿真分析比较了该算法在加密效果及加密效率方面的优势。实验数据表明，该加密算法的加密效果理想，且加密效率较高，是一种简单、可行的彩色图像加密方法。%The deficiencies of encryption scheme based on Arnold transformation is analyzed, and a new encryption/decryption algorithm for color image proposed. The physical locations of pixels are scrambled and mapped to different color spaces in the encryption process. An inverse conversion method for color im-age is suggested in decryption process, thus making the decryption time dependent only on the encryption key instead of on the conversion cycle. Simulation and comparison of the advantages of proposed algorithm in encryption effect and encryption efficiency indicates that the proposed algorithm could improve encryp-tion effect while raising the decryption efficiency, and thus a simple and feasible color image encryption method.
Research on medical image encryption in telemedicine systems.
Dai, Yin; Wang, Huanzhen; Zhou, Zixia; Jin, Ziyi
2016-04-29
Recently, advances in computers and high-speed communication tools have led to enhancements in remote medical consultation research. Laws in some localities require hospitals to encrypt patient information (including images of the patient) before transferring the data over a network. Therefore, developing suitable encryption algorithms is quite important for modern medicine. This paper demonstrates a digital image encryption algorithm based on chaotic mapping, which uses the no-period and no-convergence properties of a chaotic sequence to create image chaos and pixel averaging. Then, the chaotic sequence is used to encrypt the image, thereby improving data security. With this method, the security of data and images can be improved.
基于RSA的数字图像加密算法%An Encryption Algorithm for Digital Image Based on RSA System
杨昔阳; 李志伟
2009-01-01
It proposes a novel encryption method for digital image based on an Arnold scrambling transform, a chaos encryption algorithm and RSA encryption system. The parameters of the Arnold transform and chaos encryption algorithm are encrypted by RSA system and stored in LSB of an image to ensure the security in transmission. The example in this paper shows that the proposed method is an efficient way to encrypt a digital image.%提出一种基于RSA公钥、Arnold置乱变换和混沌加密算法相结合的公开密钥数字图像加密体制,利用客户的公钥对Arnold置乱变换和混沌序列初值进行RSA加密,确保了只有合法用户才能获取置乱参数信息并将图像复原.RSA对参数的加密信息隐藏于图像LSB中,无需另外传递密文,运算简单,具有良好的加密与隐藏效果.
Cryptanalyzing a chaotic encryption algorithm for highly autocorrelated data
Li, Ming; Liu, Shangwang; Niu, Liping; Liu, Hong
2016-12-01
Recently, a chaotic encryption algorithm for highly autocorrelated data was proposed. By adding chaotic diffusion to the former work, the information leakage of the encryption results especially for the images with lower gray scales was eliminated, and both higher-level security and fast encryption time were achieved. In this study, we analyze the security weakness of this scheme. By applying the ciphertext-only attack, the encrypted image can be restored into the substituted image except for the first block; and then, by using the chosen-plaintext attack, the S-boxes, the distribution map, and the block of chaotic map values, can all be revealed, and the encrypted image can be completely cracked. The improvement is also proposed. Experimental results verify our assertion.
Digital Image Encryption Scheme Based on Multiple Chaotic Systems
Abd El-Latif, Ahmed A.; Li, Li; Zhang, Tiejun; Wang, Ning; Song, Xianhua; Niu, Xiamu
2012-06-01
Image encryption is a challenging task due to the significant level of sophistication achieved by forgerers and other cybercriminals. Advanced encryption methods for secure transmission, storage, and retrieval of digital images are increasingly needed for a number of military, medical, homeland security, and other applications. In this paper, we introduce a new digital image encryption algorithm. The new algorithm employs multiple chaotic systems and cryptographic primitive operations within the encryption process, which are efficiently implemented on modern processors, and adopts round keys for encryption using a chaotic map. Experiments conducted show that the proposed algorithm possesses robust security features such as fairly uniform distribution, high sensitivity to both keys and plainimages, almost ideal entropy, and the ability to highly de-correlate adjacent pixels in the cipherimages. Furthermore, it has a large key space, which greatly increases its security for image encryption applications.
Image encryption using high-dimension chaotic system
Sun Fu-Yan; Liu Shu-Tang; Lü Zong-Wang
2007-01-01
In recent years, the chaos based cryptographic algorithms have suggested some new and efficient ways to develop secure image encryption techniques. This paper proposes a new approach for image encryption based on a highdimensional chaotic map. The new scheme employs the Cat map to shuffle the positions, then to confuse the relationship between the cipher-image and the plain-image using the high-dimensional Lorenz chaotic map preprocessed. The results of experimental, statistical analysis and key space analysis show that the proposed image encryption scheme provides an efficient and secure way for real-time image encryption and transmission.
A lossless encryption method for medical images using edge maps.
Zhou, Yicong; Panetta, Karen; Agaian, Sos
2009-01-01
Image encryption is an effective approach for providing security and privacy protection for medical images. This paper introduces a new lossless approach, called EdgeCrypt, to encrypt medical images using the information contained within an edge map. The algorithm can fully protect the selected objects/regions within medical images or the entire medical images. It can also encrypt other types of images such as grayscale images or color images. The algorithm can be used for privacy protection in the real-time medical applications such as wireless medical networking and mobile medical services.
A realizable quantum encryption algorithm for qubits
Zhou Nan-Run; Zeng Gui-Hua
2005-01-01
A realizable quantum encryption algorithm for qubits is presented by employing bit-wise quantum computation.System extension and bit-swapping are introduced into the encryption process, which makes the ciphertext space expanded greatly. The security of the proposed algorithm is analysed in detail and the schematic physical implementation is also provided. It is shown that the algorithm, which can prevent quantum attack strategy as well as classical attack strategy, is effective to protect qubits. Finally, we extend our algorithm to encrypt classical binary bits and quantum entanglements.
Optical image encryption using multilevel Arnold transform and noninterferometric imaging
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.
Image encryption using eight dimensional chaotic cat map
Ganesan, K.; Murali, K.
2014-06-01
In recent years, a large number of discrete chaotic cryptographic algorithms have been proposed. However, most of them encounter some problems such as lack of robustness and security. In this paper, we introduce a new image encryption algorithm based on eight-dimensional (nonlinear) chaotic cat map. Encryption of image is different from that of texts due to some intrinsic features of image such as bulk data capacity and high redundancy, which are generally difficult to handle by traditional methods. In traditional methods the key space is small and the security is weak. The proposed algorithm tries to address these problems and also tries to enhance the encryption speed. In this paper an eight dimensional chaotic cat map is used to encrypt the intensity values of pixels using lookup table method thereby significantly increasing the speed and security of encryption. The proposed algorithm is found to be resistive against chosen/known-plaintext attacks, statistical and differential attacks.
一种多混沌的彩色图像认证加密算法%A Color Image Authentication Encryption Algorithm Based Multi-chaos
蒲昌玖
2013-01-01
In order to protect color image effectively,a color image encryption scheme based on multiple chaotic maps and authentication is presented.The algorithm generated 128-bit Hash keys by the mathematical operation in the RGB components of the color image,and the Hash key is used as part of the image encryption keys.Then,pixels shuffling and pixels substitution are simultaneous implemented to encrypt the color image using Logistic chaotic system,unified chaotic system and Hash keys.Finally,theoretical analyses and simulated experiment show that the color image encryption algorithm shows advantages of larger key space,higher security,a random distribution characteristics of the pixel value of the encrypted image and the zero correlation of adjacent pixels.%为了实现对彩色图像的有效保护,提出一种基于多混沌系统和图像认证功能的彩色图像加密算法.该算法通过对彩色图像RGB分量的运算生成128位Hash值,并把该Hash值作为部分图像加密的密钥.然后通过Logistic混沌系统、统一混沌系统和Hash值对彩色图像进行像素置乱和替代操作以实现图像加密.最后,理论分析和仿真实验结果表明,该加密算法具有密钥空间大,保密性好,加密图像像素值具有类随机均匀分布特性和相邻像素值的零相关特性.
Research on the New Development of Image Encryption Algorithms%图像加密算法研究新进展
张晓强; 王蒙蒙; 朱贵良
2012-01-01
With the rapid development of information netization, image interaction in the Internet is widely applied in many fields. People pay much attention to the security of image interaction. We illustrate the encryption principles, characteristics and new development of the important image encryption algorithms, such as those based on matrix transformation, chaos, image secret sharing, frequency domains, SCAN languages, and DNA computing. Finally, the development trend of image encryption algorithm is discussed in this paper. This study is significant in algorithm improvement, new algorithm design and algorithm selection in the practice of image encryption.%随着信息网络化飞速发展,图像网络交互在诸多领域得到应用,图像交互的安全问题倍受人们关注.本文讨论了基于现代密码体制的图像加密、基于矩阵变换的图像加密、基于混沌的图像加密、基于秘密分存的图像加密、基于频域的图像加密、基于SCAN语言的图像加密和基于DNA计算的图像加密等主流图像加密算法的加密原理、优缺点和最新进展.最后,展望了图像加密算法的发展趋势.该成果对图像加密算法的改进、新算法的研究以及在实际工程中对算法的选取具有重要意义.
Hwang, Hone-Ene; Chang, Hsuan T; Lie, Wen-Nung
2009-12-15
What we believe to be a new technique, based on a modified Gerchberg-Saxton algorithm (MGSA) and a phase modulation scheme in the Fresnel-transform domain, is proposed to reduce cross talks existing in multiple-image encryption and multiplexing. First, each plain image is encoded and multiplexed into a phase function by using the MGSA and a different wavelength/position parameter. Then all the created phase functions are phase modulated to result in different shift amounts of the reconstruction images before being combined together into a single phase-only function. Simulation results show that the cross talks between multiplexed images have been significantly reduced, compared with prior methods [Opt. Lett.30, 1306 (2005); J. Opt. A8, 391 (2006)], thus presenting high promise in increasing the multiplexing capacity and encrypting grayscale and color images.
Reversible Data Hiding In Encrypted Images by Reserving Room before Encryption
Harish G, Smitha Shekar B, Prajwal R, Sunil S Shetty
2014-07-01
Full Text Available Recently, more and more attention is paid to reversible data hiding (RDH in encrypted images, since it maintains the excellent property that the original cover can be losslessly recovered after embedded data is extracted while protecting the image content’s conﬁdentiality. All previous methods embed data by reversibly vacating room from the encrypted images, which may subject to some errors on data extraction and/or image restoration. Here, a novel method is proposed so as to reserve room before encryption with a traditional RDH algorithm, and thus it is easy for the data hider to reversibly embed data in the encrypted image. The proposed method can achieve real reversibility, i.e., data extraction and image recovery are free of any error.
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
Chaotic Image Encryption with Random Shuffling of Data
Murat Aydos
2014-02-01
Full Text Available Security of valuable multimedia contents such as images in personal photograph albums, electronic publishing, frames of multicast video conference can be achieved by image encryption. Secure transmission of these contents is required to be rapid, efficient and practical. Hence, image encryption process must be chosen not only to satisfy the security goals but also to fulfill these requirements. Due to the inadequacy and inefficiency of conventional text based information encryption methods, researchers have proposed several encryption schemes. Many of them are based on chaotic algorithms. Recently, the studies are concentrated on some weaknesses of chaotic algorithms and most of the presented solutions came up with complex structured chaotic maps. In this paper, we present a self-diagonal shuffler mechanism embedded to one dimensional chaotic encryption system to overcome its leak points while keeping simplicity and efficiency properties.
Digital image encryption with chaotic map lattices
Sun Fu-Yan; Lü Zong-Wang
2011-01-01
This paper proposes a secure approach for encryption and decryption of digital images with chaotic map lattices.In the proposed encryption process, eight different types of operations are used to encrypt the pixels of an image and one of them will be used for particular pixels decided by the outcome of the chaotic map lattices. To make the cipher more robust against any attacks, the secret key is modified after encrypting each block of sixteen pixels of the image.The experimental results and security analysis show that the proposed image encryption scheme achieves high security and efficiency.
Image Encryption Algorithm Based on Chaotic Mappings%基于混沌映射的图像加密算法
卢辉斌; 肖霞
2011-01-01
This paper designs a new kind of image encryption algorithm which uses two Logistic systems. The auxiliary key m is obtained by a certain line data of the changed image matrix. The initial values of two Logistic mappings are modified by the key in. The Logistic mappings are used to generate the encryption sequences which are used to encrypt with every pixel of the image. Theoretical analysis and simulation results show the new algorithm not only has better sensitivity and very uniform pixel-value distribution, but also is simple and easy to achieve.%提出一种基于混沌映射的图像加密算法,该算法对图像进行拉伸融合折叠变换,通过映射其矩阵的某行数据,得到修改Logistic 映射初值的关键密钥m,并由2个Logistic混沌映射相结合产生加密序列,将图像与该序列进行相应代数运算,从而获得加密图像.理论分析和实验结果表明,该算法对密钥具有较强的敏感性,且加密图的像素值分布较均匀.
Sui, Liansheng; Liu, Benqing; Wang, Qiang; Li, Ye; Liang, Junli
2015-12-01
A color image encryption scheme is proposed based on Yang-Gu mixture amplitude-phase retrieval algorithm and two-coupled logistic map in gyrator transform domain. First, the color plaintext image is decomposed into red, green and blue components, which are scrambled individually by three random sequences generated by using the two-dimensional Sine logistic modulation map. Second, each scrambled component is encrypted into a real-valued function with stationary white noise distribution in the iterative amplitude-phase retrieval process in the gyrator transform domain, and then three obtained functions are considered as red, green and blue channels to form the color ciphertext image. Obviously, the ciphertext image is real-valued function and more convenient for storing and transmitting. In the encryption and decryption processes, the chaotic random phase mask generated based on logistic map is employed as the phase key, which means that only the initial values are used as private key and the cryptosystem has high convenience on key management. Meanwhile, the security of the cryptosystem is enhanced greatly because of high sensitivity of the private keys. Simulation results are presented to prove the security and robustness of the proposed scheme.
基于空域的图像加密算法与性能研究%Algorithm and performance of image encryption based on spatial domain
张晨
2015-01-01
In order to solve the problem of infringement of image information such as piracy and theft in information age, a method of image encryption based on spatial domain with excellent performance must be chosen to deal with it. This paper introduces the principle of algorithm of image encryption of Arnold transform scrambling, Logistic chaotic scrambling, Logistic chaotic sequence, Fibonacci sequence, and both Logistic chaotic scrambling and Logistic chaotic sequence and their performance, such as visual security of encrypted image, distortion of decrypted image, key space, key sensitivity, histogram, correlation between neighboring pixels, and entropy. After programming test, the analysis result of the experiments shows that the encryption method of both Logistic chaotic scrambling and Logistic chaotic sequence is the best one in comprehensive performance.%为解决信息时代中，图像信息的盗版、窃密等侵权问题，需要选择一种性能较好的基于空域的图像加密技术。文中介绍了Arnold变换置乱加密、Logistic混沌置乱加密、Logistic混沌序列加密、Fibonacci序列加密、Logistic混沌置乱与Logistic混沌序列混合加密的算法原理，以及如加密图像的视觉保密性、解密图像的失真度、密钥空间、密钥敏感性、直方图、邻域像素相关性、信息熵等性能指标。编程测试实验分析结果表明，Logistic混沌置乱与Logistic混沌序列混合加密是综合性能较为理想的加密方法。
Color image encryption based on Coupled Nonlinear Chaotic Map
Mazloom, Sahar [Faculty of Electrical, Computer and IT Engineering, Qazvin Islamic Azad University, Qazvin (Iran, Islamic Republic of)], E-mail: sahar.mazloom@gmail.com; Eftekhari-Moghadam, Amir Masud [Faculty of Electrical, Computer and IT Engineering, Qazvin Islamic Azad University, Qazvin (Iran, Islamic Republic of)], E-mail: eftekhari@qazviniau.ac.ir
2009-11-15
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.
Image Encryption based on the RGB PIXEL Transposition and Shuffling
Quist Aphetsi Kester
2013-06-01
Full Text Available Privacy is one of the key issues information Security addresses. Through encryption one can prevent a third party from understanding raw data during signal transmission. The encryption methods for enhancing the security of digital contents has gained high significance in the current era of breach of security and misuse of the confidential information intercepted and misused by the unauthorized parties. This paper sets out to contribute to the general body of knowledge in the area of cryptography application and by developing a cipher algorithm for image encryption of m*n size by shuffling the RGB pixel values. The algorithm ultimately makes it possible for encryption and decryption of the images based on the RGB pixel. The algorithm was implemented using MATLAB.
A fractal-based image encryption system
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.
Optical encryption for large-sized images
Sanpei, Takuho; Shimobaba, Tomoyoshi; Kakue, Takashi; Endo, Yutaka; Hirayama, Ryuji; Hiyama, Daisuke; Hasegawa, Satoki; Nagahama, Yuki; Sano, Marie; Oikawa, Minoru; Sugie, Takashige; Ito, Tomoyoshi
2016-02-01
We propose an optical encryption framework that can encrypt and decrypt large-sized images beyond the size of the encrypted image using our two methods: random phase-free method and scaled diffraction. In order to record the entire image information on the encrypted image, the large-sized images require the random phase to widely diffuse the object light over the encrypted image; however, the random phase gives rise to the speckle noise on the decrypted images, and it may be difficult to recognize the decrypted images. In order to reduce the speckle noise, we apply our random phase-free method to the framework. In addition, we employ scaled diffraction that calculates light propagation between planes with different sizes by changing the sampling rates.
PEA: Polymorphic Encryption Algorithm based on quantum computation
Komninos, N.; Mantas, G.
2011-01-01
In this paper, a polymorphic encryption algorithm (PEA), based on basic quantum computations, is proposed for the encryption of binary bits. PEA is a symmetric key encryption algorithm that applies different combinations of quantum gates to encrypt binary bits. PEA is also polymorphic since the states of the shared secret key control the different combinations of the ciphertext. It is shown that PEA achieves perfect secrecy and is resilient to eavesdropping and Trojan horse attacks. A securit...
Hardware Realization of Chaos Based Symmetric Image Encryption
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.
龙敏; 谭丽
2011-01-01
Using chaos-based weight variation of Huffman tree,an image/video encryption algorithm is proposed in this paper. In the process of the entropy coding,DC coefficients are encrypted by the weight variation of Huffman tree with the double Logistic chaos and AC coefficients are encrypted by the indexes of codeword. The security,complexity and compression ration of the algorithm are analyzed. Simulation results show that this algorithm has no impact on the compression efficiency and has low complexity,high security and good real-time property. Therefore,it is suitable for real-time image on the network.%提出一种采用混沌权值变异的Huff man树的图像加密算法.此算法在熵编码过程中,以基本的Huffman树为标准,利用双耦合混沌序列1对DC系数进行树的结构未变异、路径值变异的加密；再利用双耦合混沌序列2对AC系数进行码字序号的加密.论文对算法进行了仿真,并对安全性、计算复杂度、压缩比性能进行了分析.实验结果表明,该算法基本上不影响压缩效率,且计算复杂度低、安全性高和实时性好,可用于网络上的图像服务.
A new color image encryption scheme using CML and a fractional-order chaotic system.
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.
Asymmetric color image encryption based on singular value decomposition
Yao, Lili; Yuan, Caojin; Qiang, Junjie; Feng, Shaotong; Nie, Shouping
2017-02-01
A novel asymmetric color image encryption approach by using singular value decomposition (SVD) is proposed. The original color image is encrypted into a ciphertext shown as an indexed image by using the proposed method. The red, green and blue components of the color image are subsequently encoded into a complex function which is then separated into U, S and V parts by SVD. The data matrix of the ciphertext is obtained by multiplying orthogonal matrices U and V while implementing phase-truncation. Diagonal entries of the three diagonal matrices of the SVD results are abstracted and scrambling combined to construct the colormap of the ciphertext. Thus, the encrypted indexed image covers less space than the original image. For decryption, the original color image cannot be recovered without private keys which are obtained from phase-truncation and the orthogonality of V. Computer simulations are presented to evaluate the performance of the proposed algorithm. We also analyze the security of the proposed system.
Space-based optical image encryption.
Chen, Wen; Chen, Xudong
2010-12-20
In this paper, we propose a new method based on a three-dimensional (3D) space-based strategy for the optical image encryption. The two-dimensional (2D) processing of a plaintext in the conventional optical encryption methods is extended to a 3D space-based processing. Each pixel of the plaintext is considered as one particle in the proposed space-based optical image encryption, and the diffraction of all particles forms an object wave in the phase-shifting digital holography. The effectiveness and advantages of the proposed method are demonstrated by numerical results. The proposed method can provide a new optical encryption strategy instead of the conventional 2D processing, and may open up a new research perspective for the optical image encryption.
Priya Jambhulkar
2015-11-01
Full Text Available Digital image and information embedding system have number of important multimedia applications. Recently, attention is paid to reversible data hiding (RDH in encrypted images is more, since it maintains the excellent property that the original cover can be lossless recovered after embedded data is extracted while protecting the image content’s confidentiality. RDH is a technique used to hide data inside image for high security in such a way that original data is not visible. All previous methods embed data by reversibly vacating room from the encrypted images, which may be subject to some errors on data extraction and/or image restoration. In this paper, we propose another method in which we simply encrypt an image without its header by using our own algorithm. And thus it is easy for the data hider to reversibly embed data in the encrypted image. The proposed method can achieve real reversibility, that is, data extraction and image recovery are free of any error.
The Application Research of MD5 Encryption Algorithm in DCT Digital Watermarking
Xijin, Wang; Linxiu, Fan
This article did the preliminary study of the application of algorithm for MD5 in the digital watermark. It proposed that copyright information will be encrypted using an algorithm MD5, and made rules for the second value image watermarks, through DCT algorithm that embeds an image by the carrier. The extraction algorithms can pick up the watermark and restore MD5 code.
Cryptanalysis of "an improvement over an image encryption method based on total shuffling"
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.
Gray-scale and color optical encryption based on computational ghost imaging
Tanha, Mehrdad; Kheradmand, Reza; Ahmadi-Kandjani, Sohrab
2012-09-01
We propose two approaches for optical encryption based on computational ghost imaging. These methods have the capability of encoding ghost images reconstructed from gray-scale images and colored objects. We experimentally demonstrate our approaches under eavesdropping in two different setups, thereby proving the robustness and simplicity thereof for encryption compared with previous algorithms.
Association Algorithm of Encryption and Compression for Color Image%彩色图像加密与压缩关联算法
彭静玉; 赵鹤鸣
2014-01-01
针对传统的加密方法在彩色图像压缩方面的不足，提出一种用于保密通信的彩色图像加密与压缩关联算法。设计一个混合混沌系统在空域对秘密图像进行置乱。混沌系统产生针对彩色图像混淆变换的变换矩阵，改变载体图像的像素值。秘密图像每一像素的编码值与载体图像在设定区域中最佳像素点的坐标一一对应。最佳像素点按照最小欧氏距离的原则在载体图像的设定区域内搜索。经过压缩编码后的秘密图像数据不再是传统的像素值，而只是与序号或者下标对应的编码值。当压缩了67%的图像数据时，重构图像和原始图像的相似度仍然超过95%。对密钥空间、密钥的敏感性、加密图像的统计特性等加密效果进行仿真实验，结果表明，该算法安全性高、压缩率大，是一种有效的、易于实现的加密算法。%Aiming at the insufficiency of traditional encryption method in color image compression, a nassociation algorithm of color image encryption and compression is proposed for secure communication. A hybrid chaotic system is designed to scramble the secret image in time domain. Chaos system is also used to generate a transformation matrix for color images to confusion transform, which is used to change the carrier image pixels. Every pixel’s code value of secret image is one-to-one corresponded to the best pixel’s coordinates, which is searched in the carrier image’s setting area according to the principle of minimum Euclidean distance. After compression coding, the secret image data is no longer the traditional pixel value, but a group of code value corresponding the serial number or subscript. When 67 percent of the original image is compressed, the similarity between reconstructed image and original image is still more than 95%. The key space, sensitivity of the key and statistical features of encrypted image are also analyzed by simulation
Chaotic substitution for highly autocorrelated data in encryption algorithm
Anees, Amir; Siddiqui, Adil Masood; Ahmed, Fawad
2014-09-01
This paper addresses the major drawback of substitution-box in highly auto-correlated data and proposes a novel chaotic substitution technique for encryption algorithm to sort the problem. Simulation results reveal that the overall strength of the proposed technique for encryption is much stronger than most of the existing encryption techniques. Furthermore, few statistical security analyses have also been done to show the strength of anticipated algorithm.
Watermarking patient data in encrypted medical images
A Lavanya; V Natarajan
2012-12-01
In this paper, we propose a method for watermarking medical images for data integrity which consists of image encryption, data embedding and image-recovery phases. Data embedding can be completely recovered from the watermarked image after the watermark has been extracted. In the proposed method, we utilize standard stream cipher for image encryption and selecting non-region of interest tile to embed patient data. We show that the lower bound of the PSNR (peak-signal-to-noise-ratio) values for medical images is about 48 dB. Experimental results demonstrate that the proposed scheme can embed a large amount of data while keeping high visual quality of test images.
Image compression-encryption scheme based on hyper-chaotic system and 2D compressive sensing
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.
Double-image encryption based on discrete fractional random transform and chaotic maps
Li, Huijuan; Wang, Yurong
2011-07-01
A novel double-image encryption algorithm is proposed, based on discrete fractional random transform and chaotic maps. The random matrices used in the discrete fractional random transform are generated by using a chaotic map. One of the two original images is scrambled by using another chaotic map, and then encoded into the phase of a complex matrix with the other original image as its amplitude. Then this complex matrix is encrypted by the discrete fractional random transform. By applying the correct keys which consist of initial values, control parameters, and truncated positions of the chaotic maps, and fractional orders, the two original images can be recovered without cross-talk. Numerical simulation has been performed to test the validity and the security of the proposed encryption algorithm. Encrypting two images together by this algorithm creates only one encrypted image, whereas other single-image encryption methods create two encrypted images. Furthermore, this algorithm requires neither the use of phase keys nor the use of matrix keys. In this sense, this algorithm can raise the efficiency when encrypting, storing or transmitting.
A novel color image encryption scheme using alternate chaotic mapping structure
Wang, Xingyuan; Zhao, Yuanyuan; Zhang, Huili; Guo, Kang
2016-07-01
This paper proposes an color image encryption algorithm using alternate chaotic mapping structure. Initially, we use the R, G and B components to form a matrix. Then one-dimension logistic and two-dimension logistic mapping is used to generate a chaotic matrix, then iterate two chaotic mappings alternately to permute the matrix. For every iteration, XOR operation is adopted to encrypt plain-image matrix, then make further transformation to diffuse the matrix. At last, the encrypted color image is obtained from the confused matrix. Theoretical analysis and experimental results has proved the cryptosystem is secure and practical, and it is suitable for encrypting color images.
Image encryption based on Independent Component Analysis and Arnold’s Cat Map
Nidaa AbdulMohsin Abbas
2016-03-01
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, a new efficient image encryption technique is presented. It is based on modifying the mixing matrix in Independent Component Analysis (ICA using the chaotic Arnold’s Cat Map (ACM for encryption. First, the mixing matrix is generated from the ACM by insert square image of any dimension. Second, the mixing process is implemented using the mixing matrix and the image sources the result is the encryption images that depend on the number of sources. Third, images decrypted using ICA algorithms. We use the Joint Approximate Diagonalization of Eigen-matrices (JADE algorithm as a case study. The results of several experiments, PSNR, SDR and SSIM index tests compared with standard mixing matrix showed that the proposed image encryption system provided effective and safe way for image encryption.
Chen, Wen; Chen, Xudong; Sheppard, Colin J R
2012-02-13
We propose a new method using coherent diffractive imaging for optical color-image encryption and synthesis in the Fresnel domain. An optical multiple-random-phase-mask encryption system is applied, and a strategy based on lateral translations of a phase-only mask is employed during image encryption. For the decryption, an iterative phase retrieval algorithm is applied to extract high-quality decrypted color images from diffraction intensity maps (i.e., ciphertexts). In addition, optical color-image synthesis is also investigated based on coherent diffractive imaging. Numerical results are presented to demonstrate feasibility and effectiveness of the proposed method. Compared with conventional interference methods, coherent diffractive imaging approach may open up a new research perspective or can provide an effective alternative for optical color-image encryption and synthesis.
Double Layer Image Security System using Encryption and Steganography
Samreen Sekhon Brar
2016-03-01
Full Text Available The image security on internet transfers is the concern of the hour as the breaching attacks into the image databases are rising every year. The hackers take advantage of the stolen personal and important images to fulfill their dangerous and unethical intentions. The image data theft can be used to defame a person on the internet by posting the illegal and unacceptable images of that person (internet user. Hence the images transfers have to be secure to ensure the privacy of the user's image data. In this research, a number of image security systems have been studied to evaluate the research gap. Majority of the existing image security systems are not up to date to protect against the latest breaching attacks. So, we have proposed an effective and robust image security framework particularly designed for the images. The proposed has been designed and implemented using MATLAB. In this research, a hybrid image security framework has been proposed to overcome the problem stated earlier, which will be implemented by combining various techniques together to achieve the image security goal. The techniques included in the combination would beimage compression, cryptography andsteganography. DWT compression has been used, because it is a stronger compression algorithm. The steganographed image would be compressed to reduce its size. Blowfish encryption algorithm would be used for the encryption purposes. It offers maximum throughput (faster and also energy efficient. Compressed image would be encrypted to enhance the image security. Real image will be hidden into another image. A cluster based steganographic technique will be used. Real image and face image would be analyzed, and the real image would be embedded in those areas of face image, where color schemes of the real image and face image would be most similar. Kmeans or Hierarchical clustering would be used as a clustering technique. An all new comparative analysis technique would be applied to
New image encryption algorithm of extended logistic equation%一种改进logistic方程的图像加密新算法
蒋梦轩; 射可夫
2012-01-01
提出了改进的logistic混沌方程和新的图像加密算法.改进的混沌方程对比logistic混沌方程具有更大的密钥空间,而且所生成的混沌序列的互相关性、敏感性等密码特性更好.新的图像加密算法是运用密码学原理设计的随机加密算法,理论上安全空间非常大.理论分析和计算机仿真实验表明该方程和该算法结合的加密机制具有更好的加密效果和安全性,能有效抵抗暴力攻击、已知明文攻击和统计分析.%An extended logistic equation and new image encryption algorithm is proposed. Compared with the logistic equation, the improved chaotic equation has larger key space, and the generated chaotic sequences has excellent performance such as cross correlation and sensitivity. The algorithm is designed based on cryptography theory and safety space is huge. Theoretical analyses and computer simulation show that the equation and the algorithm has more efficiency and security, it can resist violence attack, known-plaintext attack and statistical analysis effectively.
SIT: A Lightweight Encryption Algorithm for Secure Internet of Things
Muhammad Usman
2017-01-01
Full Text Available The Internet of Things (IoT being a promising technology of the future is expected to connect billions of devices. The increased number of communication is expected to generate mountains of data and the security of data can be a threat. The devices in the architecture are essentially smaller in size and low powered. Conventional encryption algorithms are generally computationally expensive due to their complexity and requires many rounds to encrypt, essentially wasting the constrained energy of the gadgets. Less complex algorithm, however, may compromise the desired integrity. In this paper we propose a lightweight encryption algorithm named as Secure IoT (SIT. It is a 64-bit block cipher and requires 64-bit key to encrypt the data. The architecture of the algorithm is a mixture of feistel and a uniform substitution-permutation network. Simulations result shows the algorithm provides substantial security in just five encryption rounds. The hardware implementation of the algorithm is done on a low cost 8-bit micro-controller and the results of code size, memory utilization and encryption/decryption execution cycles are compared with benchmark encryption algo-rithms. The MATLAB code for relevant simulations is available online at https://goo.gl/Uw7E0W.
Multiple Encryption-based Algorithm of Agricultural Product Trace Code
2012-01-01
To establish a sound traceability system of agricultural products and guarantee security of agricultural products,an algorithm is proposed to encrypt trace code of agricultural products.Original trace code consists of 34 digits indicating such information as place of origin,name of product,date of production and authentication.Area code is used to indicate enterprise information,the encrypted algorithm is designed because of the increasing code length,such coding algorithms as system conversion and section division are applied for the encrypted conversion of code of origin place and production date code,moreover,section identification code and authentication code are permutated and combined to produce check code.Through the multiple encryption and code length compression,34 digits are compressed to 20 on the basis of ensuring complete coding information,shorter code length and better encryption enable the public to know information about agricultural products without consulting professional database.
Chaos-Based Encryption Algorithm for Compressed Video
袁春; 钟玉琢; 贺玉文
2003-01-01
Encryption for compressed video streams has attracted increasing attention with the exponential growth of digital multimedia delivery and consumption. However, most algorithms proposed in the literature do not effectively address the peculiarities of security and performance requirements. This paper presents a chaos-based encryption algorithm called the chaotic selective encryption of compressed video (CSECV) which exploits the characteristics of the compressed video. The encryption has three separate layers that can be selected according to the security needs of the application and the processing capability of the client computer. The chaotic pseudo-random sequence generator used to generate the key-sequence to randomize the important fields in the compressed video stream has its parameters encrypted by an asymmetric cipher and placed into the stream. The resulting stream is still a valid video stream. CSECV has significant advantages over existing algorithms for security, decryption speed, implementation flexibility, and error preservation.
Optical encryption with selective computational ghost imaging
Zafari, Mohammad; kheradmand, Reza; Ahmadi-Kandjani, Sohrab
2014-10-01
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.
Interference-based multiple-image encryption with silhouette removal by position multiplexing.
Qin, Yi; Gong, Qiong
2013-06-10
An approach for multiple-image encryption based on interference and position multiplexing is proposed. In the encryption process, multiple images are analytically hidden into three phase-only masks (POMs). The encryption algorithm for this method is quite simple and does not need iterative encoding. For decryption, both the digital method and optical method could be employed. Also, we analyze the multiplexing capacity through the correlation coefficient. In addition, the silhouette problem that exists in previous interference-based encryption methods with two POMs can be eliminated during the generation procedure of POMs based on the interference principle. Simulation results are presented to verify the validity of the proposed approach.
Design And Implementation Of Tiny Encryption Algorithm
Kiran Kumar.V.G
2015-06-01
Full Text Available Over the recent years, several smart applications like RFID‟s, sensor networks, including industrial systems, critical infrastructures, private and public spaces as well as portable and wearable applications in which highly constrained devices are interconnected, typically communicating wirelessly with one another, working in concert to accomplish some task. Advanced safety and security mechanisms can be very important in all of these areas. Light weight cryptography enables secure and efficient communication between networked smart objects. This proposed system focuses on the FPGA implementation of light weight cryptographic algorithm Tiny Encryption Algorithm TEA to adapt with many real time constraints such as memory, data loss and low cost. The proposed scheme uses Linear Feedback Shift Register to generate the random key making it more secure for sensitive information transfer in many real-time applications. In this study,operation of this cryptosystem is analyzed by implementing the cryptographic algorithm TEA with the key generation unit in FPGA Spartan 3E. We have also compared the results with the IDEA.
Encryption of color images using MSVD in DCST domain
Kumar, Manoj; Vaish, Ankita
2017-01-01
In this paper, a new image encryption and decryption algorithm based on Multiresolution Singular Value Decomposition (MSVD) and Discrete Cosine Stockwell Transform (DCST) is proposed. An original image is first transformed in DCST domain and then decomposed into four subbands using MSVD, all the four subbands are further decomposed into four subimages according to their indexing and masked by the parameters generated by MSVD. We have used number of bands of DCST, arrangement of MSVD subbands, arrangement of various subimages obtained from MSVD subbands, values and arrangement of a 4×4 matrix generated by MSVD and the arrangement of masked subimages as encryption and decryption keys. To ensure the correct decryption of encrypted image, it is indeed necessary to have correct knowledge of all keys in correct order along with their exact values. If all the keys are correct but a single key is wrong even though it would be almost impossible to guess the original image. The efficiency of proposed algorithm is evaluated by comparing it with some recent published works and it is evident from the experimental results and analysis that the proposed algorithm can transmit the images more securely and efficiently over the network.
Multiple Lookup Table-Based AES Encryption Algorithm Implementation
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.
Classification of Novel Selected Region of Interest for Color Image Encryption
Lahieb Mohammed Jawad
2015-04-01
Full Text Available Securing digital image in exchanging huge multimedia data over internet with limited bandwidth is a significant and sensitive issue. Selective image encryption being an effective method for reducing the amount of encrypted data can achieve adequate security enhancement. Determining and selecting the region of interest in digital color images is challenging for selective image encryption due to their complex structure and distinct regions of varying importance. We propose a new feature in acquiring and selecting Region of Interest (ROI for the color images to develop a selective encryption scheme. The hybrid domain is used to encrypt regions based on chaotic map approach which automatically generates secret key. This new attribute is a vitality facet representing the noteworthy part of the color image. The security performance of selective image encryption is found to enhance considerably based on the rates of encrypted area selection. Computation is performed using MATLAB R2008a codes on eight images (Lena, Pepper, Splash, Airplane, House, Tiffany, Baboon and Sailboat each of size 512*512 pixels obtained from standard USC-SIPI Image Database. A block size of 128*128 pixels with threshold levels 0.0017 and 0.48 are employed. Results are analyzed and compared with edge detection method using the same algorithm. Encrypted area, entropy and correlation coefficients performances reveal that the proposed scheme achieves good alternative in the confined region of interest, fulfills the desired confidentiality and protects image privacy.
An asymmetric color image encryption method by using deduced gyrator transform
Yao, Lili; Yuan, Caojin; Qiang, Junjie; Feng, Shaotong; Nie, Shouping
2017-02-01
An encryption algorithm is proposed by using the properties of deduced gyrator transform (GT). After being transformed by the GT algorithm and multiplied by a phase distribution p*, the spectrum modulus of the input image is considered to be the encrypted image by further performing Fourier transformation. To resist the attack from iterative phase retrieval, the red, green and blue components of the input image is modulated by a random phase mask and then combined using convolution. The encryption result is real-valued, which is convenient for display, transmission and storage. In the decryption process, the three original color components can be recovered with decryption keys which are different from the encryption keys. An optoelectronic hybrid system for the encryption process is also presented. Computer simulations are presented to demonstrate its performance, and the security of the proposed system is analyzed as well.
基于量子Logistic映射的小波域图像加密算法%Image Encryption Algorithm Based on Quantum Logistic Map in Wavelet Domain
罗玉玲; 杜明辉
2013-01-01
为增强图像加密算法的安全性和高效性,基于量子Logistic混沌映射和二维离散小波变换,提出了一种结合置乱与扩散的自适应图像加密算法.首先,对图像进行离散小波分解,利用量子Logistic映射产生的随机序列对分解得到的低频子带系数进行排序,对改变后的小波系数分布结构做小波反变换,得到置乱图像；然后,提取新的混沌序列,逐一替换置乱图像的像素,与此同时扰动量子混沌系统完成像素的自适应替换,从而达到更好的扩散效果.实验结果与性能分析表明,该图像加密算法具有密钥空间大、安全性高和运算速度快等特点,并且加密图像灰度值的分布具有类随机的行为.%In order to improve the safety and efficiency of image encryption algorithms,a new adaptive algorithm based on quantum Logistic map and 2D discrete wavelet transform (DWT),which combines confusion and diffusion,is proposed.In this algorithm,first,the original image is decomposed into low-pass subband and high-pass subband coefficients via the DWT,and the low-pass ones are sorted out by using the quantum Logistic map with random sequences,followed by an inverse DWT to obtain a shuffled image.Then,each pixel of the shuffled image is mixed with the chaotic sequence generated by the quantum Logistic system,and the quantum Logistic system is perturbed to substitute for pixel values adaptively.Thus,better diffusion effect is achieved.Experimental results and performance analysis demonstrate that the proposed algorithm is of large key space,high security and high operation speed,etc.,and that it helps to obtain cipher images with random gray distribution.
基于五维混沌系统的图像加密研究%Five-dimensional chaotic system based image encryption algorithm
高亮; 朱博; 孙鸣; 朱建良
2011-01-01
随着计算机技术、信息技术和通讯技术等高科技技术在近年来的迅猛发展,信息加密越来越受到人们的重视,提出了基于五维混沌系统用来实现图像加密的方法,并利用迭代次数和方式作为密码,实现了图像加密和解密,为信息加密提供了一种新方法.%With computer technology, information technology and communications technology, high technology, rapid development in recent years, more and more people pay close attention to information encryption. This paper, based on five-dimensional chaotic system realizes image encryption method, and means of using the number of iterations as the password, to realize the image encryption and decryption,the information provides a new method of encryption.
Overview on Selective Encryption of Image and Video: Challenges and Perspectives
Massoudi A
2008-01-01
Full Text Available 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, AES, IDEA, etc.. The specific characteristics of this kind of data (high-transmission rate with limited bandwidth make standard encryption algorithms inadequate. Another limitation of fully layered systems consists of altering the whole bitstream syntax which may disable some codec functionalities. Selective encryption is a new trend in image and video content protection. It consists of encrypting only a subset of the data. The aim of selective encryption is to reduce the amount of data to encrypt while preserving a sufficient level of security. This computation saving is very desirable especially in constrained communications (real-time networking, high-definition delivery, and mobile communications with limited computational power devices. In addition, selective encryption allows preserving some codec functionalities such as scalability. This tutorial is intended to give an overview on selective encryption algorithms. The theoretical background of selective encryption, potential applications, challenges, and perspectives is presented.
Liang, Yaru; Liu, Guoping; Zhou, Nanrun; Wu, Jianhua
2015-02-01
Based on the fractional discrete cosine transform with multiple generating sequences (MGSFrDCT) and the dependent scrambling and diffusion (DSD), an image encryption algorithm is proposed, in which the multiple-generating sequences greatly enlarge the key space of the encryption system. The real-valued output of MGSFrDCT is beneficial to storage, display and transmission of the cipher-text. During the stage of confusion and diffusion, the locations and values of all MGSFrDCT transformed coefficients change due to DSD, and the initial values and fractional orders of encryption system depend not only on the cipher keys but also on the plain-image due to introduction of a disturbance factor, which allows the encryption system to resist the known-plaintext and chosen-plaintext attacks. Experimental results demonstrate that the proposed encryption algorithm is feasible, effective and secure and able to resist common classical attacks.
Double image encryption by using iterative random binary encoding in gyrator domains.
Liu, Zhengjun; Guo, Qing; Xu, Lie; Ahmad, Muhammad Ashfaq; Liu, Shutian
2010-05-24
We propose a double image encryption by using random binary encoding and gyrator transform. Two secret images are first regarded as the real part and imaginary part of complex function. Chaotic map is used for obtaining random binary matrix. The real part and imaginary part of complex function are exchanged under the control of random binary data. An iterative structure composed of the random binary encoding method is designed and employed for enhancing the security of encryption algorithm. The parameters in chaotic map and gyrator transform serve as the keys of this encryption scheme. Some numerical simulations have been made, to demonstrate the performance this algorithm.
Parallel Algorithm for Wireless Data Compression and Encryption
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.
A Parallel Encryption Algorithm Based on Piecewise Linear Chaotic Map
Xizhong Wang
2013-01-01
Full Text Available We introduce a parallel chaos-based encryption algorithm for taking advantage of multicore processors. The chaotic cryptosystem is generated by the piecewise linear chaotic map (PWLCM. The parallel algorithm is designed with a master/slave communication model with the Message Passing Interface (MPI. The algorithm is suitable not only for multicore processors but also for the single-processor architecture. The experimental results show that the chaos-based cryptosystem possesses good statistical properties. The parallel algorithm provides much better performance than the serial ones and would be useful to apply in encryption/decryption file with large size or multimedia.
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.
Symmetric encryption algorithms using chaotic and non-chaotic generators: A review.
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.
Cryptanalysis of the Two-Dimensional Circulation Encryption Algorithm
Bart Preneel
2005-07-01
Full Text Available We analyze the security of the two-dimensional circulation encryption algorithm (TDCEA, recently published by Chen et al. in this journal. We show that there are several flaws in the algorithm and describe some attacks. We also address performance issues in current cryptographic designs.
Optical image encryption based on compressive sensing and chaos in the fractional Fourier domain
Liu, Xingbin; Mei, Wenbo; Du, Huiqian
2014-11-01
We propose a novel image encryption algorithm based on compressive sensing (CS) and chaos in the fractional Fourier domain. The original image is dimensionality reduction measured using CS. The measured values are then encrypted using chaotic-based double-random-phase encoding technique in the fractional Fourier transform domain. The measurement matrix and the random-phase masks used in the encryption process are formed from pseudo-random sequences generated by the chaotic map. In this proposed algorithm, the final result is compressed and encrypted. The proposed cryptosystem decreases the volume of data to be transmitted and simplifies the keys for distribution simultaneously. Numerical experiments verify the validity and security of the proposed algorithm.
Chaotic Image Encryption with Random Shuffling of Data
Aydos, Murat; Uğur, Alper
2014-01-01
Security of valuable multimedia contents such as images in personal photograph albums, electronic publishing, frames of multicast video conference can be achieved by image encryption. Secure transmission of these contents is required to be rapid, efficient and practical. Hence, image encryption process must be chosen not only to satisfy the security goals but also to fulfill these requirements. Due to the inadequacy and inefficiency of conventional text based information encryption methods, r...
AN ENCRYPTION ALGORITHM FOR IMPROVING DATABASE SECURITY USING ROT & REA
M. Sujitha
2015-06-01
Full Text Available Database is an organized collection of data, many user wants to store their personal and confidential data’s in such database. Unauthorized persons may try to get the data’s from database and misuse them without the owner’s knowledge. To overcome such problem the advanced control mechanism, known as Database security was introduced. Encryption algorithm is one of the way to give protection to the database from various threat or hackers who target to get confidential information. This paper discuss about the proposed encryption algorithm to give security to such database.
Bondareva, Alyona P.; Cheremkhin, Pavel A.; Evtikhiev, Nikolay N.; Krasnov, Vitaly V.; Rodin, Vladislav G.; Starikov, Sergey N.
2014-10-01
At present time methods of optical encryption are actively developed. The majority of existing methods of optical encryption use not only light intensity distribution, easily registered with photosensors, but also its phase distribution which require application of complex holographic schemes in conjunction with spatially coherent monochromatic illumination. This leads to complex optical schemes and low decryption quality. To eliminate these disadvantages it is possible to implement optical encryption using spatially incoherent monochromatic illumination which requires registration of light intensity distribution only. Encryption is accomplished by means of optical convolution of image of scene to be encrypted and encryption diffractive optical element (DOE) point spread function (PSF) which serves as encryption key. Encryption process is described as follows. Scene is illuminated with spatially-incoherent monochromatic light. In the absence of encryption DOE lens forms image of scene in photosensor plane. DOE serves as encryption element, its PSF - encryption key. Light passing through DOE forms convolution of object image and DOE PSF. Registered by photosensor convolution is encrypted image. Decryption was conducted numerically on computer by means of inverse filtration with regularization. Kinoforms were used as encryption DOE because they have single diffraction order. Two liquid crystal (LC) spatial light modulators (SLM) were used to implement dynamic digital information input and dynamic encryption key change. As input scene amplitude LC SLM HoloEye LC2002 with 800×600 pixels 32×32 μm2 and 256 gray levels was used. To image synthesized encryption kinoforms phase LC SLM HoloEye PLUTO VIS with 1920×1080 pixels 8×8 μm2 and 256 phase levels was used. Set of test images was successfully optically encrypted and then numerically decrypted. Encrypted images contents are hidden. Decrypted images despite quite high noise levels are positively recognizable
Digital Image Encryption Based On Multiple Chaotic Maps
Amir Houshang Arab Avval
2016-01-01
Full Text Available A novel and robust chaos-based digital image encryption is proposed. The present paper presents a cipher block image encryption using multiple chaotic maps to lead increased security. An image block is encrypted by the block-based permutation process and cipher block encryption process. In the proposed scheme, secret key includes nineteen control and initial conditions parameter of the four chaotic maps and the calculated key space is 2883. The effectiveness and security of the proposed encryption scheme has been performed using the histograms, correlation coefficients, information entropy, differential analysis, key space analysis, etc. It can be concluded that the proposed image encryption technique is a suitable choice for practical applications.
Single-random-phase holographic encryption of images
Tsang, P. W. M.
2017-02-01
In this paper, a method is proposed for encrypting an optical image onto a phase-only hologram, utilizing a single random phase mask as the private encryption key. The encryption process can be divided into 3 stages. First the source image to be encrypted is scaled in size, and pasted onto an arbitrary position in a larger global image. The remaining areas of the global image that are not occupied by the source image could be filled with randomly generated contents. As such, the global image as a whole is very different from the source image, but at the same time the visual quality of the source image is preserved. Second, a digital Fresnel hologram is generated from the new image, and converted into a phase-only hologram based on bi-directional error diffusion. In the final stage, a fixed random phase mask is added to the phase-only hologram as the private encryption key. In the decryption process, the global image together with the source image it contained, can be reconstructed from the phase-only hologram if it is overlaid with the correct decryption key. The proposed method is highly resistant to different forms of Plain-Text-Attacks, which are commonly used to deduce the encryption key in existing holographic encryption process. In addition, both the encryption and the decryption processes are simple and easy to implement.
ENCRYPTION TECHNIQUES FOR SECURITY OF IMAGES
DR. DHIRENDRA MISHRA
2014-01-01
Full Text Available With the proliferation in technology and advent of internet the data has been digitized, so more emphasis is required for security while transmission and storage to save from unauthorized users. Protecting data in a safe and secure way which does not hamper the access of an authorized authority is difficult and interesting research problem. Many attempts have been made to solve this problem within the cryptographic community. Visual cryptography provides a very powerful technique by which one secret can be distributed into two or more images known as shares. When the shares on transparencies are superimposed exactly together, original secret can be discovered without computer involvement. Image cryptography disrupts the image so that no useful information is seen. The keys used for disruption is used in reverse manner to decrypt the image. This paper discusses the various encryption techniques for better image security and to protect them from unintentional user.
A novel chaos-based bit-level permutation scheme for digital image encryption
Fu, Chong; Lin, Bin-bin; Miao, Yu-sheng; Liu, Xiao; Chen, Jun-jie
2011-11-01
Confidentiality is an important issue when digital images are transmitted over public networks, and encryption is the most useful technique employed for this purpose. 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 algorithms. Recently, chaos-based encryption has suggested a new and efficient way to deal with the intractable problems of fast and highly secure image encryption. This paper proposes a novel chaos-based bit-level permutation scheme for secure and efficient image cipher. To overcome the drawbacks of conventional permutation-only type image cipher, the proposed scheme introduced a significant diffusion effect in permutation procedure through a two-stage bit-level shuffling algorithm. The two-stage permutation operations are realized by chaotic sequence sorting algorithm and Arnold Cat map, respectively. Results of various types of analysis are interesting and indicate that the security level of the new scheme is competitive with that of permutation-diffusion type image cipher, while the computational complexity is much lower. Therefore the new scheme is a good candidate for real-time secure image communication applications.
A joint encryption/watermarking system for verifying the reliability of medical images.
Bouslimi, Dalel; Coatrieux, Gouenou; Cozic, Michel; Roux, Christian
2012-09-01
In this paper, we propose a joint encryption/water-marking system for the purpose of protecting medical images. This system is based on an approach which combines a substitutive watermarking algorithm, the quantization index modulation, with an encryption algorithm: a stream cipher algorithm (e.g., the RC4) or a block cipher algorithm (e.g., the AES in cipher block chaining (CBC) mode of operation). Our objective is to give access to the outcomes of the image integrity and of its origin even though the image is stored encrypted. If watermarking and encryption are conducted jointly at the protection stage, watermark extraction and decryption can be applied independently. The security analysis of our scheme and experimental results achieved on 8-bit depth ultrasound images as well as on 16-bit encoded positron emission tomography images demonstrate the capability of our system to securely make available security attributes in both spatial and encrypted domains while minimizing image distortion. Furthermore, by making use of the AES block cipher in CBC mode, the proposed system is compliant with or transparent to the DICOM standard.
Dual Key Speech Encryption Algorithm Based Underdetermined BSS
Huan Zhao
2014-01-01
Full Text Available When the number of the mixed signals is less than that of the source signals, the underdetermined blind source separation (BSS is a significant difficult problem. Due to the fact that the great amount data of speech communications and real-time communication has been required, we utilize the intractability of the underdetermined BSS problem to present a dual key speech encryption method. The original speech is mixed with dual key signals which consist of random key signals (one-time pad generated by secret seed and chaotic signals generated from chaotic system. In the decryption process, approximate calculation is used to recover the original speech signals. The proposed algorithm for speech signals encryption can resist traditional attacks against the encryption system, and owing to approximate calculation, decryption becomes faster and more accurate. It is demonstrated that the proposed method has high level of security and can recover the original signals quickly and efficiently yet maintaining excellent audio quality.
Dual key speech encryption algorithm based underdetermined BSS.
Zhao, Huan; He, Shaofang; Chen, Zuo; Zhang, Xixiang
2014-01-01
When the number of the mixed signals is less than that of the source signals, the underdetermined blind source separation (BSS) is a significant difficult problem. Due to the fact that the great amount data of speech communications and real-time communication has been required, we utilize the intractability of the underdetermined BSS problem to present a dual key speech encryption method. The original speech is mixed with dual key signals which consist of random key signals (one-time pad) generated by secret seed and chaotic signals generated from chaotic system. In the decryption process, approximate calculation is used to recover the original speech signals. The proposed algorithm for speech signals encryption can resist traditional attacks against the encryption system, and owing to approximate calculation, decryption becomes faster and more accurate. It is demonstrated that the proposed method has high level of security and can recover the original signals quickly and efficiently yet maintaining excellent audio quality.
底晓强; 母一宁; 李锦青; 杨华民
2014-01-01
Since chaos is sensitive for initial values, it is very suitable for data encryption. An image encryption algorithm based on hyper- chaotic control parameters and mixed scrambling diffusion structure of higher- order chaotic system was presented. The encryption algorithm included scrambling step and diffusion step. In the scrambling step, the composite chaotic map was used to generate the alignment phase control parameters and scramble for the high- level image cross- correlation between the adjacent pixels. In the diffusion step, the composite chaotic map with the different initial states and parameters was used to generate the initial conditions for hyper- chaotic cellular neural networks in order to generate the key stream. This method was evaluated by known plaintext attack and chosen plaintext attack, key space, image histogram, and simulations show good results. Compared with several other related algorithms, it has better anti- aggressive and key sensitivity is high. It can be applied to the image encryption.%混沌对初值敏感的特性使得它适合于数据加密。以4阶CNN模型为基础，提出了一种新的超混沌细胞神经网络图像加密算法。算法分为置乱和扩散二个阶段，复合混沌映射用于生成置乱阶段控制参数，用以置乱图像行列之间的高度互相关像素。在扩散阶段，使用不同初始状态和参数的复合混沌映射生成高阶混沌细胞神经网络的初始条件，以生成扩散阶段的密钥流。算法的已知明文和选择明文攻击、密钥空间和直方图的仿真实验均取得了良好的结果。与其他相关算法相比，该算法具有密钥敏感性和抗攻击性强的优点，适用于图像加密。
Shannon Entropy based Randomness Measurement and Test for Image Encryption
Wu, Yue; Agaian, Sos
2011-01-01
The quality of image encryption is commonly measured by the Shannon entropy over the ciphertext image. However, this measurement does not consider to the randomness of local image blocks and is inappropriate for scrambling based image encryption methods. In this paper, a new information entropy-based randomness measurement for image encryption is introduced which, for the first time, answers the question of whether a given ciphertext image is sufficiently random-like. It measures the randomness over the ciphertext in a fairer way by calculating the averaged entropy of a series of small image blocks within the entire test image. In order to fulfill both quantitative and qualitative measurement, the expectation and the variance of this averaged block entropy for a true-random image are strictly derived and corresponding numerical reference tables are also provided. Moreover, a hypothesis test at significance?-level is given to help accept or reject the hypothesis that the test image is ideally encrypted/random-...
Encrypting three-dimensional information system based on integral imaging and multiple chaotic maps
Xing, Yan; Wang, Qiong-Hua; Xiong, Zhao-Long; Deng, Huan
2016-02-01
An encrypting three-dimensional (3-D) information system based on integral imaging (II) and multiple chaotic maps is proposed. In the encrypting process, the elemental image array (EIA) which represents spatial and angular information of the real 3-D scene is picked up by a microlens array. Subsequently, R, G, and B color components decomposed by the EIA are encrypted using multiple chaotic maps. Finally, these three encrypted components are interwoven to obtain the cipher information. The decryption process implements the reverse operation of the encryption process for retrieving the high-quality 3-D images. Since the encrypted EIA has the data redundancy property due to II, and all parameters of the pickup part are the secret keys of the encrypting system, the system sensitivity on the changes of the plaintext and secret keys can be significantly improved. Moreover, the algorithm based on multiple chaotic maps can effectively enhance the security. A preliminary experiment is carried out, and the experimental results verify the effectiveness, robustness, and security of the proposed system.
Control of Chaotic Regimes in Encryption Algorithm Based on Dynamic Chaos
Sidorenko, V.; Mulyarchik, K. S.
2013-01-01
Chaotic regime of a dynamic system is a necessary condition determining cryptographic security of an encryption algorithm. A chaotic dynamic regime control method is proposed which uses parameters of nonlinear dynamics regime for an analysis of encrypted data.
安全的LZW编码算法及其在GIF图像加密中的应用%Secure LZW coding algorithm and its application in GIF image encryption
向涛; 王安
2012-01-01
This paper proposed a Secure LZW (SLZW) coding algorithm, where encryption was embedded into the improved LZW coding process, and SLZW can fulfill compression and encryption in a single step. In SLZW algorithm, dynamic Huffman tree was utilized to code the dictionary of LZW, and the initialization and updating of Huffman tree were controlled by a sequence of keystream generated by Coupled Map Lattcie (CML). The code words were further XORed with the keystream to generate the ciphertext. The SLZW was applied to GIF image encryption. The experimental results and their analyses indicate that the proposed SLZW algorithm not only has good security, but can also improves the compression ratio by about 10% . Therefore, SLZW can find its wide applications in practice.%提出了一种安全的LZW编码算法——SLZW.该算法在改进的LZW编码过程中嵌入加密,从而能够同时完成压缩和加密.SLZW编码利用动态Huffman树作为LZW的字典,并且通过耦合映像格子(CML)产生的密钥流对字典的构建和更新进行控制,编码输出进一步和密钥流进行异或后产生密文.并且,该算法被应用于GIF图像加密中,实验结果和分析表明,该算法不仅具有较好的安全性,同时也将标准LZW算法的压缩效率提高了10％左右,具有广泛的实用性.
Reducing Computational Time of Basic Encryption and Authentication Algorithms
Sandeep Kumar,
2011-04-01
Full Text Available Today most of data are sending via the internet for sharing, so the trust of data files is decreased. For the trust more security and authentication is needed, less security increase the liability ofattacks on data. Digital signature of the data is a solution to this security problem which provides the reliability, authenticity and accuracy. Most basic algorithm for security and authentication is RSA, DSA, algorithms which uses the different key of different sizes. This work presents ECDSA algorithm to encrypt the data, use parameterized hash algorithm to authenticate the data and also compare both RSA and ECDSA methods in respect of time parameters.
A Secure Network Communication Protocol Based on Text to Barcode Encryption Algorithm
Abusukhon Ahmad
2015-12-01
Full Text Available Nowadays, after the significant development in the Internet, communication and information exchange around the world has become easier and faster than before. One may send an e-mail or perform money transaction (using a credit card while being at home. The Internet users can also share resources (storage, memory, etc. or invoke a method on a remote machine. All these activities require securing data while the data are sent through the global network. There are various methods for securing data on the internet and ensuring its privacy; one of these methods is data encryption. This technique is used to protect the data from hackers by scrambling these data into a non-readable form. In this paper, we propose a novel method for data encryption based on the transformation of a text message into a barcode image. In this paper, the proposed Bar Code Encryption Algorithm (BCEA is tested and analyzed.
Optical color-image encryption in the diffractive-imaging scheme
Qin, Yi; Wang, Zhipeng; Pan, Qunna; Gong, Qiong
2016-02-01
By introducing the theta modulation technique into the diffractive-imaging-based optical scheme, we propose a novel approach for color image encryption. For encryption, a color image is divided into three channels, i.e., red, green and blue, and thereafter these components are appended by redundant data before being sent to the encryption scheme. The carefully designed optical setup, which comprises of three 4f optical architectures and a diffractive-imaging-based optical scheme, could encode the three plaintexts into a single noise-like intensity pattern. For the decryption, an iterative phase retrieval algorithm, together with a filter operation, is applied to extract the primary color images from the diffraction intensity map. Compared with previous methods, our proposal has successfully encrypted a color rather than grayscale image into a single intensity pattern, as a result of which the capacity and practicability have been remarkably enhanced. In addition, the performance and the security of it are also investigated. The validity as well as feasibility of the proposed method is supported by numerical simulations.
Optical stream-cipher-like system for image encryption based on Michelson interferometer.
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.
Quantum image encryption based on generalized affine transform and logistic map
Liang, Hao-Ran; Tao, Xiang-Yang; Zhou, Nan-Run
2016-07-01
Quantum circuits of the generalized affine transform are devised based on the novel enhanced quantum representation of digital images. A novel quantum image encryption algorithm combining the generalized affine transform with logistic map is suggested. The gray-level information of the quantum image is encrypted by the XOR operation with a key generator controlled by the logistic map, while the position information of the quantum image is encoded by the generalized affine transform. The encryption keys include the independent control parameters used in the generalized affine transform and the logistic map. Thus, the key space is large enough to frustrate the possible brute-force attack. Numerical simulations and analyses indicate that the proposed algorithm is realizable, robust and has a better performance than its classical counterpart in terms of computational complexity.
Adaptive Image Encryption Algorithm Based on Chaos Theory and Hash Function%基于混沌理论和Hash函数的自适应图像加密算法
赵希奇; 柏逢明; 吕贵花
2014-01-01
In this paper, a image encryption algorithm based on chaos theory and Hash functions are proposed for achive the digital image encryption. The scrambling transformation pixel matrix of image is got from extraction chaotic signal and Hash function by using the algorithm,then the adaptive diffusion for image gray scale is carried out by using piecewise Logistic mapping. This algorithm has large key space;the statistical attack capability is strong and effective against entropy attack;secret key sensitivity is strong,good performance;the corresponding security level can be met.%为了实现对数字图像的加密，提出了一种基于混沌理论和Hash函数的自适应图像加密算法。该算法用抽取的Lorenz混沌信号及Hash函数得到像素置乱矩阵，并对图像的像素进行置乱，利用分段Logistic映射对图像灰度进行自适应扩散。理论分析和仿真实验结果表明，该算法具有密钥空间大、抗统计攻击能力强、有效抵抗熵攻击、秘钥敏感性强等良好的性能，能够达到相应的安全水平。
Bi-serial DNA Encryption Algorithm(BDEA)
Prabhu, D
2011-01-01
The vast parallelism, exceptional energy efficiency and extraordinary information inherent in DNA molecules are being explored for computing, data storage and cryptography. DNA cryptography is a emerging field of cryptography. In this paper a novel encryption algorithm is devised based on number conversion, DNA digital coding, PCR amplification, which can effectively prevent attack. Data treatment is used to transform the plain text into cipher text which provides excellent security
A pipelined FPGA implementation of an encryption algorithm based on genetic algorithm
Thirer, Nonel
2013-05-01
With the evolution of digital data storage and exchange, it is essential to protect the confidential information from every unauthorized access. High performance encryption algorithms were developed and implemented by software and hardware. Also many methods to attack the cipher text were developed. In the last years, the genetic algorithm has gained much interest in cryptanalysis of cipher texts and also in encryption ciphers. This paper analyses the possibility to use the genetic algorithm as a multiple key sequence generator for an AES (Advanced Encryption Standard) cryptographic system, and also to use a three stages pipeline (with four main blocks: Input data, AES Core, Key generator, Output data) to provide a fast encryption and storage/transmission of a large amount of data.
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.
Yuan, Lin; Ran, Qiwen; Zhao, Tieyu
2017-02-01
In this paper an image authentication scheme is proposed based on double-image encryption and partial phase decryption in nonseparable Fractional Fourier transform domain. Two original images are combined and transformed into the nonseparable fractional Fourier domain. Only part of the phase information of the encrypted result is kept for decryption while the rest part of phase and all the amplitude information are discarded. The two recovered images are hardly recognized by visual inspection but can be authenticated by the nonlinear correlation algorithm. The numerical simulations demonstrate the viability and validity of the proposed image authentication scheme.
周业勤; 龙敏
2015-01-01
According to the properties of fractional Fourier transform, a kind of fractional Fourier transform image encryp-tion algorithm is analyzed. The key is not sensitive and the deciphering diagram is of great distortion, when with the naked eye on results chart to judge and extract the image data for comparison. Theoretical analysis and experimental results show that the algorithm is not sensitive to the key when the fractional Fourier transform is directly applied to image encryption. The introduction of RGB mapping to realize the cipher image display and transmission, result a great distortion in pixels.%从分数阶傅里叶变换的性质出发，对一类分数阶傅里叶变换图像加密算法进行分析。对原有算法结果图进行肉眼判断，提取图像中间结果数据进行对比分析，可知算法的密钥具有不敏感性，并且解密图具有很大失真。对分数傅里叶变换进行理论上的分析和讨论。分析及实验结果表明，直接使用分数阶傅里叶变换进行加密的算法对密钥并不敏感，存在安全隐患。为实现密文图像的显示和传输而引入的RGB映射将导致解密图像像素值失真。
王永皎; 王川
2013-01-01
In order to solve the security problem of digital images in communication channel transmission, we propose a new digital image encryption algorithm based on DWT-SVD. Singular value of the image has good irreversibility against the geometric attacks, and after mathematical transformation, the image centroid will not change. Based on the above analyses, in this paper we dwell on the designing idea of the DWT-SVD algorithm, and present the implementation steps of the algorithm. The DWT-SVD algorithm could be implemented on the constructed platform of image processing system based on DSP, and through the experimental test we can find that the DWT-SVD algorithm could well fight against geometric attack in communication channel, thereby ensure the security, invisibility and robustness of the images transmitted in the channel.%针对数字图像在信道传输中存在的安全性问题,提出DWT-SVD数字图像加密算法.在分析奇异值对几何攻击具有良好的不变性,以及图像质心在交换前后具有一一对应关系的基础上,详细阐述DWT-SVD算法的设计思想,同时给出算法的实现步骤.在构建的DSP图像处理系统平台上进行算法的实现,并通过实验测试得出,DWT-SVD算法可以很好地抗击信道中的几何攻击,从而保证了图像在信道中传输的安全性、隐蔽性和鲁棒性.
Adaptive Steganographic Algorithm using Cryptographic Encryption RSA Algorithms
Sharma, Manoj Kumar; Upadhyaya, Dr. Amit; Agarwal, Shalini
2013-01-01
Cryptography is the art of securing information by applying encryption and decryption on transmission data which ensure that the secret can be understood only by the right person.[1] Steganography is the process of sharing information in an undetectable way by making sure that nobody else can even detect the presence of a secret. If these two methods could be combined, it would provide a fool-proof security to information being communicated over a network. This paper propose two different ste...
Chaotic Image Encryption Based on Running-Key Related to Plaintext
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.
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.
邓晓衡; 廖春龙; 朱从旭; 陈志刚
2014-01-01
As the current popular chaos-based image encryption algorithms with the permutation-diffusion structure have security flaws of no immunity to attack. A new image encryption algorithm was proposed based on the analysis of current algorithms, which can well resist the chosen-plaintext and the chosen-ciphertext attacks. The algorithm uses Kent chaotic map to generate key streams, and produces the parameters of the chaotic system and the iteration times according to the characteristics of plaintext pixels and input key. Firstly, the positions of pixels were shuffled totally with the chaotic se-quence. Secondly, the 0 and 1 bit positions of image pixels were scrambled by using another chaotic sequence generated by the input key. The experimental results show that the algorithm cannot only resist the chosen plaintext attack and cho-sen ciphertext attack but also achieve better cryptographic properties,such as key space, statistical analysis.%针对当前流行的一类具有置乱-扩散结构的混沌图像加密算法存在的安全缺陷问题，提出了一种能抵抗选择明(密)文攻击的图像加密算法。算法采用Kent混沌映射生成密钥序列，并根据明文像素值的特征和输入的密钥，分别产生混沌系统的参数和预迭代次数。首先，利用混沌序列实现图像像素位置的全局置乱；其次，根据另一个新生成的混沌序列，实现对图像像素值中0 bit、1 bit的置乱。实现了混沌映射产生的序列与图像本身内容的关联，从而实现了中间密钥随明文自适应变化，能有效抵抗选择明(密)文攻击。实验结果表明，该算法克服了以往算法不能抵抗选择明(密)文攻击的缺陷，同时具有加密算法简单、密钥空间大等加密性能，并能较好地抵抗统计特性分析、差分分析攻击。
宋鑫超; 苏庆堂; 赵永升
2016-01-01
为解决当前图像加密算法采用独立的置乱与扩散操作，降低算法内联性，且忽略混沌序列生成存在的时延因素，使其难以抵御明文攻击等不足，提出一种内联时延混沌映射耦合 Lorenz系统的图像加密算法。将时间延迟引入 Logistic 映射中，生成 Arnold映射的初值；基于明文像素点，构造 Arnold映射迭代次数计算模型；根据 Arnold映射的迭代次数，建立其映射控制参数的计算函数，生成一组随机序列，利用位置集合，完成图像置乱；迭代超混沌 Lorenz 系统，生成4D序列组；引入密钥流，修正4D序列组；构造像素扩散机制，完成图像加密。实验结果表明，与当前加密结构相比，该算法拥有更高的保密性能与更强的密钥敏感性。%Using current image encryption algorithm is difficult to resist plaintext attacks induced by independently scrambling and diffusion operating resulting in reducing the algorithm’s inline,also the existing time delay factor of the chaos sequence is ig-nored,so the image encryption algorithm based on inline time delay chaotic map coupled with Lorenz system was proposed.The initial value of Arnold map was generated by introducing the time delay into the Logistic map.The iteration number model of Ar-nold map was constructed based on the pixels of plaintext.The initial value of Arnold map was generated by introducing the time delay into the Logistic map and basing on iteration number.The calculation function of the mapping control parameters was es-tablished based on the initial value for iterating to produce the random sequence and the image was permutated by position set. The 4D sequence group was generated by iterating the hyper-chaotic system.The pixel diffusion mechanism was constructed by the modified 4D sequence group with key stream to finish image encryption.Experimental results show that this algorithm has better security performance and stronger key
NEW SYMMETRIC ENCRYPTION SYSTEM BASED ON EVOLUTIONARY ALGORITHM
A. Mouloudi
2015-12-01
Full Text Available In this article, we present a new symmetric encryption system which is a combination of our ciphering evolutionary system SEC [1] and a new ciphering method called “fragmentation”. This latter allows the alteration of the appearance frequencies of characters from a given text. Our system has at its disposed two keys, the first one is generated by the evolutionary algorithm, the second one is generated after “fragmentation” part. Both of them are symmetric, session keys and strengthening the security of our system.
Somdip Dey
2012-06-01
Full Text Available Due to tremendous growth in communication technology, now it is a real problem / challenge to send some confidential data / information through communication network. For this reason, Nath et al. developed several information security systems, combining cryptography and steganography together, and the present method, ASA_QR, is also one of them. In the present paper, the authors present a new steganography algorithm to hide any small encrypted secret message inside QR CodeTM , which is then randomized and then, finally embed that randomized QR Code inside some common image. Quick Response Codes (or QR Codes are a type of two-dimensional matrix barcodes used for encoding information. It has become very popular recently for its high storage capacity. The present method is ASA_QR is a combination of strong encryption algorithm and data hiding in two stages to make the entire process extremely hard to break. Here, the secret message is encrypted first and hide it in a QR CodeTM and then again that QR CodeTM is embed in a cover file (picture file in random manner, using the standard method of steganography. In this way the data, which is secured, is almost impossible to be retrieved without knowing the cryptography key, steganography password and the exact unhide method. For encrypting data The authors used a method developed by Nath et al i.e. TTJSA, which is based on generalized modified Vernam Cipher, MSA and NJJSA method; and from the cryptanalysis it is seen that TTJSA is free from any standard cryptographic attacks, like differential attack, plain-text attack or any brute force attack. After encrypting the data using TTJSA,the authors have used standard steganographic method To hide data inside some host file. The present method may be used for sharing secret key, password, digital signature etc.
Cryptanalysis of a novel image encryption scheme based on improved hyperchaotic sequences
Özkaynak, Fatih; Özer, Ahmet Bedri; Yavuz, Sırma
2012-11-01
Chaotic cryptography is a new field that has seen a significant amount of research activity during the last 20 years. Despite the many proposals that use various methods in the design of encryption algorithms, there is a definite need for a mathematically rigorous cryptanalysis of these designs. In this study, we analyze the security weaknesses of the "C. Zhu, A novel image encryption scheme based on improved hyperchaotic sequences, Optics Communications 285 (2012) 29-37". By applying chosen plaintext attacks, we show that all the secret parameters can be revealed.
向涛; 余晨韵; 屈晋宇; 罗小松
2012-01-01
In this paper,a medical image encryption algorithm is proposed. The algorithm is based on the design principle of AES, and combined with Skew tent map. The standard procedure of AES is modified so that it can be suitable for the DICOM medical digital images. At first, the block size 4 * 4 in AddRoundKey is replaced by the size of an image.Then the basic information of patient is protected by our proposed algorithm. In addition,the AES's MixColumns and key schedule are improved.The theoretical analysis and numerical simulations show that the improved algorithm not only has better confusion diffusion effects with less computational overhead,but also can maintain the compatibility of DICOM file format.%本文基于AES算法的设计原理提出了一种改进的医学图像加密算法.针对AES算法结合斜帐篷映射对其进行改进,使其适合DICOM医学图像的数据特点.首先将AES中4*4的分块操作方式变成M*N的全图操作,其次增加了对病人基本信息的保护,最后改进了AES中列混合操作与密钥编排方式.通过理论分析与仿真实验证明改进算法具有较好的置乱效果、扩散性强,并且能够很好地保持DICOM文件格式的兼容性.
卢守东; 肖芳雄
2013-01-01
In order to protect digital image information effectively , a new universal encryption algorithm based on 3D chaotic system and its improved sequences is proposed .Firstly, according to the key and the digital image size m ×n , a 3D chaotic sequence with length of m ×n is generated .Then, the chaotic sequence is improved to possess the ideal pseudo-randomness property according to the sub-key and the type of image.Also according to the sub-key and the type of image , at the same time the chaotic sequence is converted to unsigned integer se-quence.Finally, the improved sequence is sorted for generating the corresponding subscript sequence , and pixel coordinates of the image will be scrambled based on it .Meanwhile , the pixel value permutation is realised by using the XOR operation between the unsigned integer se -quence and the corresponding pixel value in turn .In allusion to the malicious shearing or painting attacks ,a recovery algorithm based on neigh-bouring pixels characteristic is presented simultaneously .The effect of the encryption and security is also analysed by using the evaluation in-dex.Experimental results and theoretical analysis show that the algorithm has high running efficiency , large space of keys , good encryption effect, statistical characteristics and security , it also has strong ability in resisting the shearing or painting attacks and anti-noise as well.%为有效保护数字图像的信息，提出一种新的基于三维混沌系统及其改进序列的通用加密算法。首先，根据密钥及数字图像的大小m ×n，产生一个长度为m ×n的三维混沌序列。然后，根据子密钥及图像类型对混沌序列进行改进，使其具有理想的伪随机特性。同时，根据子密钥及图像类型将混沌序列转换为无符号整数序列。最后，对改进后的序列进行排序以生成相应的下标序列，并据此对图像进行像素坐标置乱，同时将无符号整数序列依次与对应的
Double-image encryption based on joint transform correlation and phase-shifting interferometry
Lina Shen; Jun Li; Hongsen Chang
2007-01-01
An image encryption method combining the joint transform correlator (JTC) architecture with phaseshifting interferometry to realize double random-phase encoding is proposed. The encrypted field and the decrypting key are registered as holograms by phase-shifting interferometry. This method can encrypt two images simultaneously to improve the encryption efficiency of the methods based on JTC architecture, and eliminate the system alignment constraint of the methods based on Mach-Zehnder interferometer (MZI)architecture. Its feasibility and validity are verified by computer simulations. Moreover, image encryption and decryption can be achieved at high speed optically or digitally. The encrypted data are suitable for Internet transmission.
Optical Image Encryption with Simplified Fractional Hartley Transform
LI Xin-Xin; ZHAO Dao-Mu
2008-01-01
We present a new method for image encryption on the basis of simplified fractional Hartley transform (SFRHT). SFRHT is a real transform as Hartley transform (HT) and furthermore, superior to HT in virtue of the advantage that it can also append fractional orders as additional keys for the purpose of improving the system security to some extent. With this method, one can encrypt an image with an intensity-only medium such as a photographic film or a CCD camera by spatially incoherent or coherent illumination. The optical realization is then proposed and computer simulations are also performed to verify the feasibility of this method.
Image encryption using random sequence generated from generalized information domain
Xia-Yan, Zhang; Guo-Ji, Zhang; Xuan, Li; Ya-Zhou, Ren; Jie-Hua, Wu
2016-05-01
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.
Color image encryption based on gyrator transform and Arnold transform
Sui, Liansheng; Gao, Bo
2013-06-01
A color image encryption scheme using gyrator transform and Arnold transform is proposed, which has two security levels. In the first level, the color image is separated into three components: red, green and blue, which are normalized and scrambled using the Arnold transform. The green component is combined with the first random phase mask and transformed to an interim using the gyrator transform. The first random phase mask is generated with the sum of the blue component and a logistic map. Similarly, the red component is combined with the second random phase mask and transformed to three-channel-related data. The second random phase mask is generated with the sum of the phase of the interim and an asymmetrical tent map. In the second level, the three-channel-related data are scrambled again and combined with the third random phase mask generated with the sum of the previous chaotic maps, and then encrypted into a gray scale ciphertext. The encryption result has stationary white noise distribution and camouflage property to some extent. In the process of encryption and decryption, the rotation angle of gyrator transform, the iterative numbers of Arnold transform, the parameters of the chaotic map and generated accompanied phase function serve as encryption keys, and hence enhance the security of the system. Simulation results and security analysis are presented to confirm the security, validity and feasibility of the proposed scheme.
Optical asymmetric image encryption using gyrator wavelet transform
Mehra, Isha; Nishchal, Naveen K.
2015-11-01
In this paper, we propose a new optical information processing tool termed as gyrator wavelet transform to secure a fully phase image, based on amplitude- and phase-truncation approach. The gyrator wavelet transform constitutes four basic parameters; gyrator transform order, type and level of mother wavelet, and position of different frequency bands. These parameters are used as encryption keys in addition to the random phase codes to the optical cryptosystem. This tool has also been applied for simultaneous compression and encryption of an image. The system's performance and its sensitivity to the encryption parameters, such as, gyrator transform order, and robustness has also been analyzed. It is expected that this tool will not only update current optical security systems, but may also shed some light on future developments. The computer simulation results demonstrate the abilities of the gyrator wavelet transform as an effective tool, which can be used in various optical information processing applications, including image encryption, and image compression. Also this tool can be applied for securing the color image, multispectral, and three-dimensional images.
Color image single-channel encryption based on tricolor grating theory
YUAN Qi-ping; YANG Xiao-ping; GAO Li-juan; ZHAI Hong-chen
2009-01-01
A method of color image single-channel encryption is proposed. The proposed method uses tricolor grating to encode a color image into a gray level image, then the gray level image is encrypted by double random phase encryption, so a color image is encrypted in a single-channel and its security is ensured. Computer simulations and the chromatic aberration analysis are given to prove the possibility of the proposed idea.The optical system is simpler and is easy to be applied into practice. The simulation results show that this method is efficiency to encrypt a color image, and it is robust.
A symmetrical image encryption scheme in wavelet and time domain
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.
DU Mao-Kang; HE Bo; WANG Yong
2011-01-01
Recently, the cryptosystem based on chaos has attracted much attention. Wang and Yu (Commun. Nonlin. Sci. Numer. Simulat. 14(2009)574) proposed a block encryption algorithm based on dynamic sequences of multiple chaotic systems. We analyze the potential Saws in the algorithm. Then, a chosen-plaintext attack is presented. Some remedial measures are suggested to avoid the flaws effectively. Furthermore, an improved encryption algorithm is proposed to resist the attacks and to keep all the merits of the original cryptosystem.
Chaos Encryption Algorithm to Deal with Security Threat to Internet of Things RFID
Tian Xiaoyong
2013-05-01
Full Text Available Internet of Things RFID system is mainly studied problem in current communication area, where the safety of code message become rather important. Chaos encryption algorithm can disperse not only the time area but the scale, which is suitable for computer to deal with and overcome the limitation of block encryption in DES and AES. Using Sequence of the digital to deal with initial value and combining the one dimensional Logistic chaos and three dimensional Lorenz algorithm realize common encryption algorithm of these two chaos methods to calculate the long-term random sequence under the limitation of precision and improve the security.
IMAGE ENCRYPTION TECHNIQUES USING CHAOTIC SCHEMES: A REVIEW
Monisha Sharma
2010-06-01
Full Text Available Cryptography is about communication in the presence of an adversary. It encompasses many problems like encryption, authentication, and key distribution to name a few. The field of modern cryptography providesa theoretical foundation based on which one can understand what exactly these problems are, how to evaluate protocols that purport to solve them and how to build protocols in whose security one can haveconfidence. Advanced digital technologies have made multimedia data widely available. Recently, multimedia applications become common in practice and thus security of multimedia data has become main concern.The basic issues pertaining to the problem of encryption has been discussed and also a survey on image encryption techniques based on chaotic schemes has been dealt in the present communication.The chaotic image encryption can be developed by using properties of chaos including deterministic dynamics, unpredictable behavior and non-linear transform. This concept leads to techniques that can simultaneously provide security functions and an overall visualcheck, which might be suitable in some applications. Digital images are widely used in various applications, that include military, legal and medical systems and these applications need to control access toimages and provide the means to verify integrity of images.
Image encryption using the two-dimensional logistic chaotic map
Wu, Yue; Yang, Gelan; Jin, Huixia; Noonan, Joseph P.
2012-01-01
Chaos maps and chaotic systems have been proved to be useful and effective for cryptography. In our study, the two-dimensional logistic map with complicated basin structures and attractors are first used for image encryption. The proposed method adopts the classic framework of the permutation-substitution network in cryptography and thus ensures both confusion and diffusion properties for a secure cipher. The proposed method is able to encrypt an intelligible image into a random-like one from the statistical point of view and the human visual system point of view. Extensive simulation results using test images from the USC-SIPI image database demonstrate the effectiveness and robustness of the proposed method. Security analysis results of using both the conventional and the most recent tests show that the encryption quality of the proposed method reaches or excels the current state-of-the-art methods. Similar encryption ideas can be applied to digital data in other formats (e.g., digital audio and video). We also publish the cipher MATLAB open-source-code under the web page https://sites.google.com/site/tuftsyuewu/source-code.
DATA SECURITY IN LOCAL AREA NETWORK BASED ON FAST ENCRYPTION ALGORITHM
G. Ramesh
2010-06-01
Full Text Available Hacking is one of the greatest problems in the wireless local area networks. Many algorithms have been used to prevent the outside attacks to eavesdrop or prevent the data to be transferred to the end-user safely and correctly. In this paper, a new symmetrical encryption algorithm is proposed that prevents the outside attacks. The new algorithm avoids key exchange between users and reduces the time taken for the encryption and decryption. It operates at high data rate in comparison with The Data Encryption Standard (DES, Triple DES (TDES, Advanced Encryption Standard (AES-256, and RC6 algorithms. The new algorithm is applied successfully on both text file and voice message.
基于混沌系统和极化恒等式的数字图像加密算法%An Image Encryption Algorithm Based on Chaotic System and Polarized Identity
周文杰; 冯嘉礼
2009-01-01
混沌系统具有初值敏感性,参数敏感性和类随机性等特性将图像分成大小为8 8的图像子块,利用经典的Logistic方程产生的混沌序列并对其排序生成匹配模板来改变图像子块的位置,然后利用极化恒等式内积分解加密算法改变图像像素的值因此,基于混沌系统和极化恒等式的数字图像加密算法使图像的像素的位置和值都发生了变化,实现了图像的混淆和扩散仿真实验表明该方法进行图像加密具有可行性和安全性.%Chaotic system has such attributes as initial value sensitivity ,sensitivity of the parameters and random - like.. On the one hand ,dignital image is divided into 8 8 sub_block image . The sub_block images scrambled by the template matching that can be gotten by the typical Logistic equation . On the other hand encryption algorithm based on inner product polarized identity and vector inner product decomposition of a constant change each pixel value in an image. So the method can attain the purpose of image confusion and diffusion.Through theoretical analysis and simulation , the method was proved to work well.
Design of an image encryption scheme based on a multiple chaotic map
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.
2013-01-01
Disclosed is a method of transmitting a data set using encryption, wherein the method comprises the steps of: selecting a first encryption technique, wherein said first encryption technique comprises a first encryption algorithm for encrypting plain data into cipher data, and a first decryption...... 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...
Gauss-Markov encryption matrix construct and image encryption application%Gauss-Markov加密矩阵构造及图像加密应用
邹阿金; 刘勇华; 罗移祥
2012-01-01
To solve the problem of encryption matrix is difficult to construct, a novel algorithm is proposed to get the encryption matrix. First, a stochastic sequence is generated by Gauss-Markov process. Then, it is converted into a series of low-order integer matrixes and multiple the selected matrices with determinant equal to 1 each other by using tensor production method. Thus, we can construct some high order encryption matrices and use it in digital image encryption. The encryption instance and theoretical analysis show that the proposed algorithm can produce encryption matrices with high security, and have good random characteristics and autocorrelation to meet the requirement of cryptography.%为了解决加密矩阵难以构造的问题,提出一种获得整数矩阵的新算法,利用Gauss-Markov过程生成一个随机序列,将该序列转换为一系列的低阶整数矩阵,从中寻找行列式等于l的整数矩阵,并对这些矩阵进行张量积运算得到高阶加密矩阵,应用于数字图像加密.加密实例和理论分析及对比表明,该算法可自动生成安全性很高的加密矩阵,且加密结果具有良好的随机特性和自相关性,能满足密码学的要求.
A New Image Encryption Algorithm Based on Quantum Key and Chaotic Mapping%一种基于量子密钥与混沌映射的图像加密新方法
张克; 高会新
2016-01-01
According to the certifiable security of quantum key distribution protocol and pseudo random characteristics of the chaotic sequence, a new image encryption method that combined quantum key and chaotic mapping was proposed. Firstly, initial quantum key was obtained with BB84 protocol, then quantum key was formed after error checking for the initial key with data consulting approach, and the last key stream was achieved by combining the quantum key and chaotic sequence from Logistic mapping. Lastly, pixel values were replaced with XOR operation of pixel values and the last key stream, and image was encrypted. Simulation results and analysis show that, the new cryptographic algorithm can more effectively resist statistics-based and plain text attack, while ensuring the security of key transformation; the key stream results from the new method is highly sensitive to initial parameters.%依据量子密钥分配协议具有可证明的安全性及混沌序列的伪随机性，提出一种基于量子密钥与混沌映射相结合的图像加密新方法。根据BB84协议获得初始量子密钥，采用数据协商方式对初始密钥进行纠错，再将所得量子密钥与Logistic混沌序列相融合，生成最终的密钥流，以此对图像像素值通过异或运算进行置换实现图像加密。仿真结果与分析表明：本文方法在保证密钥传输安全性的同时，可以更为有效地掩盖图像的统计信息、抵御明文攻击；密钥流对于初始参数具有高敏感性。
Image encryption using a synchronous permutation-diffusion technique
Enayatifar, Rasul; Abdullah, Abdul Hanan; Isnin, Ismail Fauzi; Altameem, Ayman; Lee, Malrey
2017-03-01
In the past decade, the interest on digital images security has been increased among scientists. A synchronous permutation and diffusion technique is designed in order to protect gray-level image content while sending it through internet. To implement the proposed method, two-dimensional plain-image is converted to one dimension. Afterward, in order to reduce the sending process time, permutation and diffusion steps for any pixel are performed in the same time. The permutation step uses chaotic map and deoxyribonucleic acid (DNA) to permute a pixel, while diffusion employs DNA sequence and DNA operator to encrypt the pixel. Experimental results and extensive security analyses have been conducted to demonstrate the feasibility and validity of this proposed image encryption method.
Wang, Zhi-peng; Zhang, Shuai; Liu, Hong-zhao; Qin, Yi
2014-12-01
Based on phase retrieval algorithm and QR code, a new optical encryption technology that only needs to record one intensity distribution is proposed. In this encryption process, firstly, the QR code is generated from the information to be encrypted; and then the generated QR code is placed in the input plane of 4-f system to have a double random phase encryption. For only one intensity distribution in the output plane is recorded as the ciphertext, the encryption process is greatly simplified. In the decryption process, the corresponding QR code is retrieved using phase retrieval algorithm. A priori information about QR code is used as support constraint in the input plane, which helps solve the stagnation problem. The original information can be recovered without distortion by scanning the QR code. The encryption process can be implemented either optically or digitally, and the decryption process uses digital method. In addition, the security of the proposed optical encryption technology is analyzed. Theoretical analysis and computer simulations show that this optical encryption system is invulnerable to various attacks, and suitable for harsh transmission conditions.
Efficient Hardware Implementation of the Lightweight Block Encryption Algorithm LEA
Donggeon Lee
2014-01-01
Full Text Available Recently, due to the advent of resource-constrained trends, such as smartphones and smart devices, the computing environment is changing. Because our daily life is deeply intertwined with ubiquitous networks, the importance of security is growing. A lightweight encryption algorithm is essential for secure communication between these kinds of resource-constrained devices, and many researchers have been investigating this field. Recently, a lightweight block cipher called LEA was proposed. LEA was originally targeted for efficient implementation on microprocessors, as it is fast when implemented in software and furthermore, it has a small memory footprint. To reflect on recent technology, all required calculations utilize 32-bit wide operations. In addition, the algorithm is comprised of not complex S-Box-like structures but simple Addition, Rotation, and XOR operations. To the best of our knowledge, this paper is the first report on a comprehensive hardware implementation of LEA. We present various hardware structures and their implementation results according to key sizes. Even though LEA was originally targeted at software efficiency, it also shows high efficiency when implemented as hardware.
Satellite Image Security Improvement by Combining DWT-DCT Watermarking and AES Encryption
Naida.H.Nazmudeen
2014-06-01
Full Text Available With the large-scale research in space sciences and technologies, there is a great demand of satellite image security system for providing secure storage and transmission of satellite images. As the demand to protect the sensitive and valuable data from satellites has increased and hence proposed a new method for satellite image security by combining DWT-DCT watermarking and AES encryption. Watermarking techniques developed for multimedia data cannot be directly applied to the satellite images because here the analytic integrity of the data, rather than perceptual quality, is of primary importance. To improve performance, combine discrete wavelet transform (DWT with another equally powerful transform; the discrete cosine transform (DCT. The combined DWT-DCT watermarking algorithm’s imperceptibility was better than the performance of the DWT approach. Modified decision based unsymmetrical trimmed median filter (MDBUTMF algorithm is proposed for the restoration of satellite images that are highly corrupted by salt and pepper noise. Satellite images desire not only the watermarking for copyright protection but also encryption during storage and transmission for preventing information leakage. Hence this paper investigates the security and performance level of joint DWT-DCT watermarking and Advanced Encryption Standard (AES for satellite imagery. Theoretical analysis can be done by calculating PSNR and MSE. The experimental results demonstrate the efficiency of the proposed scheme, which fulfils the strict requirements concerning alterations of satellite images.
Vector Quantization Techniques For Partial Encryption of Wavelet-based Compressed Digital Images
H. A. Younis
2009-01-01
Full Text Available The use of image communication has increased in recent years. In this paper, newpartial encryption schemes are used to encrypt only part of the compressed data. Only6.25-25% of the original data is encrypted for four different images, resulting in asignificant reduction in encryption and decryption time. In the compression step, anadvanced clustering analysis technique (Fuzzy C-means (FCM is used. In the encryptionstep, the permutation cipher is used. The effect of number of different clusters is studied.The proposed partial encryption schemes are fast and secure, and do not reduce thecompression performance of the underlying selected compression methods as shown inexperimental results and conclusion.
An image encryption scheme based on quantum logistic map
Akhshani, A.; Akhavan, A.; Lim, S.-C.; Hassan, Z.
2012-12-01
The topic of quantum chaos has begun to draw increasing attention in recent years. While a satisfactory definition for it is not settled yet in order to differentiate between its classical counterparts. Dissipative quantum maps can be characterized by sensitive dependence on initial conditions, like classical maps. Considering this property, an implementation of image encryption scheme based on the quantum logistic map is proposed. The security and performance analysis of the proposed image encryption is performed using well-known methods. The results of the reliability analysis are encouraging and it can be concluded that, the proposed scheme is efficient and secure. The results of this study also suggest application of other quantum maps such as quantum standard map and quantum baker map in cryptography and other aspects of security and privacy.
Hardware realization of chaos based block cipher for image encryption
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.
彭川
2012-01-01
为了有效改进细胞自动机加密系统的实现复杂度和加解密效率,提出了一种二阶可逆耦合触发细胞自动机的图像加密方法.通过对简单的可逆细胞自动机进行扩展,构造二阶可逆细胞自动机,并以耦合触发规则对明文图像实行分块加密.二阶可逆细胞自动机的转移状态由其当前状态以及前一状态决定,有效增大了邻域范围,并且因为采用耦合触发规则,因此能明显增大加密系统的密钥空间,保证了系统的计算安全性.与一般触发自动机反向迭代的串行加密方式相比,该方法对于每个细胞的加密具有本质并行性,因此具有极高的加解密效率.通过实验验证其性能,结果表明与其它算法相比,该算法具有较大的密钥空间,能够有效抵抗蛮力攻击和差分分析攻击,且较小的邻域半径即可得到良好的加密效果,因此非常便于硬件实现.%To effectively improve the implement complexity and execution efficiency, an algorithm for image encryption is proposed which is based on two-order reversible couple toggle cellular automata (CA). By ways that extending the structure of simple reversible CA (RCA) and adopting couple toggle rules, the algorithm ciphers image which is divided into blocks previously. The CA's state is determined by previous state and next state, so it has larger key space and this can make system safe enough. Compared with general toggle CA (TCA) methods, the algorithm has much better efficiency because each cell is updated parallel Experiments and analysis indicate that this method has an enough large key space, high cipher and decipher speed and good scrambling effect. And the cryptosystem can resist brute attack and differential attack effectively.
A Light-weight Symmetric Encryption Algorithm Based on Feistel Cryptosystem Structure
Jingli Zheng
2014-12-01
Full Text Available WSNs is usually deployed in opening wireless environment, its data is easy to be intercepted by attackers. It is necessary to adopt some encryption measurements to protect data of WSNs. But the battery capacity, CPU performance and RAM capacity of WSNs sensors are all limited, the complex encryption algorithm is not fitted for them. The paper proposed a light-level symmetrical encryption algorithm: LWSEA, which adopt minor encryption rounds, shorter data packet and simplified scrambling function. So the calculation cost of LWSEA is very low. We also adopt longer-bit Key and circular interpolation method to produce Child-Key, which raised the security of LWSEA. The experiments demonstrate that the LWSEA possess better "avalanche effect" and data confusion degree, furthermore, its calculation speed is far faster than DES, but its resource cost is very low. Those excellent performances make LWSEA is much suited for resource-restrained WSNs.
Composite encryption algorithm based on combing chaos control with choosing rule%基于混沌控制的选择复合加密算法
王阳; 吴成茂; 梁睿
2012-01-01
为了提高图像信息的安全性,提出一种混沌技术和像素扩散加密相结合的图像加密新算法。利用Runge-Kutta方法求解四维混沌系统并经非线性处理产生混沌序列,用以控制图像扩散加密方式并获得多种扩散加密方法相融合的复合加密算法。对图像加密结果的相邻像素相关性、密钥敏感性、抗差分攻击等性能所进行的分析研究以及相关实验结果均表明,所提新算法具有可行性,且安全性能较高。%In order to enhance the security of image information, a New Image Encryption Algorithm based on combination of chaos control with pixel diffusion encryption is proposed. Firstly, Runge-Kutta method is used to solve fourth-dimension chaotic systems, and obtains a chaotic integer sequence by means of non-linear processing. Secondly, image diffusion encryption is controlled by combining the chaotic integer sequence with choosing rule, and obtained the composite encryption algorithm which includes a variety of diffusion encryption methods. In the end, anayze the correlations between pixels, the sensitivity of keys, against differential cryptanalysis of the image encryption results. Experimental results show that, the image encryption algorithm proposed in the paper is feasible and has high safety performance.
Improving Image Encryption Using 3D Cat Map and Turing Machine
Nehal A. Mohamed
2016-01-01
Full Text Available Security of data is of prime importance. Security is a very complex and vast topic. One of the common ways to protect this digital data from unauthorized eavesdropping is encryption. This paper introduces an improved image encryption technique based on a chaotic 3D cat map and Turing machine in the form of dynamic random growth technique. The algorithm consists of two main sections: The first does a preprocessing operation to shuffle the image using 3D chaotic map in the form of dynamic random growth technique. The second uses Turing machine simultaneous with shuffling pixels’ locations to diffuse pixels’ values using a random key that is generated by chaotic 3D cat map. The hybrid compound of a 3D chaotic system and Turing machine strengthen the encryption performance and enlarge the key space required to resist the brute force attacks. The main advantages of such a secure technique are the simplicity and efficiency. These good cryptographic properties prove that it is secure enough to use in image transmission systems.
CRYPTANALYSIS OF AN IMAGE ENCRYPTION SCHEME WITH A PSEUDORANDOM PERMUTATION AND ITS IMPROVED VERSION
Wang Jing; Jiang Guoping; Lin Bing
2012-01-01
Under Kerckhoff principle,this paper discusses the security property of an image encryption scheme with a pseudorandom permutation.Some findings on the security problems of the algorithm are reported in the following:(1) If each row or column of the plain-image matrix is the same,the receiver cannot decrypt correctly.(2) Each plain-text word is correlated with single cipher-text word,but independent of other cipher-text word,which cannot meet the principles of algorithm designdiffusion and confusion.(3) If the cycle numbers β are relatively small,statistics attack can be used to reveal some visual information of any other plain-images encrypted with the same secret key.Considering the above problems,we propose an improved algorithm and then analyze its performance.Theoretical analysis and simulation results show that the improved algorithm can obtain better cryptographic properties,such as statistical characteristics,difference characteristics,and so on.
Chaos-based encryption for fractal image coding
Yuen Ching-Hung; Wong Kwok-Wo
2012-01-01
A chaos-based cryptosystem for fractal image coding is proposed.The Rényi chaotic map is employed to determine the order of processing the range blocks and to generate the keystream for masking the encoded sequence.Compared with the standard approach of fractal image coding followed by the Advanced Encryption Standard,our scheme offers a higher sensitivity to both plaintext and ciphertext at a comparable operating efficiency.The keystream generated by the Rényi chaotic map passes the randomness tests set by the United States National Institute of Standards and Technology,and so the proposed scheme is sensitive to the key.
Full Restoration of Visual Encrypted Color Images
Persson, Simeon
2011-01-01
While strictly black and white images have been the basis for visual cryptography, there has been a lack of an easily implemented format for colour images. This paper establishes a simple, yet secure way of implementing visual cryptography with colour, assuming a binary data representation.
Optical encryption for large-sized images using random phase-free method
Shimobaba, Tomoyoshi; Endo, Yutaka; Hirayama, Ryuji; Hiyama, Daisuke; Hasegawa, Satoki; Nagahama, Yuki; Sano, Marie; Sugie, Takashige; Ito, Tomoyoshi
2015-01-01
We propose an optical encryption framework that can encrypt and decrypt large-sized images beyond the size of the encrypted image using our two methods: random phase-free method and scaled diffraction. In order to record the entire image information on the encrypted image, the large-sized images require the random phase to widely diffuse the object light over the encrypted image; however, the random phase gives rise to the speckle noise on the decrypted images, and it may be difficult to recognize the decrypted images. In order to reduce the speckle noise, we apply our random phase-free method to the framework. In addition, we employ scaled diffraction that calculates light propagation between planes with different sizes by changing the sampling rates.
QR code based noise-free optical encryption and decryption of a gray scale image
Jiao, Shuming; Zou, Wenbin; Li, Xia
2017-03-01
In optical encryption systems, speckle noise is one major challenge in obtaining high quality decrypted images. This problem can be addressed by employing a QR code based noise-free scheme. Previous works have been conducted for optically encrypting a few characters or a short expression employing QR codes. This paper proposes a practical scheme for optically encrypting and decrypting a gray-scale image based on QR codes for the first time. The proposed scheme is compatible with common QR code generators and readers. Numerical simulation results reveal the proposed method can encrypt and decrypt an input image correctly.
Encryption On Grayscale Image For Digital Image Confidentiality Using Shamir Secret Sharing Scheme
Rodiah; Anggraini, Dyah; Fitrianingsih; Kazhimi, Farizan
2016-04-01
The use of high-frequency internet in the process of exchanging information and digital transaction is often accompanied by transmitting digital image in the form of raster images. Secret sharing schemes are multiparty protocols that related to the key establishment which provides protection against any threats of losing cryptography key. The greater the key duplication, the higher the risk of losing the key and vice versa. In this study, Secret Sharing Method was used by employing Shamir Threshold Scheme Algorithm on grayscale digital image with the size of 256×256 pixel obtaining 128×128 pixels of shared image with threshold values (4, 8). The result number of shared images were 8 parts and the recovery process can be carried out by at least using 4 shares of the 8 parts. The result of encryption on grayscale image is capable of producing vague shared image (i.e., no perceptible information), therefore a message in the form of digital image can be kept confidential and secure.
Performance Analysis of Most Common Encryption Algorithms on Different Web Browsers
R. Umarani
2012-11-01
Full Text Available The hacking is the greatest problem in the wireless local area network (WLAN. Many algorithms like DES, 3DES, AES,UMARAM, RC6 and UR5 have been used to prevent the outside attacks to eavesdrop or prevent the data to be transferred to the end-user correctly. We have proposed a Web programming language to be analyzed with five Web browsers in term of their performances to process the encryption of the programming language’s script with the Web browsers. This is followed by conducting tests simulation in order to obtain the best encryption algorithm versus Web browser. The results of the experimental analysis are presented in the form of graphs. We finally conclude on the findings that different algorithms perform differently to different Web browsers like Internet Explorer, Mozilla Firefox, Opera and Netscape Navigator. Hence, we now determine which algorithm works best and most compatible with which Web browser.A comparison has been conducted for those encryption algorithms at different settings for each algorithm such as encryption/decryption speed in the different web Browsers. Experimental results are given to demonstrate the effectiveness of each algorithm.
Multifractional Fourier Transform Method and Its Applications to Image Encryption
RANQiwen; WANGQi; MAJing; TANLiying
2003-01-01
The multiplicity of the fractional Fourier transform(FRFT),which is intrinsic in any fractional operator,has been claimed by several authors,but never across-the-board developed.Particularly,the weight-type FRFT(WFRFT) has not been investigated.Starting with defining the multifractional Fourier transform (MFRFT),we gained the generalization permutation matrix group (GPMG)representation and multiplicity of the MFRFT,and the relationships among the MFRFT the standard WFRFT and the standard CFRFT.Finally,as a application,a novel image encryption method hased on the MFRFT is propounded.Similation results show that this method is safe,practicable and impactful.
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.
Yau, Her-Terng; Hung, Tzu-Hsiang; Hsieh, Chia-Chun
2012-01-01
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.
An Investigation into Encrypted Message Hiding Through Images Using LSB
FAHIM IRFAN ALAM
2011-02-01
Full Text Available Data security has become a cause of concern because of the electronic spying especially in the military, government and many sectors of communication fields. This paper investigates a representation forembedding secure data within an image based on substitution method which gives the scope of large amount of secret message hiding within digital images. Specifically we used least significant bit (LSBsubstitution method to encrypt the message in image file. For improving the performance of LSB which is very simple by nature, we performed noise filtering at the beginning of the process to ensure noise-free data to be transmitted through the image. Also, after the extraction of the secure message at the receiver portion of the network, we used Automatic Repeat reQuest (ARQ method as the error detection and correction process to ensure that the correct data has been transmitted and no information is lost. The improved framework resulted in satisfactory outcomes.
Farouk, Hala A
2011-01-01
The hybrid hiding encryption algorithm, as its name implies, embraces concepts from both steganography and cryptography. In this exertion, an improved micro-architecture Field Programmable Gate Array (FPGA) implementation of this algorithm is presented. This design overcomes the observed limitations of a previously-designed micro-architecture. These observed limitations are: no exploitation of the possibility of parallel bit replacement, and the fact that the input plaintext was encrypted serially, which caused a dependency between the throughput and the nature of the used secret key. This dependency can be viewed by some as vulnerability in the security of the implemented micro-architecture. The proposed modified micro-architecture is constructed using five basic modules. These modules are; the message cache, the message alignment module, the key cache, the comparator, and at last the encryption module. In this work, we provide comprehensive simulation and implementation results. These are: the timing diagra...
Stego Optical Encryption Based on Chaotic Baker's Map Transformation
Hussain, Iqtadar; Gondal, Muhammad Asif
2014-06-01
In this article, an optical image encryption algorithm based on chaotic baker's map is presented. The stego-image is encrypted with the help of double random phase encoding algorithm and then produced disorder with the help of chaotic transformation. Security test shows that the reading of proposed algorithm is very close to the optimal values.
Lang, Jun
2015-03-01
In this paper, we propose a novel color image encryption method by using Color Blend (CB) and Chaos Permutation (CP) operations in the reality-preserving multiple-parameter fractional Fourier transform (RPMPFRFT) domain. The original color image is first exchanged and mixed randomly from the standard red-green-blue (RGB) color space to R‧G‧B‧ color space by rotating the color cube with a random angle matrix. Then RPMPFRFT is employed for changing the pixel values of color image, three components of the scrambled RGB color space are converted by RPMPFRFT with three different transform pairs, respectively. Comparing to the complex output transform, the RPMPFRFT transform ensures that the output is real which can save storage space of image and convenient for transmission in practical applications. To further enhance the security of the encryption system, the output of the former steps is scrambled by juxtaposition of sections of the image in the reality-preserving multiple-parameter fractional Fourier domains and the alignment of sections is determined by two coupled chaotic logistic maps. The parameters in the Color Blend, Chaos Permutation and the RPMPFRFT transform are regarded as the key in the encryption algorithm. The proposed color image encryption can also be applied to encrypt three gray images by transforming the gray images into three RGB color components of a specially constructed color image. Numerical simulations are performed to demonstrate that the proposed algorithm is feasible, secure, sensitive to keys and robust to noise attack and data loss.
Adelaïde Nicole Kengnou Telem
2014-01-01
Full Text Available A robust gray image encryption scheme using chaotic logistic map and artificial neural network (ANN is introduced. In the proposed method, an external secret key is used to derive the initial conditions for the logistic chaotic maps which are employed to generate weights and biases matrices of the multilayer perceptron (MLP. During the learning process with the backpropagation algorithm, ANN determines the weight matrix of the connections. The plain image is divided into four subimages which are used for the first diffusion stage. The subimages obtained previously are divided into the square subimage blocks. In the next stage, different initial conditions are employed to generate a key stream which will be used for permutation and diffusion of the subimage blocks. Some security analyses such as entropy analysis, statistical analysis, and key sensitivity analysis are given to demonstrate the key space of the proposed algorithm which is large enough to make brute force attacks infeasible. Computing validation using experimental data with several gray images has been carried out with detailed numerical analysis, in order to validate the high security of the proposed encryption scheme.
Opto-digital image encryption by using Baker mapping and 1-D fractional Fourier transform
Liu, Zhengjun; Li, She; Liu, Wei; Liu, Shutian
2013-03-01
We present an optical encryption method based on the Baker mapping in one-dimensional fractional Fourier transform (1D FrFT) domains. A thin cylinder lens is controlled by computer for implementing 1D FrFT at horizontal direction or vertical direction. The Baker mapping is introduced to scramble the amplitude distribution of complex function. The amplitude and phase of the output of encryption system are regarded as encrypted image and key. Numerical simulation has been performed for testing the validity of this encryption scheme.
Ruisong Ye
2014-03-01
Full Text Available A secure image encryption scheme based on 2D skew tent map is proposed for the encryption of color images. The proposed encryption scheme is composed of one permutation process and one substitution process. The 3D color plain-image matrix is converted to 2D image matrix first, then 2D skew tent map is utilized to generate chaotic sequences, which are used for both permutation process and substitution process. The chaotic sequence for permutation process is dependent on plain-image and cipher keys, resulting in good key sensitivity and plaintext sensitivity. The substitution process is first initiated with the initial vectors generated by the cipher keys and 2D skew tent map, then the gray values of row and column pixels of 2D image matrix are mixed with the pseudorandom number sequences via bitxoring operation. Both permutation process and substitution process are executed row-by-row and column-by-column instead of pixel-by-pixel to improve the speed of encryption. The security and performance of the proposed image encryption have been analyzed, including histograms, correlation coefficients, information entropy, key sensitivity analysis, key space analysis, differential analysis, encryption/decryption rate analysis etc. All the experimental results suggest that the proposed image encryption scheme is robust and secure and can be used for secure image and video communication applications.
Cheremkhin, Pavel A.; Evtikhiev, Nikolay N.; Krasnov, Vitaly V.; Rodin, Vladislav G.; Starikov, Sergey N.
2014-05-01
At present time methods of optical encryption are actively developed. The majority of existing methods of optical encryption use not only light intensity distribution, easily registered with photosensors, but also its phase distribution which require application of complex holographic schemes in conjunction with spatially coherent light. This leads to complex optical schemes and low decryption quality. To eliminate these disadvantages it is possible to implement optical encryption using spatially incoherent illumination which requires registration of light intensity distribution only. However this applies new restrictions on encryption keys: Fourier spectrum amplitude distribution of encryption key should overlap Fourier spectrum amplitude distribution of image to be encrypted otherwise loss of information is unavoidable. Therefore it seems that best key should have white spectrum. On the other hand due to fact that only light intensity distribution is registered, spectra of image to be encrypted and encryption key always have peaks at zero frequency and their heights depend on corresponding total energy. Since encrypted image contains noise, ratio of its average spectrum energy to noise average energy determines signal to noise ratio of decrypted image. Therefore ratio of amplitude at zero frequency to average spectrum amplitude (RZA) of encryption key defines decrypted images quality. For generation of encryption keys with low RZA method of direct search with random trajectory (DSRT) was used. To estimate impact of key RZA on decrypted images error numerical experiments were conducted. For experiments keys with different RZA values but with same energy value were generated and used. Numerically simulated optical encryption and decryption of set of test images was conducted. Results of experiment demonstrate that application of keys with low RZA generated by DSRT method leads to up to 20% lower error in comparison to keys generated by means of uniform random
Image encryption based on the reality-preserving multiple-parameter fractional Fourier transform
Lang, Jun
2012-05-01
In recent years, a number of methods have been proposed in the literature for the encryption of two-dimensional information by using the fractional Fourier transform, but most of their encryptions are complex values and need digital hologram technique to record information, which is inconvenient for digital transmission. In this paper, we propose a new approach for image encryption based on the real-valuedness and decorrelation property of the reality-preserving multiple-parameter fractional Fourier transform in order to meet the requirements of the secure image transmission. In the proposed scheme, the original and encrypted images are respectively in the spatial domain and the reality-preserving multiple-parameter fractional Fourier transformed domain determined by the encryption keys. Numerical simulations are performed to demonstrate that the proposed method is reliable and more robust to blind decryption than several existing methods.
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.
Applying Encryption Algorithm for Data Security and Privacy in Cloud Computing
Mohit Marwaha
2013-01-01
Full Text Available Cloud computing is the next big thing after internet in the field of information technology; some say its a metaphor for internet. It is an Internet-based computing technology, in which software, shared recourses and information, are provided to consumers and devices on-demand, and as per users requirement on a pay per use model. Even though the cloud continues to grow in popularity, Usability and respectability, Problems with data protection and data privacy and other Security issues play a major setback in the field of Cloud Computing. Privacy and security are the key issue for cloud storage. Encryption is a well known technology for protecting sensitive data. Use of the combination of Public and Private key encryption to hide the sensitive data of users, and cipher text retrieval. The paper analyzes the feasibility of the applying encryption algorithm for data security and privacy in cloud Storage.
Composite Chaotic Pseudo-Random Sequence Encryption Algorithm for Compressed Video
袁春; 钟玉琢; 杨士强
2004-01-01
Stream cryptosystems, which implement encryption by selecting parts of the block data and header information of the compressed video stream, achieve good real-time encryption with high flexibility. Chaotic random number generator-based approaches, for example, logistics maps, are comparatively promising approachs, but are vulnerable to attacks by nonlinear dynamic forecasting. A composite chaotic cryptography scheme was developed to encrypt the compressed video with the logistics map with a Z(231?1) field linear congruential algorithm to strengthen the security of the mono-chaotic cryptography. The scheme maintained real-time performance and flexibility of the chaotic sequence cryptography. The scheme also integrated asymmetrical public-key cryptography and encryption and identity authentification of control parameters at the initialization phase. Encryption is performed in a layered scheme based on the importance of the data in a compressed video stream. The composite chaotic cryptography scheme has the advantage that the value and updating frequency of the control parameters can be changed online to satisfy the network requirements and the processor capability, as well as the security requirements. Cryptanalysis shows that the scheme guarantees robust security,provides good real-time performance,and has flexible implementation. Statistical evaluations and tests verify that the scheme is effective.
Ji, Shiyu; Tong, Xiaojun; Zhang, Miao
2013-01-01
We propose several methods to transplant the compound chaotic image encryption scheme with permutation based on three-dimensional (3-D) baker onto image formats such as the joint photographic experts group (JPEG) and graphics interchange format (GIF). The new methods avert the discrete cosine transform and quantization, which result in floating point precision loss, and succeed to encrypt and decrypt JPEG images lossless. The ciphered JPEG images generated by our solution own much better randomness than most other existing schemes. Our proposed method for GIF keeps the property of animation successfully. The security test results indicate the proposed methods have high security, and the speed of our algorithm is faster than classical solutions. Since JPEG and GIF image formats are popular contemporarily, we show that the prospect of chaotic image encryption is promising.
Separable and Error-Free Reversible Data Hiding in Encrypted Image with High Payload
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.
An Image Encryption Scheme Based on Bit Circular Shift and Bi-directional Diffusion
Ruisong Ye
2013-12-01
Full Text Available A novel image encryption scheme based on chaotic system is proposed. The proposed encryption scheme utilizes one tent map to generate a pseudo-random sequence and then shift the bits of the expanding 0-1 image circularly so as to shuffle the image gray values. To make the encryption scheme resist differential attack efficiently, generalized Arnold maps and Bernoulli shift maps are applied to produce two pseudo-random gray value sequences and then diffuse the gray values bi-directionally. The bit circular shift process and diffusion processes greatly confuse the statistical nature between plain-images and cipher-images. Security analyses including key sensitivity analysis, key space analysis, statistical analysis, differential attack analysis and information entropy analysis are performed. All the experimental results demonstrate that the proposed image encryption scheme possesses large key space to frustrate brute-force attack efficiently and can resist statistical attack, differential attack, etc.
潘强; 印鉴
2015-01-01
针对当前的彩色图像加密方案都是将 R、G、B 三基色的像素分离来单独进行加密，且生成的混沌序列不依赖于明文信息，导致密文随机性和抗攻击性较差等不足，提出了提取明文信息耦合多混沌像素混乱的彩图RGB 同步加密算法。首先，将图像 RGB 三基色的像素进行分离、二值化与矢量化处理，得到 RGB 三个矢量；重组这些矢量，得到 R、G、B 各像素均彼此依赖的置乱矩阵；然后，通过提取明文图像信息来控制四个超混沌系统的迭代，得到与明文相关的随机序列，对置乱矩阵完成列、行扩散。仿真结果表明，与其他彩图加密机制相比，加密系统的安全性更高，且密钥空间更大，密钥敏感性强。%In order to solve these defects such as poor performance of cipher random as well as anti-attack induced by the ob-tained sequence aren't dependent on the plaintext and separately encrypting RGB pixel in current color image encryption sys-tems, this paper proposed the lossless synchronously encryption algorithm of color image RGB components based on extraction plaintext information coupled multi-chaotic pixel shuffle.Firstly, it performed the operation of the color image RGB pixels sep-aration, binarization and vectorization to get the three vectors of RGB, and regrouped theses vectors to obtain the permutation matrix of RGB pixels interaction.Then it extracted the image information to control iterative processes of four super-chaotic systems for making the random sequence associated with the plaintext, and used these random sequences to encrypt the permu-tation matrix by shuffling column-wise and row-wise.Simulation results show that compared with other color image encryption algorithm, this algorithm has higher security and larger key space, as well as strong key sensitive performance.This algorithm has high security, and it can meet the actual engineering requirements.
Synchronized chaotic phase masks for encrypting and decrypting images
Rueda, Edgar; Vera, Carlos A.; Rodríguez, Boris; Torroba, Roberto
2008-12-01
This paper presents an alternative to secure exchange of encrypted information through public open channels. Chaotic encryption introduces a security improvement by an efficient masking of the message with a chaotic signal. Message extraction by an authorized end user is done using a synchronization procedure, thus allowing a continuous change of the encrypting and decrypting keys. And optical implementation with a 4f optical encrypting architecture is suggested. Digital simulations, including the effects of missing data, corrupted data and noise addition are shown. These results proof the consistency of the proposal, and demonstrate a practical way to operate with it.
Data Encryption and Decryption Algorithm Using Hamming Code and Arithmetic Operations
Kurapati Sundar Teja
2015-08-01
Full Text Available This paper explains the implementation of data encryption and decryption algorithm using hamming code and arithmetic operations with the help of Verilog HDL. As the days are passing the old algorithms are not remained so strong cryptanalyst are familiar with them. Hamming code is one of forward error correcting code which has got many applications. In this paper hamming code algorithm was discussed and the implementation of it was done with arithmetic operations. For high security some arithmetic operations are added with hamming code process. A 3-bit data will be encrypted as 14-bit and using decryption process again we will receives 3-bit original data. The implemented design was tested on Spartan3A FPGA kit.
A Secure Implementation of a Symmetric Encryption Algorithm in White-Box Attack Contexts
Yang Shi
2013-01-01
Full Text Available In a white-box context, an adversary has total visibility of the implementation of the cryptosystem and full control over its execution platform. As a countermeasure against the threat of key compromise in this context, a new secure implementation of the symmetric encryption algorithm SHARK is proposed. The general approach is to merge several steps of the round function of SHARK into table lookups, blended by randomly generated mixing bijections. We prove the soundness of the implementation of the algorithm and analyze its security and efficiency. The implementation can be used in web hosts, digital right management devices, and mobile devices such as tablets and smart phones. We explain how the design approach can be adapted to other symmetric encryption algorithms with a slight modification.
Optical color image encryption based on an asymmetric cryptosystem in the Fresnel domain
Chen, Wen; Chen, Xudong
2011-08-01
In recent years, optical color image encryption has attracted much attention in the information security field. Some approaches, such as digital holography, have been proposed to encrypt color images, but the previously proposed methods are developed based on optical symmetric cryptographic strategies. In this paper, we apply an optical asymmetric cryptosystem for the color image encryption instead of conventional symmetric cryptosystems. A phase-truncated strategy is applied in the Fresnel domain, and multiple-wavelength and indexed image methods are further employed. The security of optical asymmetric cryptosystem is also analyzed during the decryption. Numerical results are presented to demonstrate the feasibility and effectiveness of the proposed optical asymmetric cryptosystem for color image encryption.
Ensemble Of Blowfish With Chaos Based S Box Design For Text And Image Encryption
Jeyamala Chandrasekaran
2011-08-01
Full Text Available The rapid and extensive usage of Internet in the present decade has put forth information security as an utmost concern. Most of the commercial transactions taking place over the Internet involves a wide variety of data including text, images, audio and video. With the increasing use of digital techniques for transmitting and storing Multimedia data, the fundamental issue of protecting the confidentiality, integrity and authenticity of the information poses a major challenge for security professionals and hassled to the major developments in Cryptography . In cryptography, an S-Box (Substitution-box is a basic componentof symmetric key algorithms, which performs substitution and is typically used to make the relationship between the key and the cipher text non linear and most of the symmetric key algorithms like DES, Blowfish makes use of S boxes. This paper proposes a new method for design of S boxes based on chaos theory. Chaotic equations are popularly known for its randomness, extreme sensitivity to initial conditions and ergodicity. The modified design has been tested with blowfish algorithm which has no effective crypt analysis reported against its design till date because of its salient design features including the key dependant s boxes and complex key generation process. However every new key requires pre-processing equivalent to encrypting about 4 kilobytes of text, which is very slow compared to other block ciphers and it prevents its usage in memory limited applications and embedded systems. The modified design of S boxesmaintains the non linearity [3] [5] and key dependency factors of S boxes with a major reduction in time complexity of generation of S boxes and P arrays. The algorithm has been implemented and the proposed design has been analyzed for size of key space, key sensitivity and Avalanche effect. Experimental results on text and Image Encryption show that the modified design of key generation continues to offer the same
Chen, Tinghuan; Zhang, Meng; Wu, Jianhui; Yuen, Chau; Tong, You
2016-10-01
Because of simple encryption and compression procedure in single step, compressed sensing (CS) is utilized to encrypt and compress an image. Difference of sparsity levels among blocks of the sparsely transformed image degrades compression performance. In this paper, motivated by this difference of sparsity levels, we propose an encryption and compression approach combining Kronecker CS (KCS) with elementary cellular automata (ECA). In the first stage of encryption, ECA is adopted to scramble the sparsely transformed image in order to uniformize sparsity levels. A simple approximate evaluation method is introduced to test the sparsity uniformity. Due to low computational complexity and storage, in the second stage of encryption, KCS is adopted to encrypt and compress the scrambled and sparsely transformed image, where the measurement matrix with a small size is constructed from the piece-wise linear chaotic map. Theoretical analysis and experimental results show that our proposed scrambling method based on ECA has great performance in terms of scrambling and uniformity of sparsity levels. And the proposed encryption and compression method can achieve better secrecy, compression performance and flexibility.
Rajput, Sudheesh K.; Nishchal, Naveen K.
2017-04-01
We propose a novel security scheme based on the double random phase fractional domain encoding (DRPE) and modified Gerchberg-Saxton (G-S) phase retrieval algorithm for securing two images simultaneously. Any one of the images to be encrypted is converted into a phase-only image using modified G-S algorithm and this function is used as a key for encrypting another image. The original images are retrieved employing the concept of known-plaintext attack and following the DRPE decryption steps with all correct keys. The proposed scheme is also used for encryption of two color images with the help of convolution theorem and phase-truncated fractional Fourier transform. With some modification, the scheme is extended for simultaneous encryption of gray-scale and color images. As a proof-of-concept, simulation results have been presented for securing two gray-scale images, two color images, and simultaneous gray-scale and color images.
Mathematical description of the two-dimensional Gabor transform. Application to image encryption
Perez, Ronal; Vilardy, Juan M.; Torres, Cesar O.
2017-01-01
Information security with optical processing, such as the double random phase encoding and the Gabor transform (GT) has been investigated by various researchers. We present a two-dimensional (2-D) generalization of the one-dimensional GT. This 2-D GT is applied to encrypt digital images in this paper. The scaling factors of the GT can be used as new keys, providing a new encryption system with a high security characteristics. This method can encrypt and protect the information of the digital images with a high security for information processing systems.
Authentication and Encryption in GSM and 3GUMTS: An Emphasis on Protocols and Algorithms
Elouafiq, Ali
2012-01-01
Mobile communication touches every aspect of our life, it become one of the major dependencies that the 21st Century civilizations rely on. Thereby, security is a major issue that should be targeted by communication technologies. In this paper we will target authentication and encryption in GSM and 3G/UMTS. In order to understand clearly how things work, we will start by presenting the architecture of each network, its major components, its authentication algorithms, protocols used, and KASUMI Block Cipher.
Halving the dimension of a single image to be encrypted optically to avoid data expansion
Yi, Jiawang; Tan, Guanzheng
2016-06-01
When directly applying optical transforms, such as fractional Fourier transform (FrFT), to a single image or real image (input image), the resulting image will become complex-valued, which leads to the doubling of data volume. This data expansion problem can be found in many existing single-image optical encryption schemes. We propose a folding technique to offset the data expansion by constructing a complex input image of half size. And we devise an optical single-image encryption scheme based on double FrFTs, in which this technique together with compressed sensing can bring about the possible maximum compression of encrypted images. Moreover, the chaos-based random circular shift for scrambling is introduced to enhance security. The chaotic random signum matrix is also tried as the measurement matrix, and it displays a good performance. Simulation results demonstrate the validity and security of the proposed scheme.
A joint asymmetric watermarking and image encryption scheme
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.
Design and Implementation on the Image Encryption of Mobile Communication System%移动通信的图像加密系统设计与实现
万玉晴
2015-01-01
针对智能手机图像的加密应用需求与目前台式加密系统不能很好地适用于移动终端平台等问题，本文设计了一套适用于智能手机的图像加密系统，结合基于混沌算法的图像加密技术，提出了适用于移动端应用的低配置、快速实现图像加密的技术方法。实验结果表明，系统采用的并行多线程技术路线，可以提高大像素图像的加解密效率三倍以上，为智能手机的实时图像加密提供了一种可实现解决方案。%This article presents an image encryption system for smart phones that can solve the problems such as the application requirements of image encryption of smart phones and the current desktop encryption systems are not quite suitable for mobile terminal platform. It propose a technical method with low allocation and fast image encryption for mobile application with the use of image encryption technology based on chaos algorithm. The experiment result shows that the parallel multithreading technical strategy adopted by the system can improve over three times encryption and decryption efficiency of large pixel images. So it can provide a realizable solution for the real-time image encryption of smart phones.
Singh, Hukum
2016-12-01
A cryptosystem for securing image encryption is considered by using double random phase encoding in Fresnel wavelet transform (FWT) domain. Random phase masks (RPMs) and structured phase masks (SPMs) based on devil's vortex toroidal lens (DVTL) are used in spatial as well as in Fourier planes. The images to be encrypted are first Fresnel transformed and then single-level discrete wavelet transform (DWT) is apply to decompose LL,HL, LH and HH matrices. The resulting matrices from the DWT are multiplied by additional RPMs and the resultants are subjected to inverse DWT for the encrypted images. The scheme is more secure because of many parameters used in the construction of SPM. The original images are recovered by using the correct parameters of FWT and SPM. Phase mask SPM based on DVTL increases security that enlarges the key space for encryption and decryption. The proposed encryption scheme is a lens-less optical system and its digital implementation has been performed using MATLAB 7.6.0 (R2008a). The computed value of mean-squared-error between the retrieved and the input images shows the efficacy of scheme. The sensitivity to encryption parameters, robustness against occlusion, entropy and multiplicative Gaussian noise attacks have been analysed.
An RGB Image Encryption Supported by Wavelet-based Lossless Compression
Ch. Samson
2012-09-01
Full Text Available In this paper we have proposed a method for an RGB image encryption supported by lifting scheme based lossless compression. Firstly we have compressed the input color image using a 2-D integer wavelet transform. Then we have applied lossless predictive coding to achieve additional compression. The compressed image is encrypted by using Secure Advanced Hill Cipher (SAHC involving a pair of involutory matrices, a function called Mix( and an operation called XOR. Decryption followed by reconstruction shows that there is no difference between the output image and the input image. The proposed method can be used for efficient and secure transmission of image data.
Sui, Liansheng; Xu, Minjie; Tian, Ailing
2017-04-01
A novel optical image encryption scheme is proposed based on quick response code and high dimension chaotic system, where only the intensity distribution of encoded information is recorded as ciphertext. Initially, the quick response code is engendered from the plain image and placed in the input plane of the double random phase encoding architecture. Then, the code is encrypted to the ciphertext with noise-like distribution by using two cascaded gyrator transforms. In the process of encryption, the parameters such as rotation angles and random phase masks are generated as interim variables and functions based on Chen system. A new phase retrieval algorithm is designed to reconstruct the initial quick response code in the process of decryption, in which a priori information such as three position detection patterns is used as the support constraint. The original image can be obtained without any energy loss by scanning the decrypted code with mobile devices. The ciphertext image is the real-valued function which is more convenient for storing and transmitting. Meanwhile, the security of the proposed scheme is enhanced greatly due to high sensitivity of initial values of Chen system. Extensive cryptanalysis and simulation have performed to demonstrate the feasibility and effectiveness of the proposed scheme.
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.
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
A novel chaotic map and an improved chaos-based image encryption scheme.
Zhang, Xianhan; Cao, Yang
2014-01-01
In this paper, we present a novel approach to create the new chaotic map and propose an improved image encryption scheme based on it. Compared with traditional classic one-dimensional chaotic maps like Logistic Map and Tent Map, this newly created chaotic map demonstrates many better chaotic properties for encryption, implied by a much larger maximal Lyapunov exponent. Furthermore, the new chaotic map and Arnold's Cat Map based image encryption method is designed and proved to be of solid robustness. The simulation results and security analysis indicate that such method not only can meet the requirement of imagine encryption, but also can result in a preferable effectiveness and security, which is usable for general applications.
RESEARCH ON FAST IMAGE ENCRYPTION METHOD FOR MOBILE TERMINALS%移动终端的图像快速加密方法研究
赵戈; 万玉晴
2015-01-01
According to the requirements of intelligent terminals of mobile Internet in image encryption,this article puts forward the four selection principles in regard to encryption approaches for images of mobile terminals based on analysing the traditional methods of image pixel positions scrambling and pixel greyscale value encryption by transformation,and based on these principles we design the encryption algorithm with dual image keys and dual scrambling which combines the Arnold conversion and the chaotic sequence encryption.Meanwhile,in order to improve computing speed of encryption and decryption,and to realise fast image encryption and decryption of mobile terminals,based on periodic verification and theoretical derivation of Arnold conversion,we derive a fast look-up table method for image encryption and decryption matrix of mobile terminals.It is proved by application that the algorithm can satisfy the requirement of transaction processing in image encryption of mobile terminals.%针对移动互联网智能终端的图像加密需求，在对传统的图像像素位置置乱以及像素灰度值变换加密等方法的分析与实验基础上，提出移动终端图像加密方法的四项选择原则，并按此原则设计Arnold变换和混沌序列加密相结合的图像双重密钥双重置乱加密算法。同时，为了提高加解密运算速度，实现移动终端快速图像加解密工作，在基于对Arnold变换的周期性验证和理论推导，得出移动终端的图像加解密矩阵的快速查表法。应用证明，该算法能满足事务处理对移动终端图像加密的需求。
A Novel Bit-level Image Encryption Method Based on Chaotic Map and Dynamic Grouping
张国基; 沈彦
2012-01-01
In this paper,a novel bit-level image encryption method based on dynamic grouping is proposed.In the proposed method,the plain-image is divided into several groups randomly,then permutation-diffusion process on bit level is carried out.The keystream generated by logistic map is related to the plain-image,which confuses the relationship between the plain-image and the cipher-image.The computer simulation results of statistical analysis,information entropy analysis and sensitivity analysis show that the proposed encryption method is secure and reliable enough to be used for communication application.
A Double Chaotic Layer Encryption Algorithm for Clinical Signals in Telemedicine.
Murillo-Escobar, M A; Cardoza-Avendaño, L; López-Gutiérrez, R M; Cruz-Hernández, C
2017-04-01
Recently, telemedicine offers medical services remotely via telecommunications systems and physiological monitoring devices. This scheme provides healthcare delivery services between physicians and patients conveniently, since some patients can not attend the hospital due to any reason. However, transmission of information over an insecure channel such as internet or private data storing generates a security problem. Therefore, authentication, confidentiality, and privacy are important challenges in telemedicine, where only authorized users should have access to medical or clinical records. On the other hand, chaotic systems have been implemented efficiently in cryptographic systems to provide confidential and privacy. In this work, we propose a novel symmetric encryption algorithm based on logistic map with double chaotic layer encryption (DCLE) in diffusion process and just one round of confusion-diffusion for the confidentiality and privacy of clinical information such as electrocardiograms (ECG), electroencephalograms (EEG), and blood pressure (BP) for applications in telemedicine. The clinical signals are acquired from PhysioBank data base for encryption proposes and analysis. In contrast with recent schemes in literature, we present a secure cryptographic algorithm based on chaos validated with the most complete security analysis until this time. In addition, the cryptograms are validated with the most complete pseudorandomness tests based on National Institute of Standards and Technology (NIST) 800-22 suite. All results are at MATLAB simulations and all them show the effectiveness, security, robustness, and the potential use of the proposed scheme in telemedicine.
Improvement of Networked Control Systems Performance Using a New Encryption Algorithm
Seyed Ali Mesbahifard
2014-07-01
Full Text Available Networked control systems are control systems which controllers and plants are connected via telecommunication network. One of the most important challenges in networked control systems is the problem of network time delay. Increasing of time delay may affect on control system performance extremely. Other important issue in networked control systems is the security problems. Since it is possible that unknown people access to network especially Internet, the probability of terrible attacks such as deception attacks is greater, therefore presentation of methods which could decrease time delay and increase system immunity are desired. In this paper a symmetric encryption with low data volume against deception attacks is proposed. This method has high security and low time delay rather than the other encryption algorithms and could improve the control system performance against deception attacks.
Syed Mahamud Hossein
2013-09-01
Full Text Available Storing, transmitting and security of DNA sequences are well known research challenge. The problem has got magnified with increasing discovery and availability of DNA sequences. We have represent DNA sequence compression algorithm based on Dynamic Look Up Table (DLUT and modified Huffman technique. DLUT consists of 43(64 bases that are 64 sub-stings, each sub-string is of 3 bases long. Each sub-string are individually coded by single ASCII code from 33(! to 96(` and vice versa. Encode depends on encryption key choose by user from four base pair {a,t.g and c}and decode also require decryption key provide by the encoded user. Decoding must require authenticate input for encode the data. The sub-strings are combined into a Dynamic Look up Table based pre-coding routine. This algorithm is tested on reverse; complement & reverse complement the DNA sequences and also test on artificial DNA sequences of equivalent length. Speed of encryption and security levels are two important measurements for evaluating any encryption system. Due to proliferate of ubiquitous computing system, where digital contents are accessible through resource constraint biological database security concern is very important issue. A lot of research has been made to find an encryption system which can be run effectively in those biological databases. Information security is the most challenging question to protect the data from unauthorized user. The proposed method may protect the data from hackers. It can provide the three tier security, in tier one is ASCII code, in tier two is nucleotide (a,t,g and c choice by user and tier three is change of label or change of node position in Huffman Tree. Compression of the genome sequences will help to increase the efficiency of their use. The greatest advantage of this algorithm is fast execution, small memory occupation and easy implementation. Since the program to implement the technique have been written originally in the C language
A self-adaptive image encryption scheme with half-pixel interchange permutation operation
Ye, Ruisong; Liu, Li; Liao, Minyu; Li, Yafang; Liao, Zikang
2017-01-01
A plain-image dependent image encryption scheme with half-pixel-level swapping permutation strategy is proposed. In the new permutation operation, a pixel-swapping operation between four higher bit-planes and four lower bit-planes is employed to replace the traditional confusion operation, which not only improves the conventional permutation efficiency within the plain-image, but also changes all the pixel gray values. The control parameters of generalized Arnold map applied for the permutation operation are related to the plain-image content and consequently can resist chosen-plaintext and known-plaintext attacks effectively. To enhance the security of the proposed image encryption, one multimodal skew tent map is applied to generate pseudo-random gray value sequence for diffusion operation. Simulations have been carried out thoroughly to demonstrate that the proposed image encryption scheme is highly secure thanks to its large key space and efficient permutation-diffusion operations.
MEGHANA A. HASAMNIS
2012-05-01
Full Text Available An Advanced Standard Encryption Algorithm (AES is widely used in modern consumer electronicproducts for security. The IEEE 802.15.4 Low-Rate wireless sensor networks also use AES algorithm wherelow power consumption is the priority. To reduce the time taken for encryption of huge data, the algorithm hasto be implemented in hardware. To meet the requirement for low area the algorithm has to be implemented insoftware. Hence, a balance has to be achieved between hardware and software implementations in terms of areaand speed, so as to improve the overall performance of the system. Also with the co-design methodology totalthermal power dissipation is reduced. In this paper, 128 bit AES algorithm is implemented with hardware incombination with software using Altera NIOS II Processor platform. Altera’s Quartus II environment is used fordesign of the system. Cyclone II FPGA is used as a development platform. Software program is written in C language. NIOS II ntegrated Development Environment (IDE is used to integrate hardware and software together. By adopting hardware / software co-design methodology for implementation of AES, results show that a onsiderable improvement in speed can be achieved as compared to software only approach. Further, the significant reduction in area is achieved as compared to hardware only approach. By the approach of co-design an optimized design in terms of speed and area is achieved and also the thermal power dissipation is reduced
A New Loss-Tolerant Image Encryption Scheme Based on Secret Sharing and Two Chaotic Systems
Li Li
2012-04-01
Full Text Available In this study, we propose an efficient loss-tolerant image encryption scheme that protects both confidentiality and loss-tolerance simultaneously in shadow images. In this scheme, we generate the key sequence based on two chaotic maps and then encrypt the image during the sharing phase based on Shamir’s method. Experimental results show a better performance of the proposed scheme for different images than other methods from human vision. Security analysis confirms a high probability to resist both brute-force and collusion attacks.
郭祖华; 王辉
2015-01-01
Current chaotic map cryptographies are commonly difficult to balance high computation efficiency and high security and cannot meet the real-time transmission requirement of internet as well.In light of these shortcomings, we design the synchronised pseudo-random number generator and the parallelised masking technology, and introduce periodic boundary conditions, according to 2D chaotic map and nearest-neighbouring coupled map lattices we derive the coupling model of the algorithm proposed in the paper, and present an image encryption algorithm in which the 2D piecewise nonlinear chaotic map couples the nearest-neighbouring coupled map lattices.Through synchronised pseudo-random number generator we generate the initial conditions and parameters of the proposed algorithm, and then according to the coupling model we derive a group of pseudo-random numbers by iterating the initial values; finally, we use these pseudo-random numbers to carry out bidirectional encryption on plaintext image based on encryption transformation function, and use S-box to substitute the encryption elements, and conduct the masking process.Simulation results show that compared with current chaotic cryptography, the proposed algorithm has higher security and computation efficiency;and can meet the real-time transmission requirement of internet as well.%针对当前的混沌映射加密算法普遍难以兼顾高计算效率和高安全性,无法满足互联网实时性传输要求等不足. 设计了伪随机数同步生成器和并行化掩蔽技术;并引入周期性边界条件,根据2D混沌映射与最邻近耦合映像格子推导出耦合模型,提出一种2D分段非线性混沌映射耦合最邻近耦合映像格子的图像加密算法. 通过伪随机数同步生成器生成算法的初始条件与参数,然后根据该耦合模型迭代初始值,得到一组伪随机数;最后利用该伪随机数根据加密变换函数对明文图像进行双向加密,利
A Wheel-Switch Selective Image Encryption Scheme Using Spatiotemporal Chaotic System
Wang, Xing-Yuan; Bao, Xue-Mei
2014-02-01
In this paper, we propose a novel selective image encryption scheme using a one-way coupled map lattice (CML) consisting of logistic maps and a selector constructed by two variants of a cyclic shift register (VCSR). The initial conditions and the coupling constant of CML in our scheme are influenced by all the contents of the plain image. Moreover, the selector is closely related to the nonencrypted part of the plain image. In addition, we select only a portion of image data to encrypt via a wheel-switch scheme governed by the selector. Users can select an appropriate proportion to encrypt the plain image for their different demands of security and efficiency. Experimental results and theoretical analysis show that the cryptosystem is effective and can resist various typical attacks.
A Novel Image Encryption Scheme Based on Multi-orbit Hybrid of Discrete Dynamical System
Ruisong Ye
2014-10-01
Full Text Available A multi-orbit hybrid image encryption scheme based on discrete chaotic dynamical systems is proposed. One generalized Arnold map is adopted to generate three orbits for three initial conditions. Another chaotic dynamical system, tent map, is applied to generate one pseudo-random sequence to determine the hybrid orbit points from which one of the three orbits of generalized Arnold map. The hybrid orbit sequence is then utilized to shuffle the pixels' positions of plain-image so as to get one permuted image. To enhance the encryption security, two rounds of pixel gray values' diffusion is employed as well. The proposed encryption scheme is simple and easy to manipulate. The security and performance of the proposed image encryption have been analyzed, including histograms, correlation coefficients, information entropy, key sensitivity analysis, key space analysis, differential analysis, etc. All the experimental results suggest that the proposed image encryption scheme is robust and secure and can be used for secure image and video communication applications.
Transmission Error and Compression Robustness of 2D Chaotic Map Image Encryption Schemes
Michael Gschwandtner
2007-11-01
Full Text Available This paper analyzes the robustness properties of 2D chaotic map image encryption schemes. We investigate the behavior of such block ciphers under different channel error types and find the transmission error robustness to be highly dependent on on the type of error occurring and to be very different as compared to the effects when using traditional block ciphers like AES. Additionally, chaotic-mixing-based encryption schemes are shown to be robust to lossy compression as long as the security requirements are not too high. This property facilitates the application of these ciphers in scenarios where lossy compression is applied to encrypted material, which is impossible in case traditional ciphers should be employed. If high security is required chaotic mixing loses its robustness to transmission errors and compression, still the lower computational demand may be an argument in favor of chaotic mixing as compared to traditional ciphers when visual data is to be encrypted.
Transmission Error and Compression Robustness of 2D Chaotic Map Image Encryption Schemes
Gschwandtner Michael
2007-01-01
Full Text Available This paper analyzes the robustness properties of 2D chaotic map image encryption schemes. We investigate the behavior of such block ciphers under different channel error types and find the transmission error robustness to be highly dependent on on the type of error occurring and to be very different as compared to the effects when using traditional block ciphers like AES. Additionally, chaotic-mixing-based encryption schemes are shown to be robust to lossy compression as long as the security requirements are not too high. This property facilitates the application of these ciphers in scenarios where lossy compression is applied to encrypted material, which is impossible in case traditional ciphers should be employed. If high security is required chaotic mixing loses its robustness to transmission errors and compression, still the lower computational demand may be an argument in favor of chaotic mixing as compared to traditional ciphers when visual data is to be encrypted.
Chatterjee, Monish R.; Almehmadi, Fares S.
2015-01-01
Secure information encryption via acousto-optic (AO) chaos with profiled optical beams indicates substantially better performance in terms of system robustness. This paper examines encryption of static and time-varying (video) images onto AO chaotic carriers using Gaussian-profile beams with diffracted data numerically generated using transfer functions. The use of profiled beams leads to considerable improvement in the encrypted signal. While static image encryption exhibits parameter tolerances within about +/-10% for uniform optical beams, profiled beams reduce the tolerance to less than 1%, thereby vastly improving both the overall security of the transmitted information as well as the quality of the image retrieval.
Optical image encryption based on multi-beam interference and common vector decomposition
Chen, Linfei; He, Bingyu; Chen, Xudong; Gao, Xiong; Liu, Jingyu
2016-02-01
Based on multi-beam interference and common vector decomposition, we propose a new method for optical image encryption. In encryption process, the information of an original image is encoded into n amplitude masks and n phase masks which are regarded as a ciphertext and many keys. In decryption process, parallel light irradiates the amplitude masks and phase masks, then passes through lens that takes place Fourier transform, and finally we obtain the original image at the output plane after interference. The security of the encryption system is also discussed in the paper, and we find that only when all the keys are correct, can the information of the original image be recovered. Computer simulation results are presented to verify the validity and the security of the proposed method.
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.
RSA加密算法中MPI的应用%Application of MPI in RSA encryption algorithm
陆玉阳
2015-01-01
RSA加密算法在进行复杂判断和大数运算时,计算时间往往花费较多,对计算机的运行速度、存储容量等方面具有较高的要求.MPI能够提供较快的数值计算和数据处理能力,提供高性能并行计算.该文通过在RSA加密算法中MPI的应用,通过实践证明MPI并行计算可以改进RSA算法,提高加密速度、减少容量需求等.%RSA encryption algorithm in the complex judgment and operation of large Nbers, calculating the time tend to spend more, the computer run faster, have higher requirements in terms of storage capacity. MPI provides fast Nerical calculation and data processing capability, providing high performance parallel computing. Based on RSA encryption algorithm in application of MPI, MPI parallel computing can improve the RSA algorithm proved by practice, increase speed, reduce capacity requirements, and so on.
Cryptanalysis and improvement of a digital image encryption method with chaotic map lattices
Wang Xing-Yuan; Liu Lin-Tao
2013-01-01
A digital image encryption scheme using chaotic map lattices has been proposed recently.In this paper,two fatal flaws of the cryptosystem are pointed out.According to these two drawbacks,cryptanalysts could recover the plaintext by applying the chosen plaintext attack.Therefore,the proposed cryptosystem is not secure enough to be used in the image transmission system.Experimental results show the feasibility of the attack.As a result,we make some improvements to the encryption scheme,which can completely resist our chosen plaintext attack.
Enayatifar, Rasul; Sadaei, Hossein Javedani; Abdullah, Abdul Hanan; Lee, Malrey; Isnin, Ismail Fauzi
2015-08-01
Currently, there are many studies have conducted on developing security of the digital image in order to protect such data while they are sending on the internet. This work aims to propose a new approach based on a hybrid model of the Tinkerbell chaotic map, deoxyribonucleic acid (DNA) and cellular automata (CA). DNA rules, DNA sequence XOR operator and CA rules are used simultaneously to encrypt the plain-image pixels. To determine rule number in DNA sequence and also CA, a 2-dimension Tinkerbell chaotic map is employed. Experimental results and computer simulations, both confirm that the proposed scheme not only demonstrates outstanding encryption, but also resists various typical attacks.
线性移位寄存器在图像加密中的应用%The Application in Image Encryption by Line Feedback Shift Register
荆锐; 朱平; 杨恒欢; 冯涛
2011-01-01
图像加密技术作为数字信息保护的一种有效手段，随着信息技术的发展，人们对其安全性的要求越来越高。讨论了关于线性移位寄存器（LFSR）在图像加密中的应用。本算法先采用LFSR算法产生伪混沌比特密钥流，将该密钥流作为随机值映射算法和加密算法的初始参数。随机值映射算法取其中较高位的密钥流，生成置乱序列用于图像像素的位置置乱。另一组密钥流作为加密序列可对图像的像素值进行加密。实验结果表明该方法运算速度快，通过随机值映射算法产生的伪随机置乱和加密序列具有很强的可操作性、保密性，而且截取伪混沌比特密钥流的位数也可作为密钥存在。%For digital information protection, image encryption is an effective technology. As the development of information technology, people also need more and more security on image encryption. This thesis discussed the application in image encryption by line feedback shift register. At first the system generated the initial pseudo-chaos bit key stream by LSFR. The key stream becomed the initial parameter of the random value mapped scrambling algorithm and chaos encryption algorithm. Mapping the image with the mapped stream which was generated by the random value mapped scrambling algorithm with the higher digital key stream, then encrypted the image with the encrypted stream which was generated by another key stream. The result shows this system runs lastly. The pseudo-random mapped stream and pseudo-encrypted stream that were generated by the random value scrambling algorithm both had a strong operational, confidentiality. Also the chosen pseudo-chaos bit key stream can become the keywords.
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.
A NEW TECHNIQUE BASED ON CHAOTIC STEGANOGRAPHY AND ENCRYPTION TEXT IN DCT DOMAIN FOR COLOR IMAGE
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.
Towards Symbolic Encryption Schemes
Ahmed, Naveed; Jensen, Christian D.; Zenner, Erik
2012-01-01
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....
Synchronization of spatiotemporal semiconductor lasers and its application in color image encryption
Banerjee, S.; Rondoni, L.; Mukhopadhyay, S.; Misra, A. P.
2011-05-01
Optical chaos is a topic of current research characterized by high-dimensional nonlinearity which is attributed to the delay-induced dynamics, high bandwidth and easy modular implementation of optical feedback. In light of these facts, which add enough confusion and diffusion properties for secure communications, we explore the synchronization phenomena in spatiotemporal semiconductor laser systems. The novel system is used in a two-phase colored image encryption process. The high-dimensional chaotic attractor generated by the system produces a completely randomized chaotic time series, which is ideal in the secure encoding of messages. The scheme thus illustrated is a two-phase encryption method, which provides sufficiently high confusion and diffusion properties of chaotic cryptosystem employed with unique data sets of processed chaotic sequences. In this novel method of cryptography, the chaotic phase masks are represented as images using the chaotic sequences as the elements of the image. The scheme drastically permutes the positions of the picture elements. The next additional layer of security further alters the statistical information of the original image to a great extent along the three-color planes. The intermediate results during encryption demonstrate the infeasibility for an unauthorized user to decipher the cipher image. Exhaustive statistical tests conducted validate that the scheme is robust against noise and resistant to common attacks due to the double shield of encryption and the infinite dimensionality of the relevant system of partial differential equations.
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.
Multidimensional Z-Matrix with Control Parameters and Its Applications in Image Encryption
ZHAO Liang; LIAO Xiao-Feng; XIANG Tao; XIAO Di
2009-01-01
An n-dimensional Z-matrix with control parameters is presented,and its periodicity and chaos are testified.Experimental results show that the proposed Z-matrix has a long period and changeable periodicity with different dimensions.Some examples of image encryption with a Z-matrix of different dimensions are listed for demonstrating its appfications.
CHEN Lin-Fei; ZHAO Dao-Mu
2006-01-01
@@ We propose a new method to add different images together by optical implementation that is realized by the multi-exposure based on fractional Fourier transform hologram. Partial image fusion is proposed and realized by this method. Multiple images encryption can also be implemented by the multi-exposure of the hologram based on fractional Fourier transform. Computer simulations prove that this method is valid.
Kasem, Hossam M.; Nasr, Mohamed E.; Sallam, Elsayed A.; Abd El-Samie, F. E.
2011-10-01
Image transmission takes place as an important research branch in multimedia broadcasting communication systems in the last decade. Our paper presents image transmission over a FFT-OFDM (Fast Fourier Transform Orthogonal Frequency Division Multiplexing). The need for encryption techniques increase with the appearance of the expression which said that our world became small village, and the use of image application such as conference and World Wide Web which increase rapidly in recent years. Encryption is an effective method for protecting the transmitted data by converting it into a form being invisible over transmission path and visible in receiver side. This paper presents a new hybrid encryption technique based on combination of Backer maps and logistic map. This proposed technique aims to increase PSNR and reduce the noise in the received image. The encryption is done by shuffling the positions of a pixel image using two dimensional Baker maps then encrypt using XOR operation with logistic map to generate cipher image over orthogonal frequency multiplexing (OFDM). The encryption approach adopted in this paper is based on chaotic Baker maps because the encoding and decoding steps in this approach are simple and fast enough for HDTV applications. The experimental results reveal the superiority of the proposed chaotic based image encryption technique using two logistic maps and two dimensional Backer map over normal Backer map.
Cheremkhin, Pavel A.; Evtikhiev, Nikolay N.; Krasnov, Vitaly V.; Molodtsov, Dmitriy Y.; Rodin, Vladislav G.; Shifrina, Anna V.
2016-04-01
The majority of existing methods of optical encryption use not only light intensity distribution, easily registered with photosensors, but also its phase distribution. This provides best encryption strength for fixed quantities of elements and phase levels in a mask. Downsides are holographic registration scheme used in order to register not only light intensity distribution but also its phase distribution and speckle noise occurring due to coherent illumination. That factors lead to very poor decryption quality when it comes from computer simulations to optical implementations. Method of optical encryption with spatially incoherent illumination does not have drawbacks inherent to coherent systems, however, as only light intensity distribution is considered, mean value of image to be encrypted is always above zero which leads to intensive zero spatial frequency peak in image spectrum. Therefore, in case of spatially incoherent illumination, image spectrum, as well as encryption key spectrum, cannot be white. If encryption is based on convolution operation, no matter coherent light used or not, Fourier spectrum amplitude distribution of encryption key should overlap Fourier spectrum amplitude distribution of image to be encrypted otherwise loss of information is unavoidable. Another factor affecting decrypted image quality is original image spectrum. Usually, most part of image energy is concentrated in area of low frequencies. Consequently, only this area in encrypted image contains information about original image, while other areas contain only noise. We propose to use additional encoding of input scene to increase size of the area containing useful information. This provides increase of signal-to-noise ratio in encrypted image and consequentially increases quality of decrypted images. Results of computer simulations of test images optical encryption with spatially incoherent illumination and additional input amplitude masks are presented.
A Reversible Image Steganographic Algorithm Based on Slantlet Transform
Sushil Kumar
2013-07-01
Full Text Available In this paper we present a reversible imagesteganography technique based on Slantlet transform (SLTand using advanced encryption standard (AES method. Theproposed method first encodes the message using two sourcecodes, viz., Huffman codes and a self-synchronizing variablelength code known as, T-code. Next, the encoded binarystring is encrypted using an improved AES method. Theencrypted data so obtained is embedded in the middle andhigh frequency sub-bands, obtained by applying 2-level ofSLT to the cover-image, using thresholding method. Theproposed algorithm is compared with the existing techniquesbased on wavelet transform. The Experimental results showthat the proposed algorithm can extract hidden message andrecover the original cover image with low distortion. Theproposed algorithm offers acceptable imperceptibility,security (two-layer security and provides robustness againstGaussian and Salt-n-Pepper noise attack.
An authenticated image encryption scheme based on chaotic maps and memory cellular automata
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.
System for Information Encryption Implementing Several Chaotic Orbits
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
Color image encryption based on hybrid hyper-chaotic system and cellular automata
Yaghouti Niyat, Abolfazl; Moattar, Mohammad Hossein; Niazi Torshiz, Masood
2017-03-01
This paper proposes an image encryption scheme based on Cellular Automata (CA). CA is a self-organizing structure with a set of cells in which each cell is updated by certain rules that are dependent on a limited number of neighboring cells. The major disadvantages of cellular automata in cryptography include limited number of reversal rules and inability to produce long sequences of states by these rules. In this paper, a non-uniform cellular automata framework is proposed to solve this problem. This proposed scheme consists of confusion and diffusion steps. In confusion step, the positions of the original image pixels are replaced by chaos mapping. Key image is created using non-uniform cellular automata and then the hyper-chaotic mapping is used to select random numbers from the image key for encryption. The main contribution of the paper is the application of hyper chaotic functions and non-uniform CA for robust key image generation. Security analysis and experimental results show that the proposed method has a very large key space and is resistive against noise and attacks. The correlation between adjacent pixels in the encrypted image is reduced and the amount of entropy is equal to 7.9991 which is very close to 8 which is ideal.
A parallel block-based encryption schema for digital images using reversible cellular automata
Faraoun Kamel Mohamed
2014-06-01
Full Text Available We propose a novel images encryption schema based on reversible one-dimensional cellular automata. Contrasting to the sequential operating mode of several existing approaches, the proposed one is fully parallelizable since the encryption/decryption tasks can be executed using multiple processes running independently for the same single image. The parallelization is made possible by defining a new RCA-based construction of an extended pseudorandom permutation that takes a nonce as a supplementary parameter. The defined PRP exploit the chaotic behavior and the high initial condition's sensitivity of the RCAs to ensure perfect cryptographic security properties. Results of various experiments and analysis show that high security and execution performances can be achieved using the approach, and furthermore, it provides the ability to perform a selective area decryption since any part of the ciphered-image can be deciphered independently from others, which is very useful for real time applications.
Synchronization of spatiotemporal semiconductor lasers and its application in color image encryption
Banerjee, S; Mukhopadhyay, S; Misra, A P; 10.1016/j.optcom.2010.12.077
2011-01-01
Optical chaos is a topic of current research characterized by high-dimensional nonlinearity which is attributed to the delay-induced dynamics, high bandwidth and easy modular implementation of optical feedback. In light of these facts, which adds enough confusion and diffusion properties for secure communications, we explore the synchronization phenomena in spatiotemporal semiconductor laser systems. The novel system is used in a two-phase colored image encryption process. The high-dimensional chaotic attractor generated by the system produces a completely randomized chaotic time series, which is ideal in the secure encoding of messages. The scheme thus illustrated is a two-phase encryption method, which provides sufficiently high confusion and diffusion properties of chaotic cryptosystem employed with unique data sets of processed chaotic sequences. In this novel method of cryptography, the chaotic phase masks are represented as images using the chaotic sequences as the elements of the image. The scheme dras...
基于函数展开与超混沌系统的图像加密%Image Encryption Based on Function Expansion and Hyperchaotic System
迟春见; 于万波; 魏小鹏
2011-01-01
In order to protect the security of a digital image effectively, this paper proposes an image encryption algorithm based on wavelet expansion function and hyperchaotic system. The pixel locations of the image are scrambled with a wavelet function, and the relationship between the original image and the encrypted image is disrupted with hyper-chaos system. The many parameters are inserted in four-step Runge-Kutta method in which chaos sequence of hyper--chaos system is gotten, to expand the space of parameter. Simulation exporimental result show that the random behavior of gray value distribution of the encrypted image is better and the method can defends attacks.%为有效保护数字图像的安全,提出一种基于小波展开函数与超混沌系统的数字图像加密算法.利用小波展开函数对网像进行置乱,通过超混沌系统扰乱原图像与加密图像之间的关系.在求解超混沌系统混沌序列的四阶Runge-Kutta公式中,插入多个参数以扩大参数空间.模拟实验结果表明,加密后图像灰度值分布伪随机性较好.
A New Image Encryption Scheme Based on Dynamic S-Boxes and Chaotic Maps
Rehman, Atique Ur; Khan, Jan Sher; Ahmad, Jawad; Hwang, Soeng Oun
2016-03-01
Substitution box is a unique and nonlinear core component of block ciphers. A better designing technique of substitution box can boost up the quality of ciphertexts. In this paper, a new encryption method based on dynamic substitution boxes is proposed via using two chaotic maps. To break the correlation in an original image, pixels values of the original plaintext image are permuted row- and column-wise through random sequences. The aforementioned random sequences are generated by 2-D Burgers chaotic map. For the generation of dynamic substitution boxes, Logistic chaotic map is employed. In the process of diffusion, the permuted image is divided into blocks and each block is substituted via different dynamic substitution boxes. In contrast to conventional encryption schemes, the proposed scheme does not undergo the fixed block cipher and hence the security level can be enhanced. Extensive security analysis including histogram test is applied on the proposed image encryption technique. All experimental results reveal that the proposed scheme has a high level of security and robustness for transmission of digital images on insecure communication channels.
Multimedia encryption and watermarking encryption and watermarking
Furht, Borko; Socek, Daniel
2006-01-01
""Multimedia Encryption and Watermarking"" presents a comprehensive survey of contemporary multimedia encryption and watermarking techniques, which enable a secure exchange of multimedia intellectual property. Part I, Digital Rights Management (DRM) for Multimedia, introduces DRM concepts and models for multimedia content protection, and presents the key players. Part II, Multimedia Cryptography, provides an overview of modern cryptography, with the focus on modern image, video, speech, and audio encryption techniques. This book also provides an advanced concept of visual and audio sharing tec
Security of image encryption scheme based on multi-parameter fractional Fourier transform
Zhao, Tieyu; Ran, Qiwen; Yuan, Lin; Chi, Yingying; Ma, Jing
2016-10-01
Recently, multi-parameter fractional Fourier transform (MPFRFT) has been widely applied in the optics cryptosystem, which has attracted more and more researchers' attention. However, in further study we find a serious security problem on the MPFRFT which is the multi-choice of decryption key corresponding to an encryption key. The existence of multi-decryption-key hinders the application of this algorithm. We present a new generalized fractional Fourier transform, which can overcome the problem and enlarge the key space. The simulation results show that the proposed algorithm has higher security and key sensitivity.
Optical image encryption with silhouette removal based on interference and phase blend processing
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.
Application of coupled map lattice with parameter q in image encryption
Hao, Zhang; Xing-yuan, Wang; Si-wei, Wang; Kang, Guo; Xiao-hui, Lin
2017-01-01
In this paper, a novel coupled map lattice (CML) with parameter q is applied to image encryption to get higher security. The CML with parameter q is provided with Euler method and Adams-Bashforth-Moulton predictor-corrector method. In the new CML, dynamical properties are improved because the coupled strength can decrease the periodic dynamical behaviors which are caused by finite-precision. What's more, the CML changes system parameters from one-dimensional to two-dimensional. Two-dimensional parameters and coupling strengths provide researchers a possibility to improve the performance in image encryption. Finally, from numerical simulation results, it can be found that the CML improves the effectiveness and security.
Meghana Hasamnis
2012-06-01
Full Text Available Embedded system design is becoming complex day by day, combined with reduced time-to-market deadlines. Due to the constraints and complexity in the design of embedded systems, it incorporates hardware / software co-design methodology. An embedded system is a combination of hardware and software parts integrated together on a common platform. A soft-core processor which is a hardware description language (HDL model of a specific processor (CPU can be customized for any application and can be synthesized for FPGA target. This paper gives a comparative analysis of the development environment for embedded systems using LEON 3 and NIOS II Processor, both soft core processors. LEON3 is an open source processor and NIOS II is a commercial processor. Case study under consideration is Rijindael’s Encryption Algorithm (AES. It is a standard encryption algorithm used to encrypt huge bulk of data and for security. Using the co-design methodology the algorithm is implemented on two different platforms. One using the open source and other using the commercial processor and the comparative results of the two different platforms is stated in terms of its performance parameters. The algorithm is partitioned in hardware and software parts and integrated on a common platform.
VLSI Implementation of Encryption and Decryption System Using Hamming Code Algorithm
Fazal Noorbasha
2014-04-01
Full Text Available In this paper, we propose an optimized VLSI implementation of encryption and decryption system using hamming code algorithm. In the present field of communication has got many applications, and in every field the data is encoded at the transmitter and transfer on a communication channel and receive at the receiver after data is decoded. During the broadcast of data it might get degraded because of some noise on the channel. So it is crucial for the receiver to have some function which can recognize and correct the error in the received data. Hamming code is one of such forward error correcting code which has got many applications. In this paper the algorithm for hamming code is discussed and then implementation of it in verilog is done to get the results. Hamming code is an upgrading over parity check method. Here a code is implemented in verilog in which 4-bit of information data is transmitted with 3-redundancy bits. In order to do that the proposed method uses a Field Programmable Gate Array (FPGA. It is known that FPGA provides quick implementation and fast hardware verification. It gives facilities of reconfiguring the design construct unlimited number of times. The HDL code is written in verilog, Gate Level Circuit and Layout is implemented in CMOS technology.
Medical Images Watermarking Algorithm Based on Improved DCT
Yv-fan SHANG
2013-12-01
Full Text Available Targeting at the incessant securities problems of digital information management system in modern medical system, this paper presents the robust watermarking algorithm for medical images based on Arnold transformation and DCT. The algorithm first deploys the scrambling technology to encrypt the watermark information and then combines it with the visual feature vector of the image to generate a binary logic series through the hash function. The sequence as taken as keys and stored in the third party to obtain ownership of the original image. Having no need for artificial selection of a region of interest, no capacity constraint, no participation of the original medical image, such kind of watermark extracting solves security and speed problems in the watermark embedding and extracting. The simulation results also show that the algorithm is simple in operation and excellent in robustness and invisibility. In a word, it is more practical compared with other algorithms
Wang, Qu; Guo, Qing; Zhou, Jinyun
2013-12-20
We propose a multiple-image encryption scheme, based on polarized light encoding and the interference principle of phase-only masks (POMs), in the Fresnel-transform (FrT) domain. In this scheme, each secret image is converted into an intensity image by polarized light encoding, where a random key image and a pixilated polarizer with random angles are employed as keys. The intensity encrypted images produced by different secret images are convolved together and then inverse Fresnel-transformed. Phase and amplitude truncations are used to generate the asymmetric decryption keys. The phase-truncated inverse FrT spectrum is sent into an interference-based encryption (IBE) system to analytically obtain two POMs. To reduce the transmission and storage load on the keys, the chaotic mapping method is employed to generate random distributions of keys for encryption and decryption. One can recover all secret images successfully only if the corresponding decryption keys, the mechanism of FrTs, and correct chaotic conditions are known. The inherent silhouette problem can be thoroughly resolved by polarized light encoding in this proposal, without using any time-consuming iterative methods. The entire encryption and decryption process can be realized digitally, or in combination with optical means. Numerical simulation results are presented to verify the effectiveness and performance of the proposed scheme.
A Fresnelet-Based Encryption of Medical Images using Arnold Transform
Muhammad Nazeer
2013-04-01
Full Text Available Medical images are commonly stored in digital media and transmitted via Internet for certain uses. If a medical information image alters, this can lead to a wrong diagnosis which may create a serious health problem. Moreover, medical images in digital form can easily be modified by wiping off or adding small pieces of information intentionally for certain illegal purposes. Hence, the reliability of medical images is an important criterion in a hospital information system. In this paper, the Fresnelet transform is employed along with appropriate handling of the Arnold transform and the discrete cosine transform to provide secure distribution of medical images. This method presents a new data hiding system in which steganography and cryptography are used to prevent unauthorized data access. The experimental results exhibit high imperceptibility for embedded images and significant encryption of information images.
Comment: Cryptanalysis of an image encryption scheme based on the Hill cipher
Cheng-qing LI; Dan ZHANG; Guan-rong CHEN
2008-01-01
This paper studies the security of an image encryption scheme based on the Hill cipher (Ismail et al.,2006) and reports its following problems:(1) There is a simple necessary and sufficient condition that makes a number of secret keys invalid;(2) It is insensitive to the change of the secret key;(3) It is insensitive to the change of the plain-image;(4) It can be broken with only one known/chosen plaintext;(5) It has some other minor defects.The proposed cryptanalysis discourages any use of the scheme in practice.
Lang, Jun
2012-07-01
In recent years, a number of methods have been proposed in the literature for the encryption of two-dimensional information by use of the fractional Fourier transform, but most of their encryptions are complex value and need digital hologram technique to record their encrypted information, which is inconvenience for digital transmission. In this paper, we first propose a novel reality-preserving multiple-parameter fractional Fourier transform which share real-valuedness outputs as well as most of the properties required for a fractional transform. Then we propose a new approach for image encryption based on the real-valuedness of the reality-preserving multiple-parameter fractional Fourier transform and the decorrelation property of chaotic maps in order to meet the requirements of the secure image transmission. In the proposed scheme, the image is encrypted by juxtaposition of sections of the image in the reality-preserving multiple-parameter fractional Fourier domains and the alignment of sections is determined by chaotic logistic maps. Numerical simulations are performed to demonstrate that the proposed method is reliable and more robust to blind decryption than several existing methods.
Secure Image Encryption Based On a Chua Chaotic Noise Generator
A. S. Andreatos
2013-10-01
Full Text Available This paper presents a secure image cryptography telecom system based on a Chua's circuit chaotic noise generator. A chaotic system based on synchronised Master–Slave Chua's circuits has been used as a chaotic true random number generator (CTRNG. Chaotic systems present unpredictable and complex behaviour. This characteristic, together with the dependence on the initial conditions as well as the tolerance of the circuit components, make CTRNGs ideal for cryptography. In the proposed system, the transmitter mixes an input image with chaotic noise produced by a CTRNG. Using thresholding techniques, the chaotic signal is converted to a true random bit sequence. The receiver must be able to reproduce exactly the same chaotic noise in order to subtract it from the received signal. This becomes possible with synchronisation between the two Chua's circuits: through the use of specific techniques, the trajectory of the Slave chaotic system can be bound to that of the Master circuit producing (almost identical behaviour. Additional blocks have been used in order to make the system highly parameterisable and robust against common attacks. The whole system is simulated in Matlab. Simulation results demonstrate satisfactory performance, as well as, robustness against cryptanalysis. The system works with both greyscale and colour jpg images.
An image encryption scheme based on the MLNCML system using DNA sequences
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.
Liang, Jinyang; Gao, Liang; Hai, Pengfei; Li, Chiye; Wang, Lihong V
2015-10-27
Compressed ultrafast photography (CUP), a computational imaging technique, is synchronized with short-pulsed laser illumination to enable dynamic three-dimensional (3D) imaging. By leveraging the time-of-flight (ToF) information of pulsed light backscattered by the object, ToF-CUP can reconstruct a volumetric image from a single camera snapshot. In addition, the approach unites the encryption of depth data with the compressed acquisition of 3D data in a single snapshot measurement, thereby allowing efficient and secure data storage and transmission. We demonstrated high-speed 3D videography of moving objects at up to 75 volumes per second. The ToF-CUP camera was applied to track the 3D position of a live comet goldfish. We have also imaged a moving object obscured by a scattering medium.
An Efficient Image Encryption Scheme Based on a Peter De Jong Chaotic Map and a RC4 Stream Cipher
Hanchinamani, Gururaj; Kulkarni, Linganagouda
2015-09-01
Security is a vital issue in communication and storage of the images and encryption is one of the ways to ensure the security. This paper proposes an efficient image encryption scheme based on a Peter De Jong chaotic map and a RC4 stream cipher. A Peter De Jong map is employed to determine the initial keys for the RC4 stream generator and also during permutation stage. The RC4 stream generator is utilized to generate the pseudo random numbers for the pixel value rotation and diffusion operations. Each encryption round is comprised of three stages: permutation, pixel value rotation and diffusion. The permutation is based on scrambling the rows and columns, in addition, circular rotations of the rows and columns in alternate orientations. The second stage circularly rotates each and every pixel value by utilizing M × N pseudo random numbers. The last stage carries out the diffusion twice by scanning the image in two different ways. Each of the two diffusions accomplishes the diffusion in two orientations (forward and backward) with two previously diffused pixels and two pseudo random numbers. The security and performance of the proposed method is assessed thoroughly by using key space, statistical, differential, entropy and performance analysis. Moreover, two rounds of the call to the encrypt function provide the sufficient security. The experimental results show that the proposed encryption scheme is computationally fast with high security.
Research on image self-recovery algorithm based on DCT
Shengbing Che
2010-06-01
Full Text Available Image compression operator based on discrete cosine transform was brought up. A securer scrambling locational operator was put forward based on the concept of anti-tamper radius. The basic idea of the algorithm is that it first combined image block compressed data with eigenvalue of image block and its offset block, then scrambled or encrypted and embeded them into least significant bit of corresponding offset block. This algorithm could pinpoint tampered image block and tampering type accurately. It could recover tampered block with good image quality when tamper occured within the limits of the anti-tamper radius. It could effectively resist vector quantization and synchronous counterfeiting attacks on self-embedding watermarking schemes.
A Chaos-based Image Encryption Scheme Using 3D Skew Tent Map and Coupled Map Lattice
Ruisong Ye
2012-02-01
Full Text Available This paper proposes a chaos-based image encryption scheme where one 3D skew tent map with three control parameters is utilized to generate chaotic orbits applied to scramble the pixel positions while one coupled map lattice is employed to yield random gray value sequences to change the gray values so as to enhance the security. Experimental results have been carried out with detailed analysis to demonstrate that the proposed image encryption scheme possesses large key space to resist brute-force attack and possesses good statistical properties to frustrate statistical analysis attacks. Experiments are also performed to illustrate the robustness against malicious attacks like cropping, noising, JPEG compression.
Azoug, Seif Eddine; Bouguezel, Saad
2016-01-01
In this paper, a novel opto-digital image encryption technique is proposed by introducing a new non-linear preprocessing and using the multiple-parameter discrete fractional Fourier transform (MPDFrFT). The non-linear preprocessing is performed digitally on the input image in the spatial domain using a piecewise linear chaotic map (PLCM) coupled with the bitwise exclusive OR (XOR). The resulting image is multiplied by a random phase mask before applying the MPDFrFT to whiten the image. Then, a chaotic permutation is performed on the output of the MPDFrFT using another PLCM different from the one used in the spatial domain. Finally, another MPDFrFT is applied to obtain the encrypted image. The parameters of the PLCMs together with the multiple fractional orders of the MPDFrFTs constitute the secret key for the proposed cryptosystem. Computer simulation results and security analysis are presented to show the robustness of the proposed opto-digital image encryption technique and the great importance of the new non-linear preprocessing introduced to enhance the security of the cryptosystem and overcome the problem of linearity encountered in the existing permutation-based opto-digital image encryption schemes.
A STRING ENCRYPTION ALGORITHM BASED ON CHAOS THEORY%一种基于混沌理论的字符串加密算法
陈绍钧
2011-01-01
提出一种基于混沌理论的字符串加密算法.通过应用混沌理论的"随机过程"产生随机密钥和随机干扰字符串,使用密钥对明文字符串进行异或(XOR)加密,再将运算后的密文同密钥、干扰字符串按照一定规则组合构成完整的混沌密文.该算法具有运算量小、灵活性强、加密强度高的特点.%The paper presents a string encryption algorithm based on chaos theory. By applying chaos theory' s “random process”, the random key and random interference string are generated. The encryption key encodes plaintext strings with XOR operation; then composes the computed encryption text with the encryption key and interference string together according to designated rules to build a complete chaos encryption text. The algorithm bears such features as fewer calculations, greater flexibilities and stronger encryption.
Deepan, B; Quan, C; Wang, Y; Tay, C J
2014-07-10
In this paper, a new multiple-image encryption and decryption technique that utilizes the compressive sensing (CS) concept along with a double-random phase encryption (DRPE) has been proposed. The space multiplexing method is employed for integrating multiple-image data. The method, which results in a nonlinear encryption system, is able to overcome the vulnerability of classical DRPE. The CS technique and space multiplexing are able to provide additional key space in the proposed method. A numerical experiment of the proposed method is implemented and the results show that the proposed method has good accuracy and is more robust than classical DRPE. The proposed system is also employed against chosen-plaintext attacks and it is found that the inclusion of compressive sensing enhances robustness against the attacks.
Mona F. M. Mursi
2014-11-01
Full Text Available Robust and secure transmission strategy for high quality image through wireless networks is considered a great challenge. However, the majority of encrypted image transmission schemes don't consider well the effect of bit errors occurring during transmission. These errors are due to the factors that affect the information such as noise and multipath propagation. That should be handled by an efficient channel coding scheme. Our proposed scheme is based on combining hybrid chaotic encryption, which is based on two-dimensional chaotic maps which is utilized for data security, with an error correction technique based on the Low Density Parity Check (LDPC code. The LDPC is employed as channel coding for data communication in order to solve the problem of the channel’s limited bandwidth and improve throughput. Simulation results show that the proposed scheme achieves a high degree of robustness against channel impairments and wide varieties of attacks as wells as improved reliability of the wireless channel. In addition, LDPC is utilized for error correction in order to solve the limitations of wireless channels.
Decryption of pure-position permutation algorithms
赵晓宇; 陈刚; 张亶; 王肖虹; 董光昌
2004-01-01
Pure position permutation image encryption algorithms, commonly used as image encryption investigated in this work are unfortunately frail under known-text attack. In view of the weakness of pure position permutation algorithm,we put forward an effective decryption algorithm for all pure-position permutation algorithms. First, a summary of the pure position permutation image encryption algorithms is given by introducing the concept of ergodic matrices. Then, by using probability theory and algebraic principles, the decryption probability of pure-position permutation algorithms is verified theoretically; and then, by defining the operation system of fuzzy ergodic matrices, we improve a specific decryption al-gorithm. Finally, some simulation results are shown.
FORTRAN Algorithm for Image Processing
Roth, Don J.; Hull, David R.
1987-01-01
FORTRAN computer algorithm containing various image-processing analysis and enhancement functions developed. Algorithm developed specifically to process images of developmental heat-engine materials obtained with sophisticated nondestructive evaluation instruments. Applications of program include scientific, industrial, and biomedical imaging for studies of flaws in materials, analyses of steel and ores, and pathology.
A self-cited pixel summation based image encryption algorithm
Ye, Guo-Dong; Huang, Xiao-Ling; Zhang, Leo Yu; Wang, Zheng-Xia
2017-01-01
Not Available Project supported by the National Natural Science Foundation of China (Grant Nos. 61602124, 61273021, 11526057, and 11301091), the Natural Science Foundation of Guangdong Province, China (Grant Nos. 2016A030310333, 2015A030313614, and 2015A030313620), the Science & Technology Planning Projects of Zhanjiang City, China (Grant Nos. 2015B01098 and 2015B01051), the Project Foundation of Chongqing Municipal Education Committee of China (Grant No. KJ1500501), the Program for Scientific Research Start-up Funds of Guangdong Ocean University of China, and the Special Funding Program for Excellent Young Scholars of Guangdong Ocean University of China.
Alfalou, A; Brosseau, C; Abdallah, N; Jridi, M
2013-04-01
We introduce a double optimization procedure for spectrally multiplexing multiple images. This technique is adapted from a recently proposed optical setup implementing the discrete cosine transformation (DCT). The new analysis technique is a combination of spectral fusion based on the properties of DCT, specific spectral filtering, and quantization of the remaining encoded frequencies using an optimal number of bits. Spectrally multiplexing multiple images defines a first level of encryption. A second level of encryption based on a real key image is used to reinforce encryption. A set of numerical simulations and a comparison with the well known JPEG (Joint Photographic Experts Group) image compression standard have been carried out to demonstrate the improved performances of this method. The focus here will differ from the method of simultaneous fusion, compression, and encryption of multiple images (SFCE) [Opt. Express 19, 24023 (2011)] in the following ways. Firstly, we shall be concerned with optimizing the compression rate by adapting the size of the spectral block to each target image and decreasing the number of bits required to encode each block. This size adaptation is achieved by means of the root-mean-square (RMS) time-frequency criterion. We found that this size adaptation provides a good tradeoff between bandwidth of spectral plane and number of reconstructed output images. Secondly, the encryption rate is improved by using a real biometric key and randomly changing the rotation angle of each block before spectral fusion. By using a real-valued key image we have been able to increase the compression rate of 50% over the original SFCE method. We provide numerical examples of the effects for size, rotation, and shifting of DCT-blocks which play noteworthy roles in the optimization of the bandwidth of the spectral plane. Inspection of the results for different types of attack demonstrates the robustness of our procedure.
Uncertain state encryption algorithm based on linear congruential sequence%基于线性同余的不定态结果加密算法
王思乐; 卢素魁; 杨文柱
2012-01-01
The traditional encryption algorithms is often more complex and difficult to master, complex algorithms tend to greatly increase the complexity of the program, the same encryption algorithm results are the same and reduce the resistance to crack the encryption result ability. After the linear congruential sequences data on study characteristics as well as in practice after long time exploration and detection based on linear congruential sequences, this paper puts forward a practical method of encryption, simple, easy to realize; as far as possible without loss of intensity of encryption cases to improve the encryption speed, at the same time, the same input encryption results the output of different, some extent increase the anti crack capacity.%传统的加密算法往往比较复杂而难以掌握,复杂的算法往往大大增加程序的复杂度,同一算法加密结果不变又降低了加密结果的抗破解能力.经过对线性同余序列数据特征的研究以及在实践中经过长时间摸索与检测,基于线性同余序列提出了一种实用的加密方法,简单、容易实现;在尽量不损失加密强度的情况下提高了加解密速度,同时,同一输入得到的加密结果输出不同,一定程度上增强了抗破解能力.
Hardware stream cipher with controllable chaos generator for colour image encryption
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.
Noise reduction in selective computational ghost imaging using genetic algorithm
Zafari, Mohammad; Ahmadi-Kandjani, Sohrab; Kheradmand, Reza
2017-03-01
Recently, we have presented a selective computational ghost imaging (SCGI) method as an advanced technique for enhancing the security level of the encrypted ghost images. In this paper, we propose a modified method to improve the ghost image quality reconstructed by SCGI technique. The method is based on background subtraction using genetic algorithm (GA) which eliminates background noise and gives background-free ghost images. Analyzing the universal image quality index by using experimental data proves the advantage of this modification method. In particular, the calculated value of the image quality index for modified SCGI over 4225 realization shows an 11 times improvement with respect to SCGI technique. This improvement is 20 times in comparison to conventional CGI technique.
Hanzhong Zheng
2014-01-01
Full Text Available A systematic methodology is developed for multi-images encryption and decryption and field programmable gate array (FPGA embedded implementation by using single discrete time chaotic system. To overcome the traditional limitations that a chaotic system can only encrypt or decrypt one image, this paper initiates a new approach to design n-dimensional (n-D discrete time chaotic controlled systems via some variables anticontrol, which can achieve multipath drive-response synchronization. To that end, the designed n-dimensional discrete time chaotic controlled systems are used for multi-images encryption and decryption. A generalized design principle and the corresponding implementation steps are also given. Based on the FPGA embedded hardware system working platform with XUP Virtex-II type, a chaotic secure communication system for three digital color images encryption and decryption by using a 7D discrete time chaotic system is designed, and the related system design and hardware implementation results are demonstrated, with the related mathematical problems analyzed.
关于加密数据的填充方式的研究%Study on mode and padding in encryption algorithm
樊志英
2014-01-01
Aiming at the interoperability of encryption and decryption in different platform environment,the two important parameters which are encryption mode and padding method used in encryption algorithm are elaborated in combination with en-cryption function Cipher provided by the encryption extended service on the Java platform. The rules in the encryption mode are discussed in detail,and their advantages,disadvantages and application scope are compared. The difference between the plain-text data before and after padding is analyzed in depth,which can narrow the range of encryption and decryption parameters for Java and other platforms,and can effectively solve the interaction problem between encryption and decryption.%针对不同平台环境下加解密的互通问题，结合Java平台下密码扩展服务SunJCE提供的加密类函数Cipher，对加密算法中使用到的明文填充方式进行阐述。详细介绍加密时明文数据的常用填充规则，并比较数据填充前后的区别，深入分析SunJCE支持的填充方式与常用填充规则的对应性，并对RSA算法的加解密互通进行了测试。加密数据填充方式的研究，为Java平台与其他平台之间加解密参数的约定提供了依据。双方只有遵循相同的填充和去填充规则，才能实现有效的解密。
Boosting of Image Denoising Algorithms
Romano, Yaniv; Elad, Michael
2015-01-01
In this paper we propose a generic recursive algorithm for improving image denoising methods. Given the initial denoised image, we suggest repeating the following "SOS" procedure: (i) (S)trengthen the signal by adding the previous denoised image to the degraded input image, (ii) (O)perate the denoising method on the strengthened image, and (iii) (S)ubtract the previous denoised image from the restored signal-strengthened outcome. The convergence of this process is studied for the K-SVD image ...
Liansheng, Sui; Bei, Zhou; Xiaojuan, Ning; Ailing, Tian
2016-01-11
A novel multiple-image encryption scheme using the nonlinear iterative phase retrieval algorithm in the gyrator transform domain under the illumination of an optical vortex beam is proposed. In order to increase the randomness, the chaotic structured phase mask based on the logistic map, Fresnel zone plate and radial Hilbert mask is proposed. With the help of two chaotic phase masks, each plain image is encoded into two phase-only masks that are considered as the private keys by using the iterative phase retrieval process in the gyrator domain. Then, the second keys of all plain images are modulated into the ciphertext, which has the stationary white noise distribution. Due to the use of the chaotic structured phase masks, the problem of axis alignment in the optical setup can easily be solved. Two private keys are directly relative to the plain images, which makes that the scheme has high resistance against various potential attacks. Moreover, the use of the vortex beam that can integrates more system parameters as the additional keys into one phase mask can improve the security level of the cryptosystem, which makes the key space enlarged widely. Simulation results are given to verify the feasibility and robustness of the proposed encryption scheme.
An 3-DES Key Encryption Method Generated by Iris Image%由虹膜图像生成3-DES密钥的加密方法
曾明权; 卞燕山; 赵刚
2012-01-01
介绍虹膜生物特征生成密钥的过程，在此基础上，采用3-DES算法对机密图像进行加密。图像加密方案中，将生物特征技术引入其中，成功获得了所需要的比特位，通过对128比特位进行处理，得到了3-DES算法所需要的密钥，其试验结果表明加密的结果良好，达到了预期的目的。%The progresses that biological characteristics of iris are untilized to generate key are presented, based on which 3-DES algorithm is employed for confidential image encryption. The biological characteristics are introduced into image encryption methods and the needed bits stream are archived. After disposing those 128 bits stream, we attain the key for 3-DES algorithm. Experiments show that the enctyption result is good and prospective target is realized.
Speckle imaging algorithms for planetary imaging
Johansson, E. [Lawrence Livermore National Lab., CA (United States)
1994-11-15
I will discuss the speckle imaging algorithms used to process images of the impact sites of the collision of comet Shoemaker-Levy 9 with Jupiter. The algorithms use a phase retrieval process based on the average bispectrum of the speckle image data. High resolution images are produced by estimating the Fourier magnitude and Fourier phase of the image separately, then combining them and inverse transforming to achieve the final result. I will show raw speckle image data and high-resolution image reconstructions from our recent experiment at Lick Observatory.
肖本海; 郑莹娜; 龙建明; 郭盼盼
2015-01-01
随着二维码技术广泛应用于电子票务、银行支票、电子保单等多个领域，二维码的信息泄露和信息篡改等安全问题日益突出。为提高二维码内部信息的安全性能，从对二维码内部信息加密和二维码信息防篡改俩个角度来提高。基于Visual Studio 2008 C#平台，设计了一种采用SHA512哈希函数和Rijndael加密算法混合加密的方法，该方法利用Rijndael加密和SHA512数字签名等技术，对Rijndael第一次加密密钥系统随机分配，并对系统随机分配密钥采用二次Rijndael加密防护方法，并通过SHA512对二维码内部信息防篡改校验，达到对二维码信息及其加密密钥的安全保护。在生成QR二维码之前实现了信息加密，并从系统构架、算法原理和实现及安全性能等多个方面进行了测试和分析。分析表明此方法提高了二维码信息的安全性能，达到对密钥高效管理和对信息的多重保护，而在加密后密文信息容量较明文信息有所增加。%With the QR code technology being widely applied in electronic ticketing, bank checks, E-commerce and other fields, many safety problems have emerged, such as information leakage and data tampering. Based on Visual Studio 2008 c platform, the method with Rijndael random variable and random keys secondary Rijndael encryption protection is proposed using Rijndael encryption and SHA512 digital signature technology. This paper presents a novel design of information security before generating QR code. The encryption principle, algorithm and implementation, safety performance of the proposed method are discussed. Also corresponding testing and analysis are provided to verify the feasibility of the proposed algorithm. Results have proved that the information safety performance of QR code is greatly increased with the encryption algorithm, the efficient management and the multiple- protection to a key. This just causes a smaller increase
Wang, Qu; Guo, Qing; Lei, Liang
2013-06-01
We present a novel method for double image encryption that is based on amplitude-phase mixed encoding and multistage random phase encoding in gyrator transform (GT) domains. In the amplitude-phase mixed encoding operation, a random binary distribution matrix is defined to mixed encode two primitive images to a single complex-valued image, which is then encrypted into a stationary white noise distribution by the multistage phase encoding with GTs. Compared with the earlier methods that uses fully phase encoding, the proposed method reduces the difference between two primitive images in key space and sensitivity to the GT orders. The primitive images can be recovered exactly by applying correct keys with initial conditions of chaotic system, the GT orders and the pixel scrambling operation. Numerical simulations demonstrate that the proposed scheme has considerably high security level and certain robustness against data loss and noise disturbance.
Wang, Xiaogang; Zhao, Daomu
2013-09-01
A nonlinear color and grayscale images cryptosystem based on phase-truncated fractional Fourier transform and optical superposition principle is proposed. In order to realize simultaneous encryption of color and grayscale images, each grayscale image is first converted into two phase masks by using an optical coherent superposition, one of which is treated as a part of input information that will be fractional Fourier transformed while the other in the form of a chaotic random phase mask (CRPM) is used as a decryption key. For the purpose of optical performance, all the processes are performed through three channels, i.e., red, green, and blue. Different from most asymmetric encryption methods, the decryption process is designed to be linear for the sake of effective decryption. The encryption level of a double random phase encryption based on phase-truncated Fourier transform is enhanced by extending it into fractional Fourier domain and the load of the keys management and transmission is lightened by using CRPMs. The security of the proposed cryptosystem is discussed and computer simulation results are presented to verify the validity of the proposed method.
New Comprehensive Study to Assess Comparatively the QKD, XKMS, KDM in the PKI encryption algorithms
Bilal Bahaa Zaidan
2009-11-01
Full Text Available Protecting data is a very old art and wide use since the Egyptian when they identify the 1st encryption method in this world, the spiciest people categorize protecting data under computer forensic and others locate it under network security, cryptography methods are the backbone of this art, nowadays many of new techniques for the attacker's beings develops, a lot of methods for information protecting start dropping down such as RSA and stander encryption methods, in the same time a new methods has been appeared such as Quantum cryptography, the new methods has faced problems in the key distribution or key management and some time such as RSA there is a function may estimate the keys, In this paper we will make a comparative study between the key management distribution methods, in fact we will talk about QKD Encryption in the fiber optic area vice verse the KDM in the normal networks, for instant there are two known methods, KDM "Diffi- Hellman" and XKMS.
Novel Fast Encryption Algorithms for Multimedia Transmission over Mobile WiMax Networks
M.A. Mohamed
2012-11-01
Full Text Available Security support is mandatory for any communication networks. For wireless systems, security support is even more important to protect the users as well as the network. Since wireless medium is available to all, the attackers can easily access the network and the network becomes more vulnerable for the user and the network service provider. Worldwide Interoperability for Microwave Access (WiMax is going to be an emerging wireless technology nowadays. With the increasing popularity of Broadband internet, wireless networking market is thriving. In the IEEE 802.16e, security has been considered as the main issue during the design of the protocol. However, security mechanism of WiMax still remains an open research field. WiMax is relatively a new technology not deployed widely to justify the evidence of threats, risk and vulnerability in real situations. In this paper, a research is described three proposed chaos encryption techniques for multimedia transmission over Mobile WiMax physical and MAC layers. At first a global overview of the technology WiMax is given followed by an explanation of traditional encryption techniques used in WiMax. Then the proposed encryption techniques are presented with its chaos systems. Next, these techniques will be applied to different multimedia contents to compare between them and traditional techniques such as AES, IDEA, Blowfish and DES.
A Fingerprint Image Encryption Scheme Based on Hyperchaotic Rössler Map
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.
Testing a Variety of Encryption Technologies
Henson, T J
2001-04-09
Review and test speeds of various encryption technologies using Entrust Software. Multiple encryption algorithms are included in the product. Algorithms tested were IDEA, CAST, DES, and RC2. Test consisted of taking a 7.7 MB Word document file which included complex graphics and timing encryption, decryption and signing. Encryption is discussed in the GIAC Kickstart section: Information Security: The Big Picture--Part VI.
A chaos-based digital image encryption scheme with an improved diffusion strategy.
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.
Huffman和S-DES混合加密算法的研究%Analysis of Huffman and S-DES of Mixed Encryption Algorithm
郑静; 王腾
2014-01-01
In contrast to the existing common encryption software and classical cryptography, combined with the present situa-tion and development of the current text encryption, this paper will be based on dynamic Huffman coding and S-DES algo-rithm, make up for the shortcomings of the two, achieve the best effect on text information encryption.%在对比现有的加密软件和古典密码学常见的加密算法后，结合文本加密的现状及发展趋势，该文将基于动态Huff-man编码和S-DES算法相结合，弥补两者的缺点，达到对文本信息的最佳加密及解密效果。
Optical image encryption based on real-valued coding and subtracting with the help of QR code
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.
智能计量箱控制器加密通信算法研究%Study on Encrypted Communication Algorithm for Smart Metering-Box Controller
张庆辉; 刘勇
2012-01-01
针对智能计量箱的防窃电功能，文中研究了计量箱控制器的加密通信算法，并在加密的基础上制定了特定的通信协议及身份认证方法，其中着重研究了DES对称加密算法，通过密钥协商、对称加密、随机数加密等多种手段，使控制器与每个电子钥匙的通信都采用不同的密钥加密，且每一帧数据在加密后都不相同，链路中传输的数据都是完全随机的，即使被截获也无从破解，最后对加密通信进行了编程实现和结果验证。%For the anti-theft function of smart metering box, the eficrypted communication algorithm for smart metering-box controller is researched, and based on encryption, the special communication protocols and identity authentication methods are developed. The DES symmetric encryption algorithm is emphatically studied. Finally, the encrypted communication is programmed and realized, and the experiment results indicate the correctness and feasibility of the encrypted communication algorithm.
Spread spectrum image data hiding in the encrypted discrete cosine transform coefficients
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.
Sui, Liansheng; Duan, Kuaikuai; Liang, Junli
2015-05-01
A new discrete fractional transform defined by the fractional order, periodicity and vector parameters is presented, which is named as the discrete multiple-parameter fractional angular transform. Based on this transform and two-coupled logistic map, a double-image encryption scheme is proposed. First, an enlarged image is obtained by connecting two plaintext images sequentially and scrambled by using a chaotic permutation process, in which the sequences of chaotic pairs generated by using the two-coupled logistic map. Then, the scrambled enlarged image is decomposed into two new components. Second, a chaotic random phase mask is generated based on the logistic map, with which one of two components is converted to the modulation phase mask. Another component is encoded into an interim matrix with the help of the modulation phase mask. Finally, the two-dimensional discrete multiple-parameter fractional angular transform is performed on the interim matrix to obtain the ciphertext with stationary white noise distribution. The proposed encryption scheme has an obvious advantage that no phase keys are used in the encryption and decryption process, which is convenient to key management. Moreover, the security of the cryptosystem can be enhanced by using extra parameters such as initial values of chaos functions, fractional orders and vector parameters of transform. Simulation results and security analysis verify the feasibility and effectiveness of the proposed scheme.
基于手指静脉特征图像的加密研究%Research on Encryption Based on Finger Vein Feature Image
陈暄
2016-01-01
Information security in the mobile Internet is currently a hotspot in researches.Starting from encryption of finger vein image, this paper first extracts characteristics of the finger vein image,and gets the size of vein image through establishing image smoother as well as the collected image of vein features through selecting the darkness area and characteristic features.Then,this paper adopts the function based on wavelet,Android mapping,the quadratic Logistic mapping and Baker transform to encrypt the vein image.Conduct experiment to com-pare the correlation analysis and differential attack analysis,and the results show that algorithm in this paper is safe and costs less time,so it is suitable to promote it in the mobile Internet.%移动互联下的信息安全是目前研究的热门，提出从手指静脉图像的加密出发，首先对手指静脉图像的特征进行了提取，通过构建图像平滑器来获得静脉图像的大小，明暗区域的选择和特征图像的加强来获得采集后的静脉特征图像，其次对静脉图像采用基于小波基函数，Arnold映射，二次Logistic 映射和Baker变换的混合加密方式对进行加密；在相关系分析和差分攻击分析等方面实验比较，说明算法具有很好的安全性和低耗时性，能够完全适应在移动互联环境中推广。
A chaotic block cipher algorithm for image cryptosystems
Amin, Mohamed; Faragallah, Osama S.; Abd El-Latif, Ahmed A.
2010-11-01
Recently, many scholars have proposed chaotic cryptosystems in order to promote communication security. However, there are a number of major problems detected in some of those schemes such as weakness against differential attack, slow performance speed, and unacceptable data expansion. In this paper, we introduce a new chaotic block cipher scheme for image cryptosystems that encrypts block of bits rather than block of pixels. It encrypts 256-bits of plainimage to 256-bits of cipherimage within eight 32-bit registers. The scheme employs the cryptographic primitive operations and a non-linear transformation function within encryption operation, and adopts round keys for encryption using a chaotic system. The new scheme is able to encrypt large size of images with superior performance speed than other schemes. The security analysis of the new scheme confirms a high security level and fairly uniform distribution.
Opto-digital spectrum encryption by using Baker mapping and gyrator transform
Chen, Hang; Zhao, Jiguang; Liu, Zhengjun; Du, Xiaoping
2015-03-01
A concept of spectrum information hidden technology is proposed in this paper. We present an optical encryption algorithm for hiding both the spatial and spectrum information by using the Baker mapping in gyrator transform domains. The Baker mapping is introduced for scrambling the every single band of the hyperspectral image before adding the random phase functions. Subsequently, three thin cylinder lenses are controlled by PC for implementing the gyrator transform. The amplitude and phase information in the output plane can be regarded as the encrypted information and main key. Some numerical simulations are made to test the validity and capability of the proposed encryption algorithm.
Exploration of Military Logistics Database Encryption and AES Algorithm%军事物流数据库加密与AES算法的探究
王凤忠; 吕亚飞; 邹饶邦彦
2016-01-01
In this paper, in light of the dire situation of database safety of the military logistics information system, we analyzed the database encryption technology and the encryption and decryption processes and the round key generation process of the AES algorithm, used Java to realize the programming and testing of the algorithm in My Eclipse and at the end, through a numerical example, demonstrated the validity of the algorithm.%针对目前军事物流信息系统中数据库安全面临的严峻形势，分析数据库加密技术方法和AES算法的加解密过程及轮密钥生成过程，采用Java语言在my eclipse中实现AES算法的编程及测试，通过实例验证了算法的有效性。
Optical Encryption with Jigsaw Transform using Matlab
Giraldo, Leidy Marcela
2012-01-01
This article will describe an optical encryption technical of images which it is proposed in an analogical and digital way. The development of the technical to a digital level, it is made to implementing algorithms (routines) in MATLAB. We will propose a functional diagram to the described analogical development from which designated the optical systems associated with each functional block. Level of security that the jigsaw algorithms provide applied on an image, which has been decomposed into its bit-planes, is significantly better if they are applied on an image that has not been previously decomposed.
A Novel Steganographic Scheme Based on Hash Function Coupled With AES Encryption
Rinu Tresa M J
2014-04-01
Full Text Available In the present scenario the use of images increased extremely in the cyber world so that we can easily transfer data with the help of these images in a secured way. Image steganography becomes important in this manner. Steganography and cryptography are the two techniques that are often confused with each other. The input and output of steganogra phy looks alike, but for cryptography the output will be in an encrypted form which always draws attraction to the attacker. This paper combines both steganography and cryptography so that attacker doesn’t know about the existence of message and the message itself is encrypted to ensure more security. The textual data entered by the user is encrypted using AES algorithm. After encryption, the encrypted data is stored in the colour image by using a hash based algorithm. Most of the steganographic algorithms available today is suitable for a specific image format and these algorithms suffers from poor quality of the embedded image. The proposed work does not corrupt the images quality in any form. The striking feature is that this algorithm is suitable for almost all image formats e.g.: jpeg/jpg, Bitmap, TIFF and GIF
Image Compression Algorithms Using Dct
Er. Abhishek Kaushik
2014-04-01
Full Text Available Image compression is the application of Data compression on digital images. The discrete cosine transform (DCT is a technique for converting a signal into elementary frequency components. It is widely used in image compression. Here we develop some simple functions to compute the DCT and to compress images. An image compression algorithm was comprehended using Matlab code, and modified to perform better when implemented in hardware description language. The IMAP block and IMAQ block of MATLAB was used to analyse and study the results of Image Compression using DCT and varying co-efficients for compression were developed to show the resulting image and error image from the original images. Image Compression is studied using 2-D discrete Cosine Transform. The original image is transformed in 8-by-8 blocks and then inverse transformed in 8-by-8 blocks to create the reconstructed image. The inverse DCT would be performed using the subset of DCT coefficients. The error image (the difference between the original and reconstructed image would be displayed. Error value for every image would be calculated over various values of DCT co-efficients as selected by the user and would be displayed in the end to detect the accuracy and compression in the resulting image and resulting performance parameter would be indicated in terms of MSE , i.e. Mean Square Error.
A novel chaotic encryption scheme based on pseudorandom bit padding
Sadra, Yaser; Fard, Zahra Arasteh
2012-01-01
Cryptography is always very important in data origin authentications, entity authentication, data integrity and confidentiality. In recent years, a variety of chaotic cryptographic schemes have been proposed. These schemes has typical structure which performed the permutation and the diffusion stages, alternatively. The random number generators are intransitive in cryptographic schemes and be used in the diffusion functions of the image encryption for diffused pixels of plain image. In this paper, we propose a chaotic encryption scheme based on pseudorandom bit padding that the bits be generated by a novel logistic pseudorandom image algorithm. To evaluate the security of the cipher image of this scheme, the key space analysis, the correlation of two adjacent pixels and differential attack were performed. This scheme tries to improve the problem of failure of encryption such as small key space and level of security.
Advanced Imaging Algorithms for Radiation Imaging Systems
Marleau, Peter [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
2015-10-01
The intent of the proposed work, in collaboration with University of Michigan, is to develop the algorithms that will bring the analysis from qualitative images to quantitative attributes of objects containing SNM. The first step to achieving this is to develop an indepth understanding of the intrinsic errors associated with the deconvolution and MLEM algorithms. A significant new effort will be undertaken to relate the image data to a posited three-dimensional model of geometric primitives that can be adjusted to get the best fit. In this way, parameters of the model such as sizes, shapes, and masses can be extracted for both radioactive and non-radioactive materials. This model-based algorithm will need the integrated response of a hypothesized configuration of material to be calculated many times. As such, both the MLEM and the model-based algorithm require significant increases in calculation speed in order to converge to solutions in practical amounts of time.
Zhang, Yushu; Xiao, Di; Wen, Wenying; Tian, Yuan
2013-12-01
In some special multimedia applications, only the regions with semantic information should be provided better protection whereas the other smooth regions can be free of encryption. However, most of the existing multimedia security schemes only consider bits and pixels rather than semantic information during their encryption. Motivated by this, we propose an edge-based lightweight image encryption scheme using chaos-based reversible hidden transform and multiple-order discrete fractional cosine transform. An image is first carried out by the edge detection based on advanced CNN structure with adaptive thresholds to assess data significance in the image. The detection output is a binary image, in which a “1” reflects the detected pixel whereas a “0” is opposite. Both the detected image and the original image are divided into non-overlapping pixel blocks in the same way, respectively. Whether each block is encrypted or not depends on the significance judged by the corresponding detected block. The significant block is performed by reversible hidden transform followed by multiple-order discrete fractional cosine transform parameters and orders of these two transforms are determined by a two dimensional cross chaotic map. Experiment results show the significant contour features of an image that have been largely hidden only by encrypting about half pixels in the average sense. The keys are extremely sensitive and the proposed scheme can resist noise attack to some extent.
基于MD5与Base64的混合加密算法%MD5-Base64 based hybrid encryption algorithm
罗江华
2012-01-01
介绍了一种基于MD5和Base64的混合加密算法,首先将明文MD5加密得到32位16进制密文,再将32位密文拆分成16个2位16进制数组,并转换成对应的二进制数,最后将16个二进制数组连接成一个128位的2进制数,采用Base64加密原理进行加密.该算法可以避免查询MD5散列值字典获取用户明文密码,更加有效地保证了用户的密码安全,最后给出了算法的PHP实现.%A MD5-Base64 baaed hybrid encryption algorithm was introduced, which encrypted plain text to 32-bit hexadecimal cipher text by MDS encryption, then split this 32-bit hexadecimal into 16 parts, and transformed them into binary Cor each part to join them together as a 128-bit binary, finally, encrypted the 128-bit binary array by using Base64 algorithm. This algorithm can avoid getting user's clear text password by querying MDS hash database, and protect user's password more effectively. This algorithm was described by PHP script language at the fourth section.
A New Measurement Method of Iimage Encryption
Yu, X Y [College of Measurement-Control Tech and Communications Engineering, Harbin University of Science and Technology, Harbin, 150080 (China); Zhang, J [College of Measurement-Control Tech and Communications Engineering, Harbin University of Science and Technology, Harbin, 150080 (China); Ren, H E [Information and Computer Engineering College, Northeast Forestry University, Harbin, 150000 (China); Li, S [College of Measurement-Control Tech and Communications Engineering, Harbin University of Science and Technology, Harbin, 150080 (China); Zhang, X D [College of Measurement-Control Tech and Communications Engineering, Harbin University of Science and Technology, Harbin, 150080 (China)
2006-10-15
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.
Listless zerotree image compression algorithm
Lian, Jing; Wang, Ke
2006-09-01
In this paper, an improved zerotree structure and a new coding procedure are adopted, which improve the reconstructed image qualities. Moreover, the lists in SPIHT are replaced by flag maps, and lifting scheme is adopted to realize wavelet transform, which lowers the memory requirements and speeds up the coding process. Experimental results show that the algorithm is more effective and efficient compared with SPIHT.
赵丽; 齐兴斌; 李雪梅; 田涛
2014-01-01
For the security issue of two-dimensional image encryption, an optical image fusion fractional Fouri-er transform and image replacement techniques of encryption scheme is proposed. Firstly, jigsaw transform algo-rithm is used to decompose the original image into several sub graphs, shifting subgraph randomly. Then, Arnold transform (ART) is used to scramble pixel of image. Finally, scrambling image by using fractional Fourier transform, and repeat the process of iteration. The jigsaw array index, Arnold frequency and fractional Fourier order parameters constitute a key space. Through the simulation in the optical implementation evaluation of the performance of algo-rithm, experimental results show that proposed scheme has better flexibility and robustness.%针对二维图像加密系统的安全性问题，本文提出一种融合分数傅里叶变换和图像置换技术的光学图像加密方案。首先，使用jigsaw变换算法将原始图像分解成若干子图，并随机平移子图；然后，利用Arnold变换对图像像素进行置乱；最后，采用分数傅里叶变换加密置乱图像，并迭代重复这些过程。将jigsaw排列指标、Arnold频率和分数傅里叶阶等参数组成一个密钥空间，通过仿真实验在光学实现方面评估算法性能。实验结果表明，本文提出的方案具有很好的灵活性和鲁棒性。
Image Compression using GSOM Algorithm
SHABBIR AHMAD
2015-10-01
Full Text Available
沈学举; 刘旭敏; 许芹祖; 林超
2014-01-01
为了减少加密系统所用模板数，简化隐藏图像对解密过程的影响，采用球面波照明研究了基于傅里叶变换全息的多图像加密隐藏方法，并进行了加密、加密图像隐藏和解密的理论分析和数值模拟，加密图像和原始图像间的相关系数趋于0，宿主图像和加密图像的叠加系数ρ＜0．3时，宿主图像和隐藏图像的相关系数趋于1，解密图像和原始图像间的相关系数趋于1。结果表明，该加密隐藏方法的加密、解密和隐藏效果良好。%To reduce the number of binary random phase mask used in an image encryption system and simplify the effect of hidden encryption images on decryption process , an optical multiple-image encryption and hiding scheme was put forward based on Fourier transform holography under spherical wave illumination .Theoretical analysis and numerical simulation of image encryption and hiding encryption image and image decryption were made .The results show that correlation coefficient between encryption image and original image approaches 0, correlation coefficient between host image and hiding encryption image approaches 1 when superposition coefficient ρbetween host image and hiding encryption image is less than 0.3, correlation coefficient between decryption image and original image approaches 1.The encryption method can obtain good encryption effect .
Image feature extraction in encrypted domain with privacy-preserving SIFT.
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.
Secure Search Algorithm for Conjunctive Keyword in Encrypted Data%加密数据中连接关键词的安全搜索算法
刘星毅
2009-01-01
该算法把生成"能力"的过程分为线下和线上2个部分,它对多个连接关键词的安全搜索时间比原有算法降低了80%左右,实例分析结果验证了其正确性和有效性.%Existing keyword search algorithms can only deal with single keyword and presenting high time complexity. Aiming at this problem, this paper proposes a secure search algorithm for encrypted data which searches several conjunctive keywords at the same time. This algorithm partitions the processes for generating "Capability" into two parts -- online part and offline part. Its run time of secure search is about eighty percents less than existing algorithms. Example analysis results show that this algorithm is reasonable and effective.
Improved decryption quality and security of a joint transform correlator-based encryption system
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.
Private predictive analysis on encrypted medical data.
Bos, Joppe W; Lauter, Kristin; Naehrig, Michael
2014-08-01
Increasingly, confidential medical records are being stored in data centers hosted by hospitals or large companies. As sophisticated algorithms for predictive analysis on medical data continue to be developed, it is likely that, in the future, more and more computation will be done on private patient data. While encryption provides a tool for assuring the privacy of medical information, it limits the functionality for operating on such data. Conventional encryption methods used today provide only very restricted possibilities or none at all to operate on encrypted data without decrypting it first. Homomorphic encryption provides a tool for handling such computations on encrypted data, without decrypting the data, and without even needing the decryption key. In this paper, we discuss possible application scenarios for homomorphic encryption in order to ensure privacy of sensitive medical data. We describe how to privately conduct predictive analysis tasks on encrypted data using homomorphic encryption. As a proof of concept, we present a working implementation of a prediction service running in the cloud (hosted on Microsoft's Windows Azure), which takes as input private encrypted health data, and returns the probability for suffering cardiovascular disease in encrypted form. Since the cloud service uses homomorphic encryption, it makes this prediction while handling only encrypted data, learning nothing about the submitted confidential medical data.
Spaceborne SAR Imaging Algorithm for Coherence Optimized.
Zhiwei Qiu
Full Text Available This paper proposes SAR imaging algorithm with largest coherence based on the existing SAR imaging algorithm. The basic idea of SAR imaging algorithm in imaging processing is that output signal can have maximum signal-to-noise ratio (SNR by using the optimal imaging parameters. Traditional imaging algorithm can acquire the best focusing effect, but would bring the decoherence phenomenon in subsequent interference process. Algorithm proposed in this paper is that SAR echo adopts consistent imaging parameters in focusing processing. Although the SNR of the output signal is reduced slightly, their coherence is ensured greatly, and finally the interferogram with high quality is obtained. In this paper, two scenes of Envisat ASAR data in Zhangbei are employed to conduct experiment for this algorithm. Compared with the interferogram from the traditional algorithm, the results show that this algorithm is more suitable for SAR interferometry (InSAR research and application.
许柯; 刘绪崇; 符振艾; 徐宇宏
2015-01-01
According to traditional RSA algorithm has low speed of computing and bad encryption result for encrypting the network information, this article puts forward the RSA encryption algorithm of network information with relevant improved SMM algorithm. The first step is to optimize the modulus and multiplication time of SMM algorithm, the second step is to use the improved SMM algorithm to optimize the RSA algorithm, aiming at the modified algorithm of binary hamming weight in the index, the purpose is to reduce the iteration number, eventually improve the encryption of original algorithm. Seen from the algorithm simulation results, compared with SMM algorithm, the proposed RSA network information encryption algorithm based on improved SMM algorithm and traditional RSA encryption algorithm has faster process of encryption and decryption, and has stronger encryption effect.%针对传统RSA算法在对网络信息进行加密的时候还存在运算速度不快、加密效果不好的问题，本文提出有关改进SMM算法的RSA网络信息加密算法，第一步是针对SMM算法的求模运算量以及乘法时间进行优化操作，第二步是使用改进的SMM算法对RSA算法进行优化，针对其算法的二进制指数中的汉明重量进行改良，目的是为了减少迭代数，最终提升原来算法的加密功能。通过算法仿真实验结果可以看出，本文提出的基于改进SMM算法的RSA网络信息加密算法以及传统RSA加密算法，再与SMM算法进行比较，加密以及解密过程的速度更快，并且加密效果更强。
Image Compression Using Harmony Search Algorithm
Ryan Rey M. Daga
2012-09-01
Full Text Available Image compression techniques are important and useful in data storage and image transmission through the Internet. These techniques eliminate redundant information in an image which minimizes the physical space requirement of the image. Numerous types of image compression algorithms have been developed but the resulting image is still less than the optimal. The Harmony search algorithm (HSA, a meta-heuristic optimization algorithm inspired by the music improvisation process of musicians, was applied as the underlying algorithm for image compression. Experiment results show that it is feasible to use the harmony search algorithm as an algorithm for image compression. The HSA-based image compression technique was able to compress colored and grayscale images with minimal visual information loss.
FPGA Implementation of Secure Force (64-Bit Low Complexity Encryption Algorithm
Shujaat Khan
2015-11-01
Full Text Available Field-Programmable Gate Arrays (FPGAs have turned out to be a well-liked target for implementing cryptographic block ciphers, a well-designed FPGA solution can combine some of the algorithmic flexibility and cost efficiency of an equivalent software implementation with throughputs that are comparable to custom ASIC designs. The recently proposed Secure Force (SF shows good results in terms of resource utilization compared to older ciphers. SF appears as a promising choice for power and resource constrained secure systems and is well suited to an FPGA implementation. In this paper we explore the design decisions that lead to area/delay tradeoffs in a full loop-unroll implementation of SF-64 on FPGA. This work provides hardware characteristics of SF along with implementation results that are optimal in terms of throughput, latency, power utilization and area efficiency.
Medical Image Protection using steganography by crypto-image as cover Image
Vinay Pandey
2012-09-01
Full Text Available This paper presents securing the transmission of medical images. The presented algorithms will be applied to images. This work presents a new method that combines image cryptography, data hiding and Steganography technique for denoised and safe image transmission purpose. In This method we encrypt the original image with two shares mechanism encryption algorithm then embed the encrypted image with patient information by using lossless data embedding technique with data hiding method after that for more security. We apply steganography by encrypted image of any other medical image as cover image and embedded images as secrete image with the private key. In receiver side when the message is arrived then we apply the inverse methods in reverse order to get the original image and patient information and to remove noise we extract the image before the decryption of message. We have applied and showed the results of our method to medical images.
SOFTWARE IMPLEMENTATION OF AN ECC ENCRYPTION ALGORITHM OVER PRIME FIELDS%素数域上ECC加密算法的软件实现
刘磊
2012-01-01
椭圆曲线密码是目前公认的每比特安全性最高的密码体制,它具有安全性高、速度快、密钥短、实现时所需占用资源少等优点,非常适合应用于银行结算、电子商务和通信等领域,因此研究椭圆曲线密码的实现有重要意义.首先讨论椭圆曲线密码基本理论,然后介绍安全椭圆曲线选取方法以及经典的ECC加密算法,最后在Core(TM)2 Duo CPU E7500 2.93GHz实验平台上用标准C语言对该算法进行实现,验证该加密算法的可行性.%The elliptic curve cryptography (ECC) is generally recognised at present as the most secure encryption system, which provides highest level of security strength-per-bit and has many advantages such as higher safety property, faster speed, shorter key lengths and fewer computational resources for implementation, and is very suitable for the sectors of bank settlement, e-commerce and communication. Therefore it is of significance to study the software implementation of ECC encryption algorithm. In this paper, we first introduce the basic theory of elliptic curve cryptography, and then describe the way to select a secure elliptic curve and the classic ECC encryption algorithm. Finally, we implement this algorithm in C and the assembler on a Core(TM)2 Duo CPU E75OO 2.93GHz workstation, and testify the feasibility of it.
潘期辉
2015-01-01
Random code information encryption is the basis of the security of information security. Traditional random code information encryption algorithm using high order linear micro decomposition optimization of hybrid encryption algorithm, the key expansion process, link layer encrypting data nonlinear mutation, through all the affine transform any wheel key can crack the secret keys, encryption performance bad. A double thread complementary information encryption algorithm based on the amplitude modulation of random codes is proposed. Analysis of the random coding sequence encryption of informa-tion and communication system principle and key design, generate random number source of a source key and encryption sequence the bitwise XOR operation of double thread information complementary encoding and decoding, using random code amplitude modulation production information and decryption key, the encryption algorithm to achieve improved. Simu-lation results show that using this algorithm to encrypt information and the other information systems of password recogni-tion rate is effectively reduced, is difficult to attack detection and recognition system, improve the safety of information.%随机码信息加密是保障信息通信安全的基础,传统的随机码信息加密算法采用高阶线性微分解优化的混合加密算法,密钥扩展过程中,链路层加密数据出现非线性突变,采用任何一轮子密钥即可破解全部密钥,加密性能不好.提出一种基于随机码幅度调制的双线程互补信息加密算法.分析了加密信息通信系统的随机编码序列发生原理,进行密钥设计,生成的随机数对信源发出信源密钥,加密序列按位异或运算进行双线程信息互补编码和解码,采用随机码幅度调制生产信息加密密钥,实现加密算法改进,仿真结果表明,采用该算法进行信息加密,有效降低了对方信息系统对密码的识别率,难以被攻击系统检测识别,提高信息安全性.
STEGANOGRAPHY FOR TWO AND THREE LSBs USING EXTENDED SUBSTITUTION ALGORITHM
R.S. Gutte
2013-03-01
Full Text Available The Security of data on internet has become a prior thing. Though any message is encrypted using a stronger cryptography algorithm, it cannot avoid the suspicion of intruder. This paper proposes an approach in such way that, data is encrypted using Extended Substitution Algorithm and then this cipher text is concealed at two or three LSB positions of the carrier image. This algorithm covers almost all type of symbols and alphabets. The encrypted text is concealed variably into the LSBs. Therefore, it is a stronger approach. The visible characteristics of the carrier image before and after concealment remained almost the same. The algorithm has been implemented using Matlab.
基于FTP的图像混沌加密传输技术的实现%Implementation of transmitting chaotic-encrypted image based on FTP
刘新杰; 李黎明
2014-01-01
In order to accelerate the rate of chaotic-encrypted image transmission system and extend its field of application , this paper proposes a new method of transmitting chaotic-encrypted image: applying VSFTPD software to Mini 2440 ARM platform to setup a FTP server , and using FTP to convey the encrypted image files . The experiment result shows that this system can trans-fer chaotic-encrypted images rapidly and reliably .%为了提高混沌图像加密传输系统的传输速度并扩大应用范围，提出了一种实现混沌图像加密传输的新方法：利用 VSFTPD 软件在 Mini 2440 ARM 平台上构建 FTP 服务器，通过 FTP 实现混沌加密图像数据的传输。实验结果表明，该系统能够实现混沌加密图像的可靠快速传输。
On a New Video Encryption Algorithm Based on CNN Hyperchaos%基于 CNN 超混沌的视频加密新算法
朱艳平
2016-01-01
针对视频数据实时性高，数据量大等特点，提出了一种基于细胞神经网络的视频加密新算法。该算法以五维CNN 作为密钥源，根据明文视频帧的尺寸和明文视频帧本身来选择加密密钥，依据扩散思想，对视频进行加密处理。该算法加/解密速度快，可对任何格式的视频数据实现保密通信，具备通用性，且密钥敏感性和明文敏感性强，密钥空间大，可有效抵抗穷举攻击、统计分析攻击、已知明文攻击、选择明文攻击和密文攻击，安全性更高，具有一定的实用价值。%Aiming at video data high real-time performance,the characteristics of large amount of data, proposed a new video encryption algorithm based on cellular neural network.In the algorithm,five dimen-sional CNN hyperchaotic system have been used as key source,according to the plaintext video frame size and the plaintext video frame itself,selected the encryption key,based on diffusion theory,encrypted vid-eo.The encryption and decryption speed of the algorithm is fast,any format video data can achieve secure communications,has universality;the key sensitivity and plaintext sensitivity are strong,the key space is large.Can effectively resist brute attack,statistical attack,known plaintext attack,chosen plaintext at-tack and cipher text attack,has higher security and a certain practical value.
冯祥斌; 陈永红
2014-01-01
结合 P-Fibonacci 加密算法和模糊归类，提出一种自适应水印新算法。利用 P-Fibonacci 加密具有良好的均匀性及安全性，将水印图像的像素位置打乱，消除了二维数字水印图像的像素空间相关性，使嵌入水印后的块效应降低。对原始载体图像进行分块，结合人类视觉系统的纹理和照度掩蔽特性，得到纹理模糊函数和各图像子块的归类结果，并自适应地确定水印的嵌入强度。对载体图像的各子块进行离散小波变换（DWT），将经 P-Fibonacci 加密算法加密后的水印信息重复嵌入各子块 DWT 域的低频部分。实验结果表明：该算法抗JPEG 压缩、高斯噪声、滤波等常见的信号攻击和几何攻击具有很好的鲁棒性。%A new adaptive watermarking algorithm based on P-Fibonacci encryption and fuzzy classified is proposed.The P-Fibonacci encryption has a good uniformity and safety,disrupting the watermark image′s pixel position by P-Fibonacci encryption algorithm,which can eliminate the spatial correlation of the two-dimensional digital watermark image pixels, and ultimately,reducing the blockiness when embedding watermark information.Simultaneously,blocked the original carrier image,and according to the texture and illumination masking characteristics of the human visual system,obtained a fuzzy function which based on the texture characteristics of the original image,establishing the texture fuzzy function and the classification results of each sub-block,according to the results,determined the embedding strength adaptively. Then discrete wavelet transform (DWT)is performed on the sub-images,and the encrypted watermarks were embedded in the low frequency of the DWT domain repeatedly.The experimental results show that the presented algorithm has a good robustness against common signal processing attacks such as JPEG compression,Gaussian noise,filtering and geo-metric attack such as cropping.
Image Classification through integrated K- Means Algorithm
Balasubramanian Subbiah
2012-03-01
Full Text Available Image Classification has a significant role in the field of medical diagnosis as well as mining analysis and is even used for cancer diagnosis in the recent years. Clustering analysis is a valuable and useful tool for image classification and object diagnosis. A variety of clustering algorithms are available and still this is a topic of interest in the image processing field. However, these clustering algorithms are confronted with difficulties in meeting the optimum quality requirements, automation and robustness requirements. In this paper, we propose two clustering algorithm combinations with integration of K-Means algorithm that can tackle some of these problems. Comparison study is made between these two novel combination algorithms. The experimental results demonstrate that the proposed algorithms are very effective in producing desired clusters of the given data sets as well as diagnosis. These algorithms are very much useful for image classification as well as extraction of objects.
CHAOS-BASED ADVANCED ENCRYPTION STANDARD
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
Objective measurement for image defogging algorithms
郭璠; 唐琎; 蔡自兴
2014-01-01
Since there is lack of methodology to assess the performance of defogging algorithm and the existing assessment methods have some limitations, three new methods for assessing the defogging algorithm were proposed. One was using synthetic foggy image simulated by image degradation model to assess the defogging algorithm in full-reference way. In this method, the absolute difference was computed between the synthetic image with and without fog. The other two were computing the fog density of gray level image or constructing assessment system of color image from human visual perception to assess the defogging algorithm in no-reference way. For these methods, an assessment function was defined to evaluate algorithm performance from the function value. Using the defogging algorithm comparison, the experimental results demonstrate the effectiveness and reliability of the proposed methods.
Encryption Algorithm Based on Multi-dimensional Code QR%基于QR二维码的多重加密算法研究
廖镇勋; 王珏
2015-01-01
随着二维码技术在社会上的不断推广,有关于二维码的多重加密算法的研究也越来越受到大众的关注.相对于普通二维码而言,QR二维码即快速响应二维码更受到大家的喜爱.QR二维码具备时代性,满足现代社会发展下的人们日常生活需求.QR二维码的算法设计运用到了许多层面的知识,设计从简便入手,方便大众使用.该文从QR二维码的特点着手,在此基础上研究关于二维码的多重加密算法,通过针对不同阶段QR二维码的差异,采取不同的措施和手段去提高QR二维码的加密程度.这种算法不仅减少了由于技术不完善等原因造成的信息泄露,也从根本上完善了人为原因所造成的信息泄露的缺陷.%With the continuous promotion of two-dimensional code technology in society, the study has multiple encryption algo-rithms on two-dimensional code more and more attention by the general public. Compared to ordinary two-dimensional code is concerned, QR two-dimensional code that is more rapid response to a two-dimensional code loved by everyone. The QR code with the times to meet the needs of daily life in modern society Development. QR algorithm applied to the two-dimensional code knowledge at many levels, from simple start design and convenient public. In this paper, the characteristics of the QR code to proceed to study two-dimensional code on multiple encryption algorithms on this basis, the difference for the different stages through the QR code and take different measures and means to increase the degree of the QR code encryption . This algorithm not only reduces imperfect information leaks due to technical reasons, but also to improve the information leakage caused by man-made causes of defects fundamentally.
Optical encryption with cascaded fractional wavelet transforms
BAO Liang-hua; CHEN Lin-fei; ZHAO Dao-mu
2006-01-01
On the basis of fractional wavelet transform, we propose a new method called cascaded fractional wavelet transform to encrypt images. It has the virtues of fractional Fourier transform and wavelet transform. Fractional orders, standard focal lengths and scaling factors are its keys. Multistage fractional Fourier transforms can add the keys easily and strengthen information security. This method can also realize partial encryption just as wavelet transform and fractional wavelet transform. Optical realization of encryption and decryption is proposed. Computer simulations confirmed its possibility.
Comparative Study of Image Denoising Algorithms in Digital Image Processing
Aarti
2014-05-01
Full Text Available This paper proposes a basic scheme for understanding the fundamentals of digital image processing and the image denising algorithm. There are three basic operation categorized on during image processing i.e. image rectification and restoration, enhancement and information extraction. Image denoising is the basic problem in digital image processing. The main task is to make the image free from Noise. Salt & pepper (Impulse noise and the additive white Gaussian noise and blurredness are the types of noise that occur during transmission and capturing. For denoising the image there are some algorithms which denoise the image.
Comparative Study of Image Denoising Algorithms in Digital Image Processing
Aarti Kumari
2015-11-01
Full Text Available This paper proposes a basic scheme for understanding the fundamentals of digital image processing and the image denising algorithm. There are three basic operation categorized on during image processing i.e. image rectification and restoration, enhancement and information extraction. Image denoising is the basic problem in digital image processing. The main task is to make the image free from Noise. Salt & pepper (Impulse noise and the additive white Gaussian noise and blurredness are the types of noise that occur during transmission and capturing. For denoising the image there are some algorithms which denoise the image.
Volumetric Light-field Encryption at the Microscopic Scale
Li, Haoyu; Guo, Changliang; Muniraj, Inbarasan; Schroeder, Bryce C.; Sheridan, John T.; Jia, Shu
2017-01-01
We report a light-field based method that allows the optical encryption of three-dimensional (3D) volumetric information at the microscopic scale in a single 2D light-field image. The system consists of a microlens array and an array of random phase/amplitude masks. The method utilizes a wave optics model to account for the dominant diffraction effect at this new scale, and the system point-spread function (PSF) serves as the key for encryption and decryption. We successfully developed and demonstrated a deconvolution algorithm to retrieve both spatially multiplexed discrete data and continuous volumetric data from 2D light-field images. Showing that the method is practical for data transmission and storage, we obtained a faithful reconstruction of the 3D volumetric information from a digital copy of the encrypted light-field image. The method represents a new level of optical encryption, paving the way for broad industrial and biomedical applications in processing and securing 3D data at the microscopic scale. PMID:28059149
Volumetric Light-field Encryption at the Microscopic Scale
Li, Haoyu; Muniraj, Inbarasan; Schroeder, Bryce C; Sheridan, John T; Jia, Shu
2016-01-01
We report a light-field based method that allows the optical encryption of three-dimensional (3D) volumetric information at the microscopic scale in a single 2D light-field image. The system consists of a microlens array and an array of random phase/amplitude masks. The method utilizes a wave optics model to account for the dominant diffraction effect at this new scale, and the system point-spread function (PSF) serves as the key for encryption and decryption. We successfully developed and demonstrated a deconvolution algorithm to retrieve spatially multiplexed discrete and continuous volumetric data from 2D light-field images. Showing that the method is practical for data transmission and storage, we obtained a faithful reconstruction of the 3D volumetric information from a digital copy of the encrypted light-field image. The method represents a new level of optical encryption, paving the way for broad industrial and biomedical applications in processing and securing 3D data at the microscopic scale.
Volumetric Light-field Encryption at the Microscopic Scale
Li, Haoyu; Guo, Changliang; Muniraj, Inbarasan; Schroeder, Bryce C.; Sheridan, John T.; Jia, Shu
2017-01-01
We report a light-field based method that allows the optical encryption of three-dimensional (3D) volumetric information at the microscopic scale in a single 2D light-field image. The system consists of a microlens array and an array of random phase/amplitude masks. The method utilizes a wave optics model to account for the dominant diffraction effect at this new scale, and the system point-spread function (PSF) serves as the key for encryption and decryption. We successfully developed and demonstrated a deconvolution algorithm to retrieve both spatially multiplexed discrete data and continuous volumetric data from 2D light-field images. Showing that the method is practical for data transmission and storage, we obtained a faithful reconstruction of the 3D volumetric information from a digital copy of the encrypted light-field image. The method represents a new level of optical encryption, paving the way for broad industrial and biomedical applications in processing and securing 3D data at the microscopic scale.
High Lightweight Encryption Standard (HLES as an Improvement of 512-Bit AES for Secure Multimedia
GUESMIA Seyf Eddine
2016-01-01
Full Text Available In today’s scenario, people share information to another people frequently using network. Due to this, more amount of information are so much private but some are less private. Therefore, the attackers or the hackers take the advantage and start attempting to steal the information since 2001. the symmetric encryption algorithm called 512-bit AES provides high level of security, but it's almost be impossible to be used in multimedia transmissions and mobile systems because of the need for more design area that effect in the use of large memory space in each round and the big encryption time that it takes. This paper presents an improvement of 512-bit AES algorithm with efficient utilization of resources such as processor and memory space. The proposed approach resists the linear and differential encrypt analysis and provides high security level using a 512-bit size of key block and data block and ameliorates the performance by minimizing the use of memory space and time encryption to be able to work in specific characteristics of resource-limited systems. The experimental results on several data (text, image, sound, video show that the used memory space is reduced to quarter, and the encryption time is reduced almost to the half. Therefore, the adopted method is very effective for encryption of multimedia data.
柏森; 郭雨; 赵波; 代勤芳
2016-01-01
在视频点播等应用中，为了刺激消费者购买高质量的视频，需要对视频进行特别的感知加密，使视频加密后仍然部分可见。该文提出一种Context-based Adaptive Binary Arithmetic Coding (CABAC)的视觉质量可控的快速感知加密算法。利用2D超混沌系统生成的流密码对重要的语法元素和敏感的编码元素异或加密。加密内容包括运动矢量差的符号位、非零系数符号位和语法元素significant_coeff_flag。分析及实验结果表明，提出的感知加密算法对码率无影响，编码时间仅增加7‰左右，视频质量随着质量因子的改变而变化，满足视频感知加密的应用需求。%In Video on Demand (VoD) applications it is desired that the encrypted multimedia data are still partially perceptible after encryption in order to stimulate the purchase of the high-quality versions of the multimedia products. This perceptual encryption requires specific algorithms for encrypting the video data. In this paper, a Context-based Adaptive Binary Arithmetic Coding (CABAC) video perceptual encryption scheme is designed. The video quality of this encryption scheme is controllable. The important syntax elements and sensitive coded elements are chosen to encrypt using mathematical XOR operations with stream ciphers generated by 2D hyper chaos system. The encryption scheme is composed of encrypting Motion Vector Differences (MVD) sign, non-zero coefficients sign and significant_coeff_flag. Theoretical analysis and experimental results show that the proposed scheme has no impact on bit rate. With the 7‰ encoding time increasing, the video quality can be controlled by the change of the quality factor, which meets the requirement of the video perceptual encryption.
A RANDOMIZED SELECTIVE ENCRYPTION USING HASHING TECHNIQUE FOR SECURING VIDEO STREAMS
Lizyflorance. C
2012-11-01
Full Text Available Digital video transmissions are widely used in network nowadays. Hence, securing its contents and keeping privacy is vital. Several encryption algorithms have been proposed earlier to achieve securevideo transmission. But altogether attaining efficiency, security and flexibility is a major challenge. To transmit a digital video, encryption is necessary to protect its contents from attacks. As the size of the videos are usually large their contents has to be compressed before transmission. Encryption is applied on the video content after compression. One of the encryption technique selective encryption is used for encrypting video. It encrypts only a subset of data. The selective encryption algorithm reduces the amount of the data to be encrypted and achieves a required level of security. In this paper we study the existing selective encryption algorithm and its classifications. The challenges in the selective encryptionalgorithms and some future directions are presented.
An efficient algorithm for color image segmentation
Shikha Yadav
2016-09-01
Full Text Available In field of image processing, image segmentation plays an important role that focus on splitting the whole image into segments. Representation of an image so that it can be more easily analysed and involves more information is an important segmentation goal. The process of partitioning an image can be usually realized by Region based, Boundary based or edge based method. In this work a hybrid approach is followed that combines improved bee colony optimization and Tabu search for color image segmentation. The results produced from this hybrid approach are compared with non-sorted particle swarm optimization, non-sorted genetic algorithm and improved bee colony optimization. Results show that the Hybrid algorithm has better or somewhat similar performance as compared to other algorithms that are based on population. The algorithm is successfully implemented on MATLAB.
吴文玲; 贺也平; 冯登国; 卿斯汉
2001-01-01
简要介绍了欧洲NESSIE(new European schemes for signatures, integrity, and encrypt ion)大计划最近公布的17个分组密码算法的基本设计思想、最新分析结果及其有效性%In this paper, the basic design ideas, recent analysis results and validity of the 17 NESSIE (new european schemes for signat ures, integrity, and encryption) candidate algorithms are introduced.
P. T. Anitha
2012-01-01
Full Text Available Problem statement: The major growth of information technology is based on the security measures implemented. Steganography is a method which is used to give high level security. Approach: Today, email management and email authenticity must be unquestionable with strong chains of custody, constant availability and tamper-proof security. A secure communication can be achieved through neural based steganography. Email is insecure. Results: This research developed an application which can check the Email content of corporate mails by S-DES algorithm along with the neural networks back propagation approach. A new filtering algorithm is also developed which can used to extract only the JPG images from the corporate emails. Experimental research shows that this algorithm is more accurate and reliable than the conventional methods. Conclusion: We anticipate that this study can also give a clear picture of the current trends in Steganography and the experimental results indicate this method is valid in steganalysis. This method can be used for internet/network security.
Image Encryption Communication System Based on Logistic Map%基于Logistic混沌映射的图像加密通信系统研究
刘昕浩; 郭腾; 谢德辉; 徐婷; 李春来
2015-01-01
基于二维图像离散余弦变换(DCT)和Logistic混沌映射设计一种图像加密通信系统.首先基于DCT将图像变换成频域系数,利用Logistic映射产生的随机序列对变换得到的频域系数进行排序,对改变后的DCT系数分布结构做离散余弦反变换,得到置乱图像;.然后利用Logistic映射结构简单、复杂度高等特性,在像素替换过程中利用辅助密钥修正系统初始值,并按图像像素空间位置奇偶序号依次构造加密密钥,同时将像素点灰度值加密处理,最终实现图像信息的加密通信.%An image encryption communication system based on Discrete Cosine Transform (DCT) and Logistic map is proposed. Firstly, using the DCT and random sequences from Logistic map, a shuffled image is obtained. Then, the security key is constructed by modifying the initial value of Logistic map. Finally, we realized the image encryption communication system by dealing with the gray values of the encrypted image.
唐高阳; 孙世坤
2015-01-01
The popularity of computer and the Importance to IPR protection have made great progresses in the Software encryption technology. That the AES algorithm is replacing the DES algorithm are prevalent. This paper first introduces a new method for encrypting text and decrypting text by the AES Algorithm, and designs an Example about the AES Algorithm basing on the platform of the Visual C++2010.%随着计算机的普及以及重视知识产权保护，使得软件加密技术蓬勃兴起，AES算法正取代DES算法成为使用广泛的新标准。介绍了如何运用AES算法对文档进行加密和解密，并给出了一个基于Visual C++2010开发平台和AES算法的实例。
Yang, Xiuping, E-mail: yangxiuping-1990@163.com; Min, Lequan, E-mail: minlequan@sina.com; Wang, Xue, E-mail: wangxue-20130818@163.com [Schools of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083 (China)
2015-05-15
This paper sets up a chaos criterion theorem on a kind of cubic polynomial discrete maps. Using this theorem, Zhou-Song's chaos criterion theorem on quadratic polynomial discrete maps and generalized synchronization (GS) theorem construct an eight-dimensional chaotic GS system. Numerical simulations have been carried out to verify the effectiveness of theoretical results. The chaotic GS system is used to design a chaos-based pseudorandom number generator (CPRNG). Using FIPS 140-2 test suit/Generalized FIPS 140-2, test suit tests the randomness of two 1000 key streams consisting of 20 000 bits generated by the CPRNG, respectively. The results show that there are 99.9%/98.5% key streams to have passed the FIPS 140-2 test suit/Generalized FIPS 140-2 test. Numerical simulations show that the different keystreams have an average 50.001% same codes. The key space of the CPRNG is larger than 2{sup 1345}. As an application of the CPRNG, this study gives an image encryption example. Experimental results show that the linear coefficients between the plaintext and the ciphertext and the decrypted ciphertexts via the 100 key streams with perturbed keys are less than 0.00428. The result suggests that the decrypted texts via the keystreams generated via perturbed keys of the CPRNG are almost completely independent on the original image text, and brute attacks are needed to break the cryptographic system.
Research and realization of SM2 elliptic curve public key encryption algorithm%SM2椭圆曲线公钥加密算法的研究与实现
李玉生
2016-01-01
随着互联网的发展，越来越多的信息交换通过网络进行，在这些信息中包含着不能为人所知的私密信息，例如，信用卡账号、银行账号、病历、电子邮件等。由于私密信息泄露产生不良后果的事件时有发生，这些都牵扯到对数据信息的加密问题。针对这一问题，文章提出运用SM2加密算法实现数据信息的加密，保证网络通信的安全性。事实表明，SM2公钥加密算法能够更加安全地加密数据信息，且加密的数据很难破译。%With the development of the Internet, more and more information is exchanged through the network, among those information, there are some private information that can not be known by others, for example, credit card accounts, bank accounts, medical record, e-mail, etc. Bad consequences caused by private information leakage occurred frequently, which is involved in the encryption of data information. In view of this problem, this paper proposes the use of SM2 encryption algorithm to achieve data encryption and ensure the security of network communication. Facts show that the SM2 public key encryption algorithm can encrypt data more safely, and the encryption data is dififcult to decipher.
Security in Fog Computing through Encryption
Akhilesh Vishwanath
2016-05-01
Full Text Available Cloud computing is considered as one of the most exciting technology because of its flexibility and scalability. The main problem that occurs in cloud is security. To overcome the problems or issues of security, a new technique called fog-computing is evolved. As there are security issues in fog even after getting the encrypted data from cloud, we implemented the process of encryption using AES algorithm to check how it works for the fog. So far, to our analysis AES algorithm is the most secured process of encryption for security. Three datasets of different types are considered and applied the analysed encryption technique over those datasets. On validation, entire data over datasets is being accurately encrypted and decrypted back as well. We took android mobile as an edge device and deployed the encryption over datasets into it. Further, performance of encryption is evaluated over selected datasets for accuracy if the entire data is correctly encrypted and decrypted along with the time, User load, Response time, Memory Utilization over file size. Further best and worst cases among the datasets are analysed thereby evaluating the suitability of AES in fog.
Veugen, P.J.M.
2010-01-01
When processing signals in the encrypted domain, homomorphic encryption can be used to enable linear operations on encrypted data. Integer division of encrypted data however requires an additional protocol with the server and will be relatively expensive. We present new solutions for dividing encryp
AN EFFICIENT BTC IMAGE COMPRESSION ALGORITHM
无
2000-01-01
Block truncation coding (BTC) is a simple and fast image compression technique suitable for realtime image transmission, and it has high channel error resisting capability and good reconstructed image quality. The main shortcoming of the original BTC algorithm is the high bit rate (normally 2 bits/pixel). In order to reduce the bit rate, an efficient BTC image compression algorithm was presented in this paper. In the proposed algorithm, a simple look-up-table method is presented for coding the higher mean and the lower mean of a block without any extra distortion, and a prediction technique is introduced to reduce the number of bits used to code the bit plane with some extra distortion. The test results prove the effectiveness of the proposed algorithm.
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.
User-friendly imaging algorithms for interferometry
Young, John; Thiébaut, Éric; Duvert, Gilles; Vannier, Martin; Garcia, Paulo; Mella, Guillaume
2016-08-01
OPTICON currently supports a Joint Research Activity (JRA) dedicated to providing easy to use image reconstruction algorithms for optical/IR interferometric data. This JRA aims to provide state-of-the-art image reconstruction methods with a common interface and comprehensive documentation to the community. These tools will provide the capability to compare the results of using different settings and algorithms in a consistent and unified way. The JRA is also providing tutorials and sample datasets to introduce the principles of image reconstruction and illustrate how to use the software products. We describe the design of the imaging tools, in particular the interface between the graphical user interface and the image reconstruction algorithms, and summarise the current status of their implementation.
Image Series Segmentation and Improved MC Algorithm
WAN Wei-bing; SHI Peng-fei
2008-01-01
A semiautomatic segmentation method based on active contour is proposed for computed tomog-raphy (CT) image series. First, to get initial contour, one image slice was segmented exactly by C-V method based on Mumford-Shah model. Next, the computer will segment the nearby slice automatically using the snake model one by one. During segmenting of image slices, former slice boundary, as next slice initial con-tour, may cross over next slice real boundary and never return to right position. To avoid contour skipping over, the distance variance between two slices is evaluated by an threshold, which decides whether to initiate again. Moreover, a new improved marching cubes (MC) algorithm based on 2D images series segmentation boundary is given for 3D image reconstruction. Compared with the standard method, the proposed algorithm reduces detecting time and needs less storing memory. The effectiveness and capabilities of the algorithm were illustrated by experimental results.
Image compression algorithm using wavelet transform
Cadena, Luis; Cadena, Franklin; Simonov, Konstantin; Zotin, Alexander; Okhotnikov, Grigory
2016-09-01
Within the multi-resolution analysis, the study of the image compression algorithm using the Haar wavelet has been performed. We have studied the dependence of the image quality on the compression ratio. Also, the variation of the compression level of the studied image has been obtained. It is shown that the compression ratio in the range of 8-10 is optimal for environmental monitoring. Under these conditions the compression level is in the range of 1.7 - 4.2, depending on the type of images. It is shown that the algorithm used is more convenient and has more advantages than Winrar. The Haar wavelet algorithm has improved the method of signal and image processing.
Least significant qubit algorithm for quantum images
Sang, Jianzhi; Wang, Shen; Li, Qiong
2016-11-01
To study the feasibility of the classical image least significant bit (LSB) information hiding algorithm on quantum computer, a least significant qubit (LSQb) information hiding algorithm of quantum image is proposed. In this paper, we focus on a novel quantum representation for color digital images (NCQI). Firstly, by designing the three qubits comparator and unitary operators, the reasonability and feasibility of LSQb based on NCQI are presented. Then, the concrete LSQb information hiding algorithm is proposed, which can realize the aim of embedding the secret qubits into the least significant qubits of RGB channels of quantum cover image. Quantum circuit of the LSQb information hiding algorithm is also illustrated. Furthermore, the secrets extracting algorithm and circuit are illustrated through utilizing control-swap gates. The two merits of our algorithm are: (1) it is absolutely blind and (2) when extracting secret binary qubits, it does not need any quantum measurement operation or any other help from classical computer. Finally, simulation and comparative analysis show the performance of our algorithm.
Least significant qubit algorithm for quantum images
Sang, Jianzhi; Wang, Shen; Li, Qiong
2016-08-01
To study the feasibility of the classical image least significant bit (LSB) information hiding algorithm on quantum computer, a least significant qubit (LSQb) information hiding algorithm of quantum image is proposed. In this paper, we focus on a novel quantum representation for color digital images (NCQI). Firstly, by designing the three qubits comparator and unitary operators, the reasonability and feasibility of LSQb based on NCQI are presented. Then, the concrete LSQb information hiding algorithm is proposed, which can realize the aim of embedding the secret qubits into the least significant qubits of RGB channels of quantum cover image. Quantum circuit of the LSQb information hiding algorithm is also illustrated. Furthermore, the secrets extracting algorithm and circuit are illustrated through utilizing control-swap gates. The two merits of our algorithm are: (1) it is absolutely blind and (2) when extracting secret binary qubits, it does not need any quantum measurement operation or any other help from classical computer. Finally, simulation and comparative analysis show the performance of our algorithm.
基于MD5加密的Tornado码复制算法改进%An improved algorithm based on MD5 encryption Tornado code
骆正平; 陈中育; 林郁峰; 吴星同
2015-01-01
Tornado code based replication algorithm had the advantages of faster encoding and decoding, and could also recover the original data when some data were missing, but when the algorithm was applied to a dis-tributed storage system, the presence of data would be susceptible to theft, tampering risk. For this reason, several optimization strategies were proposed to improve the replication algorithm based on Tornado code:1 ) an encryption mechanism into replication algorithm was introduced in case of even some data were stolen there would be no worry about information leak. 2)the raw data using the MD5 algorithm to generate digital finger-prints produced a digital fingerprint when retrieving data from a distributed storage system with local digital fin-gerprint comparison, it would be easy to determine whether the data had been tampered with.%基于Tornado码的复制算法具有编解码速度比较快、部分数据丢失时亦能被恢复的优点，但将该算法应用于分布式存储系统时，存在数据易被窃取、篡改的风险。为此，对基于Tornado码的复制算法提出了改进：1)引入加密机制，使数据即使被窃取时也不用担心泄密；2)对原始数据使用MD5算法产生数字指纹，当从分布式存储系统取回数据时，计算数字指纹并与本地的数字指纹对比，就可以判断数据是否被篡改。
Algorithms for image processing and computer vision
Parker, J R
2010-01-01
A cookbook of algorithms for common image processing applications Thanks to advances in computer hardware and software, algorithms have been developed that support sophisticated image processing without requiring an extensive background in mathematics. This bestselling book has been fully updated with the newest of these, including 2D vision methods in content-based searches and the use of graphics cards as image processing computational aids. It's an ideal reference for software engineers and developers, advanced programmers, graphics programmers, scientists, and other specialists wh
Ionosphere correction algorithm for spaceborne SAR imaging
Lin Yang; Mengdao Xing; Guangcai Sun
2016-01-01
For spaceborne synthetic aperture radar (SAR) ima-ging, the dispersive ionosphere has significant effects on the pro-pagation of the low frequency (especial y P-band) radar signal. The ionospheric effects can be a significant source of the phase error in the radar signal, which causes a degeneration of the image quality in spaceborne SAR imaging system. The background ionospheric effects on spaceborne SAR through modeling and simulation are analyzed, and the qualitative and quantitative analysis based on the spatio-temporal variability of the ionosphere is given. A novel ionosphere correction algorithm (ICA) is proposed to deal with the ionospheric effects on the low frequency spaceborne SAR radar signal. With the proposed algorithm, the degradation of the image quality caused by the ionosphere is corrected. The simulation re-sults show the effectiveness of the proposed algorithm.
A Self-synchronizing Stream Encryption Scheme Based on One-Dimensional Coupled Map Lattices
MA Hui; ZHU Kai-En; CHEN Tian-Lun
2007-01-01
We present a self-synchronizing stream encryption scheme based on one-dimensional coupled map lattices which is introduced as a model with the essential features of spatiotemporal chaos,and of great complexity and diffusion capability of the little disturbance in the initial condition.To evaluate the scheme,a series of statistical tests are employed,and the results show good random-look nature of the ciphertext.Furthermore,we apply our algorithm to encrypt a grey-scale image to show the key sensitivity.
朱兴锋
2011-01-01
为了实现一个高效的加密算法,本文充分利用图形处理器(GPU)的并行处理能力,提出基于CUDA实现IDEA加密算法的方法,对该方法的设计和实现进行详细的阐述,并通过实验与传统的基于CPU的实现方法进行性能比较,基于CUDA的IDEA实现速度上远远高于基于CPU的实现.%With the parallel processing capability of Graphics Processing Unit (GPU) , design and implementation of IDEA algo-rithm is proposed as an efficient encryption and decryption algorithm, which is elaborated in this paper. Both traditional CPU-based and new one based on GPU are implemented. At last, the performance based on GPU is analyzed, which runs much faster than the traditional approach.
Fast SAR Imaging Algorithm for FLGPR
无
2007-01-01
A fast SAR imaging algorithm for near- field subsurface forward-looking ground penetrating radar (FLGPR) is presented. By using nonstationary convolution filter, the refocused image spectrum can be reconstructed directly from the backscattered signal spectrum of target area. The experimental results show the proposed method can fast achieve image refocusing. Also it has higher computational efficiency than the phase-shift migration approach and the delay-and-sum (DAS) approach.
An Efficient Image Steganographic Algorithm
M. Shobana
2015-01-01
Steganography assumes a key part in the mystery information (computerized) correspondence. The pattern of consolidating mystery picture in Cover picture is begat as Image-Image Steganography. Most presumably all pictures are part into red, green and blue layers, But here sequestered from everything reason, the spread's layers picture are spitting into Cyan, Magenta, Yellow and key (Black). On the establishment of these four shading layers, three calculations have been arranged and...
Encryption And Portable Data Storage
Cynthia L. Knott
2011-04-01
Full Text Available The protection of data is key issue in today’s world. The wide of availability and use of portable technologies such as USB flash has increased concern about securing the data resides on these devices. Because USB flash drives are small, relatively inexpensive, and easy to use, the security of the information stored on these thumb drives is on-going concern. A number of approaches to safeguarding the information stored on these drives are available. This paper examines one approach to this goal through the use of encryption. This method encrypts all the data on the drive. In addition the fact the data on the drive is encrypted is not visually obvious when viewing the contents of the disk. The proposed approach uses publically available and free encryption algorithms. A user password is needed to view and access the data that has been encrypted. The proposed methodology is quick and easy to use. Individuals who routinely carry around their USB drives need to be able to decrypt and encrypt the device quickly and conveniently. Furthermore, if the device is lost, it is still possible with the method advocated in this paper to include information about how to return the device to the owner without compromising the secured data on the drive. Without encrypting the data on portable drives, the user risks the disclosure of information. This paper argues that portable storage should be secured and suggests a way to secure the data through password and encryption that further enhances the usability and flexibility of the USB flash drive. The paper includes the results and analysis of an undergraduate student survey that determined what habits and practices they followed with respect to securing their personal data and files. Some of the questions included in the analysis are the following: Do you encrypt your USB flash drive?Do you use any type of security for your USB flash drive?How important do you think security is for a flash drive? (A
谢会娟; 韩昌豪; 吴明珠
2014-01-01
随着互联网的发展，云计算模式能够提供便捷的、可用的和按需要网络资源，云计算的核心是如何存储和管理用户的数据，除了配置存储设备的之外，还要考虑到存储在云中的数据的安全性。RSA加密算法是基于一个比较简单的数论-两个大素数相乘十分容易实现，但要对它的乘积进行因式分解却十分困难，RSA加密算法是将乘积公开作为加密密钥的非对称加密方法，在云计算中应用RSA算法对存储在云中的数据进行加密，能够保证了数据的安全性。%With the development of the Internet, cloud computing can provide convenient and available network resources, the core of cloud computing is how to store and manage user data, cloud computing does not provide storage devices, but also takes into account the security of the data stored in the cloud. RSA encryption algorithm is based on a relatively simple theory of math-multiplying two large prime numbers is very easy to achieve, but it's the factorization is very difficult, RSA encryption al⁃gorithm considers a product as a public encryption key and is an asymmetric encryption method. To ensure the security of the da⁃ta, RSA encryption algorithm is applied for the data storage in the cloud.
Image Recovery Algorithm Based on Learned Dictionary
Xinghui Zhu
2014-01-01
Full Text Available We proposed a recovery scheme for image deblurring. The scheme is under the framework of sparse representation and it has three main contributions. Firstly, considering the sparse property of natural image, the nonlocal overcompleted dictionaries are learned for image patches in our scheme. And, then, we coded the patches in each nonlocal clustering with the corresponding learned dictionary to recover the whole latent image. In addition, for some practical applications, we also proposed a method to evaluate the blur kernel to make the algorithm usable in blind image recovery. The experimental results demonstrated that the proposed scheme is competitive with some current state-of-the-art methods.
Optical image encryption based on gyrator transformation and chaotic function%基于回转器变换和混沌的光图像加密
孔德彭; 杜学文; 孔德辉
2012-01-01
提出一种基于混沌理论和回转器的光图像加密技术,它由混沌函数产生的随机相位掩膜对光学系统进行加密和解密.利用三种混沌函数对比研究,它们分别是改进的Logistic映射、Hybrid映射和Baker映射,给出了基于混沌理论与光学系统研究思路和方法,通过盲加密、旋转角度的盲解密来证实其鲁棒性与可靠性,借助计算机进行了模拟,证实了光学加密和解密实施可行性,最后给出了均方差的有效性.%The paper proposed a novel method of optical image encryption based on gyrator transformation and chaos theory. The random phase masks generated by chaotic function is used to encrypt and decrypt the optical system. In this method, the three kinds of chaotic functions are compared and studied. They can improve the Logistic mapping, Hybrid mapping and Baker mapping respectively. It gives research idea and method based on chaos theory and optical system. Its robustness and reliability is proved by blind encryption and the blind decryption of the rotation angle. Through the simulation on computer, the feasibility of the optical encryption and decryption is proved and the validity of the mean square error is given finally.
Dermoscopic Image Segmentation using Machine Learning Algorithm
L. P. Suresh
2011-01-01
Full Text Available Problem statement: Malignant melanoma is the most frequent type of skin cancer. Its incidence has been rapidly increasing over the last few decades. Medical image segmentation is the most essential and crucial process in order to facilitate the characterization and visualization of the structure of interest in medical images. Approach: This study explains the task of segmenting skin lesions in Dermoscopy images based on intelligent systems such as Fuzzy and Neural Networks clustering techniques for the early diagnosis of Malignant Melanoma. The various intelligent system based clustering techniques used are Fuzzy C Means Algorithm (FCM, Possibilistic C Means Algorithm (PCM, Hierarchical C Means Algorithm (HCM; C-mean based Fuzzy Hopfield Neural Network, Adaline Neural Network and Regression Neural Network. Results: The segmented images are compared with the ground truth image using various parameters such as False Positive Error (FPE, False Negative Error (FNE Coefficient of similarity, spatial overlap and their performance is evaluated. Conclusion: The experimental results show that the Hierarchical C Means algorithm( Fuzzy provides better segmentation than other (Fuzzy C Means, Possibilistic C Means, Adaline Neural Network, FHNN and GRNN clustering algorithms. Thus Hierarchical C Means approach can handle uncertainties that exist in the data efficiently and useful for the lesion segmentation in a computer aided diagnosis system to assist the clinical diagnosis of dermatologists.
An Efficient Image Steganographic Algorithm
M Shobana
2015-12-01
Full Text Available Steganography assumes a key part in the mystery information (computerized correspondence. The pattern of consolidating mystery picture in Cover picture is begat as Image-Image Steganography. Most presumably all pictures are part into red, green and blue layers, But here sequestered from everything reason, the spread's layers picture are spitting into Cyan, Magenta, Yellow and key (Black. On the establishment of these four shading layers, three calculations have been arranged and inspected in an effective way. In this calculation pixel intensities stand in a critical spot to choose its inserting limit. To assess the bore of the got picture its PSNR and MSE has been computed.
CONSTRUCTION OF THE ENCRYPTION MATRIX BASED ON CHEBYSHEV CHAOTIC NEURAL NETWORKS
Zou Ajin; Wu Wei; Li Renfa; Li Yongjiang
2012-01-01
The paper proposes a novel algorithm to get the encryption matrix.Firstly,a chaotic sequence generated by Chebyshev chaotic neural networks is converted into a series of low-order integer matrices from which available encryption matrices are selected.Then,a higher order encryption matrix relating real world application is constructed by means of tensor production method based on selected encryption matrices.The results show that the proposed algorithm can produce a "one-time pad cipher" encryption matrix with high security; and the encryption results have good chaos and autocorrelation with the natural frequency of the plaintext being hidden and homogenized.
Image fusion algorithm using nonsubsampled contourlet transform
Xiao, Yang; Cao, Zhiguo; Wang, Kai; Xu, Zhengxiang
2007-11-01
In this paper, a pixel-level image fusion algorithm based on Nonsubsampled Contourlet Transform (NSCT) has been proposed. Compared with Contourlet Transform, NSCT is redundant, shift-invariant and more suitable for image fusion. Each image from different sensors could be decomposed into a low frequency image and a series of high frequency images of different directions by multi-scale NSCT. For low and high frequency images, they are fused based on local-contrast enhancement and definition respectively. Finally, fused image is reconstructed from low and high frequency fused images. Experiment demonstrates that NSCT could preserve edge significantly and the fusion rule based on region segmentation performances well in local-contrast enhancement.
Universal lossless compression algorithm for textual images
al Zahir, Saif
2012-03-01
In recent years, an unparalleled volume of textual information has been transported over the Internet via email, chatting, blogging, tweeting, digital libraries, and information retrieval systems. As the volume of text data has now exceeded 40% of the total volume of traffic on the Internet, compressing textual data becomes imperative. Many sophisticated algorithms were introduced and employed for this purpose including Huffman encoding, arithmetic encoding, the Ziv-Lempel family, Dynamic Markov Compression, and Burrow-Wheeler Transform. My research presents novel universal algorithm for compressing textual images. The algorithm comprises two parts: 1. a universal fixed-to-variable codebook; and 2. our row and column elimination coding scheme. Simulation results on a large number of Arabic, Persian, and Hebrew textual images show that this algorithm has a compression ratio of nearly 87%, which exceeds published results including JBIG2.
QR code optical encryption using spatially incoherent illumination
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.
Performance evaluation of image segmentation algorithms on microscopic image data.
Beneš, Miroslav; Zitová, Barbara
2015-01-01
In our paper, we present a performance evaluation of image segmentation algorithms on microscopic image data. In spite of the existence of many algorithms for image data partitioning, there is no universal and 'the best' method yet. Moreover, images of microscopic samples can be of various character and quality which can negatively influence the performance of image segmentation algorithms. Thus, the issue of selecting suitable method for a given set of image data is of big interest. We carried out a large number of experiments with a variety of segmentation methods to evaluate the behaviour of individual approaches on the testing set of microscopic images (cross-section images taken in three different modalities from the field of art restoration). The segmentation results were assessed by several indices used for measuring the output quality of image segmentation algorithms. In the end, the benefit of segmentation combination approach is studied and applicability of achieved results on another representatives of microscopic data category - biological samples - is shown.
Image Mosaicing Algorithm for Rolled Fingerprint Construction
贺迪; 荣钢; 周杰
2002-01-01
Fingerprint identification is one of the most important biometric authentication methods. However, current devices for recording digital fingerprints can only capture plain-touch fingerprints. Rolled fingerprints have much more information for recognition, so a method is needed to construct a rolled fingerprint from a series of plain-touch fingerprints. This paper presents a novel algorithm for image mosaicing for real time rolled fingerprint construction in which the images are assembled with corrections to create a smooth, non-fragmented rolled fingerprint in real time. Experimental results demonstrate its effectiveness by comparing it with other conventional algorithms.
Algorithm for Fast Registration of Radar Images
Subrata Rakshit
2002-07-01
Full Text Available Radar imagery provides an all-weather and 24 h coverage, making it ideal for critical defence applications. In some applications, multiple images acquired of an area need to be registered for further processing. Such situations arise for battlefield surveillance based on satellite imagery. The registration has to be done between an earlier (reference image and a new (live image. For automated surveillance, registration is a prerequisite for change detection. Speed is essential due to large volumes of data involved and the need for quick responses. The registration transformation is quite simple, being mainly a global translation. (Scale and rotation corrections can be applied based on known camera parameters. The challenge lies in the fact that the radar images are not as feature-rich as optical images and the image content variation can be as high as 90 per cent. Even though the change on the ground may not be drastic, seasonal variations can significantly alter the radar signatures of ground, vegetation, and water bodies. This necessitates a novel approach different from the techniques developed for optical images. An algorithm has been developed that leads to fast registration of radar images, even in the presence of specular noise and significant scene content variation. The key features of this approach are adaptability to sensor/terrain types, ability to handle large content variations and false positive rejection. The present work shows that this algorithm allows for various cost-performance trade-offs, making it suitable for a wide variety of applications. The algorithm, in various cost-performance configurations, is tested on a set of ERS images. Results of such tests have been reported, indicating the performance of the algorithm for various cost-performance trade-offs.
刘银森
2011-01-01
针对目前混沌加密算法重于理论研究的现实,结合 P2P 网络传输结构的安全隐患,以 Windows Peer-to-Peer Networking 平台的 Graph 模块为基础,设计了一种运用混沌加密算法进行通信数据加密的 P2P 保密视频会议方案.方案在 P2P 网络结构采用 CA 机制,在网络传输结构上层采用混沌加密算法以及动态密钥管理,构建视频会议的安全环境.在实现该方案基础上探索了混沌加密算法的可用性.%Focusing on the reality of chaotic encryption algorithms more often appearing in theory, combining with the security risks of P2P network structure, this paper provides a new P2P secure video conferencing solution based on the Graph module of WPPN and a chaotic encryption algorithm. The application of CA mechanism inside P2P network structure and chaotic encryption with dynamic key management on data transmission creates a secure environment for video conference. After the realization of this solution, it probes a fact that the chaotic encryption algorithm is available.
A High-Throughput Hardware Implementation of XTS-AES Encryption Algorithm%高吞吐率XTS-AES加密算法的硬件实现
李子磊; 刘政林; 霍文捷; 邹雪城
2011-01-01
This paper proposes a new hardware implementation method for XTS-AES Algorithm that has a full parallel pipelined structure. The proposal scheme increases throughput by unrolling the data path. Meanwhile, it also improves the circuit clock frequency and overall performance by using inner pipelined structure to optimize the critical path. Compared with the currently known highest throughput XTS-AES implementation, the new XTS-AES module increases the throughput by 52. 28％ in UMC 90 nm CMOS technology. The result indicates that this hardware module fully meets the need of high-speed encrypted storage at present.%基于XTS-AES算法提出了一种具有并行全流水结构的硬件实现方法.设计通过展开数据通路的方式,提高了吞吐率;同时还通过采用内部流水线结构优化关键路径的方式,提高了电路的时钟频率和整体工作性能.在UMC 90 nm CMOS工艺条件下,所设计的XTS-AES模块的吞吐率比目前已知XTS-AES的最高吞吐率提高了52.28%.分析结果表明,该硬件模块完全满足现阶段高速加密存储的需要.
SEMI-FRAGILE WATERMARKING ALGORITHM FOR IMAGE TAMPERS LOCALIZATION AND RECOVERY
Jiang Xuemei; Liu Quan
2008-01-01
Two watermarks are embedded into the original image. One is the authentication watermark generated by secret key, which is embedded into the sub-LSB (Least Significant Bit) of the original image for tamper localization; the other is the recovery watermark for tamper recovering. The original image is divided into 8×8 blocks and each block is transformed by Discrete Cosine Transform(DCT). For each block, some lower frequency DCT coefficients are chosen to be quantized and binary encoded so as to gain the recovery watermark of each block, and the recovery watermark is embedded into the LSB of another block by chaos encryption and authentication chain technology. After the two watermarks being detected, the location of any minute changes in image can be detected, and the tampered image data can be recovered effectively. In the paper, the number of coefficients and their bit lengths are carefully chosen in order to satisfy with the payload of each block and gain the capability of self-recovering. The proposed algorithm can well resist against possible forged attacks. Experimental results show that the watermark generated by the proposed algorithm is sensitive to tiny changes in images, and it has higher accuracy of tamper localization and good capability of the tamper recovery.
2007-03-01
Half LUT design. The final design was developed by Satyanarayana and follows an algorithm created by Trenholme, which implements MixColumns using...MixColumns labeled “Half LUT” can be found in Appendix B. 3.9.2.2 Arithmetic The final design is due to Satyanarayana following an algorithm...highlighted above) could be eliminated. The VHDL code in Figure 22 was written by Satyanarayana and effectively implements the xtime function in
Dynamic Data Updating Algorithm for Image Superresolution Reconstruction
TAN Bing; XU Qing; ZHANG Yan; XING Shuai
2006-01-01
A dynamic data updating algorithm for image superesolution is proposed. On the basis of Delaunay triangulation and its local updating property, this algorithm can update the changed region directly under the circumstances that only a part of the source images has been changed. For its high efficiency and adaptability, this algorithm can serve as a fast algorithm for image superesolution reconstruction.
An edge detection algorithm for imaging ladar
Qi Wang(王骐); Ziqin Li(李自勤); Qi Li(李琦); Jianfeng Sun(孙剑峰); Juncheng Fu(傅俊诚)
2003-01-01
In this paper, the morphological filter based on parametric edge detection is presented and applied toimaging ladar image with speckle noise. This algorithm and Laplacian of Gaussian (LOG) operator arecompared on edge detection. The experimental results indicate the superior performance of this kind ofthe edge detection.
ALGORITHMIC IMAGING APPROACH TO IMPOTENCE
Mahyar Ghafoori
2012-05-01
Full Text Available Impotence is a common problem that has great impact on the quality of life. Clinical evaluation usually can exclude endocrinologic imbalance, neurogenic dysfunction, and psychological problems as the etiology. A patient who fails to get an erection after vasoactive medications which are injected probably, has hemodynamic impotence. Dynamic studies that include imaging techniques are now available to discriminate between arterial and venous pathology.Doppler ultrasound with color flow and spectral analysis,dynamic infusion corpus cavernosometry and cavernosography, and selective internal pudendal arteriography are outpatient diagnostic procedures that will differentiate, image and quantify the abnormalities in patients with hemodynamic impotence. Not all tests are needed in every patient. Each of these examinations is preceded with the intracavernosal injection of vasoactive medication. Papaverine hydrochloride, phentolamine mesylate, or prostaglandin El will overcome normal sympathetic tone and produce an erection by smooth muscle relaxation and arterial dilatation in a normal patient. Color-flow Doppler and spectral analysis will showthe cavernosal arteries and can identify the hemodynamic effects of stricture or occlusion. Peak systolic velocity is measured. Normal ranges are well established. Spectral analysis also is used to predict the presence of venous disease. Sizable venous leaks in the dorsal penile vein are readily imaged.While the technique may not adequately identify low-grade venous pathology, it will identify the size and location of fibrous plaque formation associated with Peyronie's disease. Cavernosography or cavernosometry is a separate procedure that will quantitate the severity of venousincompetence as well as specifically identify the various avenues of systemic venous return that must be localized if venous occlusive therapy is chosen. In this study, the peak arterial systolic occlusion pressure is quantified during
An algorithm of image segmentation for overlapping grain image
WANG Zhi; JIN Guang; SUN Xiao-wei
2005-01-01
Aiming at measurement of granularity size of nonmetal grain, an algorithm of image segmentation and parameter calculation for microscopic overlapping grain image was studied. This algorithm presents some new attributes of graph sequence from discrete attribute of graph,and consequently achieves the geometrical characteristics from input graph, and the new graph sequence in favor of image segmentation is recombined. The conception that image edge denoted with "twin-point" is put forward, base on geometrical characters of point, image edge is transformed into serial edge, and on recombined serial image edge, based on direction vector definition of line and some additional restricted conditions, the segmentation twin-points are searched with, thus image segmentation is accomplished. Serial image edge is transformed into twin-point pattern, to realize calculation of area and granularity size of nonmetal grain. The inkling and uncertainty on selection of structure element which base on mathematical morphology are avoided in this algorithm, and image segmentation and parameter calculation are realized without changing grain's self statistical characters.
Experimental Study of Fractal Image Compression Algorithm
Chetan R. Dudhagara
2012-08-01
Full Text Available Image compression applications have been increasing in recent years. Fractal compression is a lossy compression method for digital images, based on fractals. The method is best suited for textures and natural images, relying on the fact that parts of an image often resemble other parts of the same image. In this paper, a study on fractal-based image compression and fixed-size partitioning will be made, analyzed for performance and compared with a standard frequency domain based image compression standard, JPEG. Sample images will be used to perform compression and decompression. Performance metrics such as compression ratio, compression time and decompression time will be measured in JPEG cases. Also the phenomenon of resolution/scale independence will be studied and described with examples. Fractal algorithms convert these parts into mathematical data called "fractal codes" which are used to recreate the encoded image. Fractal encoding is a mathematical process used to encode bitmaps containing a real-world image as a set of mathematical data that describes the fractal properties of the image. Fractal encoding relies on the fact that all natural, and most artificial, objects contain redundant information in the form of similar, repeating patterns called fractals.
Signal and reference wave dually encrypted digital holographic system
ZHU YiChao; ZHANG JiaSen; GONG QiHuang
2008-01-01
We propose a secure digital holographic system with signal and reference waves dually encrypted. Two random phase masks are used to encrypt the images in the input and the Fourier planes. The reference beam is phase encoded by another random phase mask. The encrypted image and the key are recorded by a CCD camera. The data can be processed or transferred directly by computer. We theoretically and experimentally demonstrate encryption and decryption of multiple images and the results show a high quality and good fault tolerance.
Digital image processing an algorithmic approach with Matlab
Qidwai, Uvais
2009-01-01
Introduction to Image Processing and the MATLAB EnvironmentIntroduction Digital Image Definitions: Theoretical Account Image Properties MATLAB Algorithmic Account MATLAB CodeImage Acquisition, Types, and File I/OImage Acquisition Image Types and File I/O Basics of Color Images Other Color Spaces Algorithmic Account MATLAB CodeImage ArithmeticIntroduction Operator Basics Theoretical TreatmentAlgorithmic Treatment Coding ExamplesAffine and Logical Operations, Distortions, and Noise in ImagesIntroduction Affine Operations Logical Operators Noise in Images Distortions in ImagesAlgorithmic Account
基于时间的 RFID 加密传输算法的研究%Encrypted Transmission Algorithm of RFID Based on Time
盛魁
2015-01-01
无线射频识别系统由于其便捷、价廉的特点，发展十分迅速，在社会生活中起到越来越重要的作用，其信息安全问题受到越来越多的关注。针对传输过程中标签信息安全问题，提出一种基于时间的 RFID 加密传输算法，有效解决 RFID 标签信息的安全问题。理论分析和仿真结果表明该算法具有良好的稳定性、安全性和较高的传输效率及易于实现等优点。%Radio frequency identification (RFID)system is developing rapidly due to its characteris-tics of convenience and cheapness,playing a more and more important role in social life.The problem of its information security has attracted great attention.On the problem of security of tag information in the process of transmission, this paper presents an algorithm based on the RFID encryption transmission time,effectively solving the security problem of the RFID tag information.Theoretical analysis and simu-lation results show that the algorithm has good stability and security,high transmission efficiency and be-ing easy to realize.
Image completion algorithm based on texture synthesis
Zhang Hongying; Peng Qicong; Wu Yadong
2007-01-01
A new algorithm is proposed for completing the missing parts caused by the removal of foreground or background elements from an image of natural scenery in a visually plausible way.The major contributions of the proposed algorithm are: (1) for most natural images, there is a strong orientation of texture or color distribution.So a method is introduced to compute the main direction of the texture and complete the image by limiting the search to one direction to carry out image completion quite fast; (2) there exists a synthesis ordering for image completion.The searching order of the patches is denned to ensure the regions with more known information and the structures should be completed before filling in other regions; (3) to improve the visual effect of texture synthesis, an adaptive scheme is presented to determine the size of the template window for capturing the features of various scales.A number of examples are given to demonstrate the effectiveness of the proposed algorithm.
LSB Based Quantum Image Steganography Algorithm
Jiang, Nan; Zhao, Na; Wang, Luo
2016-01-01
Quantum steganography is the technique which hides a secret message into quantum covers such as quantum images. In this paper, two blind LSB steganography algorithms in the form of quantum circuits are proposed based on the novel enhanced quantum representation (NEQR) for quantum images. One algorithm is plain LSB which uses the message bits to substitute for the pixels' LSB directly. The other is block LSB which embeds a message bit into a number of pixels that belong to one image block. The extracting circuits can regain the secret message only according to the stego cover. Analysis and simulation-based experimental results demonstrate that the invisibility is good, and the balance between the capacity and the robustness can be adjusted according to the needs of applications.
于英政; 许宏丽
2014-01-01
With the wide application of two‐dimensional code, two‐dimensional code encryption technology has attracted more and more attention. QR(Quick Response) two‐dimensional code is a widely used two‐dimensional code. The different stages of the implementation procedure have different characteristics. This paper presents a multilevel fusion encryption algo‐rithm based on QR code, greatly improved the encryption intensity of QR code by using DES and fixed keys RC4 encryption in different stages. This algorithm does not significantly increase the length and the processing time of QR code. The experi‐mental data show the validity of the algorithm.%随着二维码的广泛应用，二维码加密技术受到越来越多的关注。快速响应（Quick Response ，QR）二维码是一种被广泛使用的二维码，其实现过程的不同阶段有不同的特点。论文提出一种基于QR二维码的多级融合加密算法概念，通过对不同阶段采取DES加密和固定密钥的RC4加密大大提高QR二维码的加密强度，同时不明显增加二维码的长度和处理时间。实验数据表明了论文所提算法的有效性。
赵新阳; 郭杰; 周斌
2016-01-01
为了提高数据传输过程的安全性,笔者对国密对称密码算法( SM4 )的多模式实现机制进行研究,分析了模式间的差异和适用场景,统一了多模式编程接口. 宝钢集团有限公司ESB平台与基于云存储技术的网络文件保护系统集成时,采用基于电文密码本( ECB)模式的SM4密码算法实现消息传输的双向加解密,很好地解决了企业系统集成中的信息安全问题.%In order to improve the security of message transmission,the multi encryption modes of the SM4 Block Cipher algorithm are researched, the differences among these encryption modes and the suitable application scenario for each encryption mode are analyzed, and a unified multi-mode pro-gramming interface is provided. When integrating the ESB platform with the TSP system,which is a network file protection system based on the cloud storage technology,in Baosteel Group Corporation, the SM4 Block Cipher algorithm with ECB encryption mode is used to ensure the security of message transmission,which solves the problem of information security in enterprise system integration.
Guohua Zou
2016-12-01
Full Text Available New medical imaging technology, such as Computed Tomography and Magnetic Resonance Imaging (MRI, has been widely used in all aspects of medical diagnosis. The purpose of these imaging techniques is to obtain various qualitative and quantitative data of the patient comprehensively and accurately, and provide correct digital information for diagnosis, treatment planning and evaluation after surgery. MR has a good imaging diagnostic advantage for brain diseases. However, as the requirements of the brain image definition and quantitative analysis are always increasing, it is necessary to have better segmentation of MR brain images. The FCM (Fuzzy C-means algorithm is widely applied in image segmentation, but it has some shortcomings, such as long computation time and poor anti-noise capability. In this paper, firstly, the Ant Colony algorithm is used to determine the cluster centers and the number of FCM algorithm so as to improve its running speed. Then an improved Markov random field model is used to improve the algorithm, so that its antinoise ability can be improved. Experimental results show that the algorithm put forward in this paper has obvious advantages in image segmentation speed and segmentation effect.
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.
Encrypting Binary Bits via Quantum Cryptography
ZENGGuihua
2004-01-01
A quantum cryptographic algorithm, which may be exploited to encrypt classic information is investigated theoretically in this paper. The proposed algorithm can prevent quantum attack strategy as well as classic attack strategy. A proof-in-principle of experimental demonstration, which exploits optical fibre communication technology and photon technology, is suggested.
A modified algorithm for SAR parallel imaging
HU Ju-rong; WANG Fei; CAO Ning; LU Hao
2009-01-01
Synthetic aperture radar can provide two dimension images by converting the acquired echoed SAR signal to targets coordinate and reflectivity. With the advancement of sophisticated SAR signal processing, more and more SAR imaging methods have been proposed for synthetic aperture radar which works at near field and the Fresnel approximation is not appropriate. Time domain correlation is a kind of digital reconstruction method based on processing the synthetic aperture radar data in the two-dimensional frequency domain via Fourier transform. It reconstructs SAR image via simply correlation without any need for approximation or interpolation. But its high computational cost for correlation makes it unsuitable for real time imaging. In order to reduce the computational burden a modified algorithm about time domain correlation was given in this paper. It also can take full advantage of parallel computations of the imaging processor. Its practical implementation was proposed and the preliminary simulation results were presented. Simulation results show that the proposed algorithm is a computationally efficient way of implementing the reconstruction in real time SAR image processing.
An Efficient Encryption Algorithm for P2P Networks Robust Against Man-in-the-Middle Adversary
Roohallah Rastaghi
2012-11-01
Full Text Available Peer-to-peer (P2P networks have become popular as a new paradigm for information exchange and are being used in many applications such as file sharing, distributed computing, video conference, VoIP, radio and TV broadcasting. This popularity comes with security implications and vulnerabilities that need to be addressed. Especially duo to direct communication between two end nodes in P2P networks, these networks are potentially vulnerable to Man-in-the-Middle attacks. In this paper, we propose a new public-key cryptosystem for P2P networks that is robust against Man-in-the-Middle adversary. This cryptosystem is based on RSA and knapsack problems. Our precoding-based algorithm uses knapsack problem for performing permutation and padding random data to the message. We show that comparing to other proposed cryptosystems, our algorithm is more efficient and it is fully secure against an active adversary.
Three-dimensional information encryption and anticounterfeiting using digital holography.
Shiu, Min-Tzung; Chew, Yang-Kun; Chan, Huang-Tian; Wong, Xin-Yu; Chang, Chi-Ching
2015-01-01
In this work, arbitrary micro phase-step digital holography with optical interferometry and digital image processing is utilized to obtain information about an image of a three-dimensional object and encrypting keys. Then, a computer-generated hologram is used for the purpose of holographic encryption. All information about the keys is required to perform the decryption, comprising the amplitude and phase distribution of the encrypting key, the distance of image reconstruction, zero-order term elimination, and twin-image term suppression. In addition to using identifiable information on different image planes and linear superposition processing hidden within the encrypted information, not only can we convey an important message, but we can also achieve anticounterfeiting. This approach retains the strictness of traditional holographic encryption and the convenience of digital holographic processing without image distortion. Therefore, this method provides better solutions to earlier methods for the security of the transmission of holographic information.
Endmember extraction algorithms from hyperspectral images
M. C. Cantero
2006-06-01
Full Text Available During the last years, several high-resolution sensors have been developed for hyperspectral remote sensing applications. Some of these sensors are already available on space-borne devices. Space-borne sensors are currently acquiring a continual stream of hyperspectral data, and new efficient unsupervised algorithms are required to analyze the great amount of data produced by these instruments. The identification of image endmembers is a crucial task in hyperspectral data exploitation. Once the individual endmembers have been identified, several methods can be used to map their spatial distribution, associations and abundances. This paper reviews the Pixel Purity Index (PPI, N-FINDR and Automatic Morphological Endmember Extraction (AMEE algorithms developed to accomplish the task of finding appropriate image endmembers by applying them to real hyperspectral data. In order to compare the performance of these methods a metric based on the Root Mean Square Error (RMSE between the estimated and reference abundance maps is used.
Triple Encrypted Holographic Storage and Digital Holographic System
ZHU Yi-Chao; ZHANG Jia-Sen; GONG Qi-Huang
2008-01-01
We propose a triple encrypted holographic memory containing a digital holographic system. The original image is encrypted using double random phase encryption and stored in a LiNbO3:Fe crystal with shift-multiplexing. Both the reference beams of the memory and the digital holographic system are random phase encoded. We theoretically and experimentally demonstrate the encryption and decryption of multiple images and the results show high quality and good fault tolerance. The total key length of this system is larger than 4.7×1033.
Advanced Homomorphic Encryption its Applications and Derivatives (AHEAD)
2013-09-01
plaintext attacks, and let Enc(K, ·),Dec(K, ·) denote the encryption/decryption algorithms with key K. Encrypted cuckoo table. An encrypted cuckoo table [25...20] consists of three arrays (T1, T2, S) that hold ciphertexts of some fixed length. The arrays T1 and T2 are both of size m and serve as cuckoo -hash...rebuilds. We will assume an oblivious protocol for the following task. At the start of the protocol, the server holds encrypted cuckoo hash tables C1
于娜娜
2012-01-01
基于傅里叶计算全息技术,结合菲涅尔双随机相位加密系统,提出了一种数字图像加密方法。该方法以傅里叶计算全息图记录菲涅尔衍射双随机相位加密图像,傅里叶计算全息加密图像隐藏了原图像大小尺度信息,而且再现多个图像,必须针对加密图像共轭方可解密,提高了图像加密的安全性,并且解决了普通方法加密图像难存储的问题,作为原始明文的拥有者,两个随机相位板,应用波长,两次菲涅尔衍射的距离都可作为解密密钥。%A new method of digital image encryption using Fourier CGH,combined the Fresnel dual randomized phase encryption system is proposed.In this method the encryption images of Fresnel diffraction two random phases system is recorded by Fourier CGH,The Fourier CGH is an image without size scale information of the original image and many images representation,but the decryption must according to the conjugate of original encryption,so this method greatly enhances the image encryption security.As the owner of the original image,three phase plate,application wavelength,twice the distance of the Fresnel diffraction can serve as decryption keys.
A Novel Approach to Fast Image Filtering Algorithm of Infrared Images based on Intro Sort Algorithm
Gupta, Kapil Kumar; Niranjan, Jitendra Kumar
2012-01-01
In this study we investigate the fast image filtering algorithm based on Intro sort algorithm and fast noise reduction of infrared images. Main feature of the proposed approach is that no prior knowledge of noise required. It is developed based on Stefan- Boltzmann law and the Fourier law. We also investigate the fast noise reduction approach that has advantage of less computation load. In addition, it can retain edges, details, text information even if the size of the window increases. Intro sort algorithm begins with Quick sort and switches to heap sort when the recursion depth exceeds a level based on the number of elements being sorted. This approach has the advantage of fast noise reduction by reducing the comparison time. It also significantly speed up the noise reduction process and can apply to real-time image processing. This approach will extend the Infrared images applications for medicine and video conferencing.
Naji, A W; Zaidan, B B; Al-Khateeb, Wajdi F; Khalifa, Othman O; Zaidan, A A; Gunawan, Teddy S
2009-01-01
The hurried development of multimedia and internet allows for wide distribution of digital media data. It becomes much easier to edit, modify and duplicate digital information. In additional, digital document is also easy to copy and distribute, therefore it may face many threats. It became necessary to find an appropriate protection due to the significance, accuracy and sensitivity of the information. Furthermore, there is no formal method to be followed to discover a hidden data. In this paper, a new information hiding framework is presented.The proposed framework aim is implementation of framework computation between advance encryption standard (AES) and distortion technique (DT) which embeds information in image page within executable file (EXE file) to find a secure solution to cover file without change the size of cover file. The framework includes two main functions; first is the hiding of the information in the image page of EXE file, through the execution of four process (specify the cover file, spec...
Relaxation Algorithm of Piecing-Error for Sub-Images
LI Yueping; TANG Pushan
2001-01-01
During the process of automatic image recognition or automatic reverse design of IC, people often encounter the problem that some sub-images must be pieced together into a whole image. In the traditional piecing algorithm for sub images, a large accumulated error will be made. In this paper, a relaxation algorithm of piecing-error for sub-images is presented. It can eliminate the accumulated error in the traditional algorithm and greatly improve the quality of pieced image. Based on an initial pieced image, one can continuously adjust the center of every sub-image and its angle to lessen the error between the adjacent sub-images, so the quality of pieced image can be improved. The presented results indicate that the proposed algorithm can dramatically decrease the error while the quality of ultimate pieced image is still acceptable. The time complexity of this algorithm is O(n In n).
Digital Signature and Watermark Methods For Image Authentication using Cryptography Analysis
M.Sreerama Murty
2011-06-01
Full Text Available The digital signature and watermarking methods are used for image authentication. Digital signature encodes the signature in a file separate from the original image. Cryptographic algorithms have suggested several advantages over the traditional encryption algorithms such as high security, speed, reasonablecomputational overheads and computational power. A digital watermark and signature method for image authentication using cryptography analysis is proposed. The digital signature created for the originalimage and apply watermark. Images are resized before transmission in the network. After digital signature and water marking an image, apply the encryption and decryption process to an image for the authentication. The encryption is used to securely transmit data in open networks for the encryption of an image using public key and decrypt that image using private key.
Digital Signature and Watermark Methods For Image Authentication using Cryptography Analysis
M.Sreerama Murty
2011-09-01
Full Text Available The digital signature and watermarking methods are used for image authentication. Digital signature encodes the signature in a file separate from the original image. Cryptographic algorithms have suggested several advantages over the traditional encryption algorithms such as high security, speed, reasonablecomputational overheads and computational power. A digital watermark and signature method for image authentication using cryptography analysis is proposed. The digital signature created for the originalimage and apply watermark. Images are resized before transmission in the network. After digital signature and water marking an image, apply the encryption and decryption process to an image for the authentication. The encryption is used to securely transmit data in open networks for the encryption of an image using public key and decrypt that image using private key.
Image Searching within Another Image Using Image Matching and Genetic Algorithms
Mehmet Karakoc
2015-10-01
Full Text Available Main focus of this work is to realize image searching within another image in an efficient way. Image searching within another image is accomplished through the integrated use of image matching techniques and searching algorithms. Artificial neural networks along with various image features such as average color value, color standard deviation, correlation and edge parameters are used for image matching whereas genetic algorithms were used for image searching. In the work presented in this paper, an integrated method based on smart searching algorithms, quick image matching methods and parallel programming techniques were proposed and implemented. Proposed method was tested on several low and high-resolution reference and template images. Results revealed that the proposed method can successfully match images and significantly reduce the total search time.
周小红; 周建伙
2015-01-01
With the development of Internet technology,information security is becoming more and more popular.This pa-per introduces the basic principle of the MD5 encryption algorithm.The application of MD5 encryption algorithm in the regis-tration and login verification module in the.NET environment through Visual C# is introduced in detail.The security of MD5 al-gorithm is analyzed.Final y,put forward and realize the improvement method.%随着互联网技术的发展，信息安全越来越受到人们的关注。介绍了MD5加密算法的基本原理，详细介绍如何在。 NET环境下通过Visual C＃实现MD5加密算法在注册及登录验证模块中的应用。分析MD5算法的安全性，最后提出并实现自己的改进方法。
Study on Airspace Covert Communication Algorithm of Covert Communication System
Yinpu Zhang
2012-04-01
Full Text Available Based on the security of information transmission through network in the information society, the paper puts forward covert communication technology which is more reliable than the prior encryption algorithm, analyzes channel covertness and information hiding of covert communication technology based on spread-spectrum communication technology, and establishes a covert communication system including image steganalysis, Arnold transformation and scrambling of carrier image, embedding of secret information, generation of encrypted image and recovering of carrier image by image-based covert communication technology. The simulation result shows: in order to ensure there is no serious degrading problem after embedding the secret information, the carrier image must have a large capacity; the larger the scrambling times is, the better the scrambling and encrypting effect is. Therefore, the airspace covert communication algorithm based on spread-spectrum communication technology well achieves safe transmission of information and has good application prospect.
A new semi-fragile watermarking algorithm for image authentication
HAN De-zhi; HU Yu-ping
2005-01-01
This paper presents a new semi-fragile watermarking algorithm for image authentication which extracts image features from the low frequency domain to generate two watermarks: one for classifying of the intentional content modification and the other for indicating the modified location. The algorithm provides an effective mechanism for image authentication. The watermark generation and watermark embedment are disposed in the image itself, and the received image authentication needs no information about the original image or watermark. The algorithm increases watermark security and prevents forged watermark. Experimental results show that the algorithm can identify intentional content modification and incidental tampering, and also indicate the location where a modification takes place.
Relaxation Algorithm of Piecing—Error for Sub—Images
李跃平; 唐璞山
2001-01-01
During the process of automatic image recognition or automatic reverse design of IC,people often encounter the problem that some sub-images must be pieced together into a whole image,In the traditional piecing algorithm for subimages,a large accumulated error will be made.In this paper,a relaxation algorithm of piecing -error for sub-images is presented.It can eliminate the accumulated error in the traditional algorithm and greatly improve the quality of pieced image.Based on an initial pieced image,one can continuously adjust the center of every sub-image and its angle to lessen the error between the adjacent sub-images,so the quality of pieced image can be improved.The presented results indicate that the proposed algorithm can dramatically decrease the error while the quality of ultimate pieced image is still acceptable.The time complexity of this algorithm is O(nlnn).
Kumar, Pramod; Joseph, Joby; Singh, Kehar
2011-05-01
Interference-based optical encryption schemes have an inherent silhouette problem due to the equipollent nature of the phase-only masks (POMs) generated using an analytical method. One of the earlier methods suggested that removing the problem by use of exchanging process between two masks increases the computational load. This shortcoming is overcome with a noniterative method using the jigsaw transformation (JT) in a single step, with improved security because the inverse JT of these masks, along with correct permutation keys that are necessary to decrypt the original image. The stringent alignment requirement of the POMs in two different arms during the experiment is removed with an alternative method using a single spatial light modulator. Experimental results are provided to demonstrate the decryption process with the proposed method.
Image Processing Algorithms – A Comprehensive Study
Mahesh Prasanna K
2014-06-01
Full Text Available Digital image processing is an ever expanding and dynamic area with applications reaching out into our everyday life such as medicine, space exploration, surveillance, authentication, automated industry inspection and many more areas. These applications involve different processes like image enhancement and object detection [1]. Implementing such applications on a general purpose computer can be easier, but not very time efficient due to additional constraints on memory and other peripheral devices. Application specific hardware implementation offers much greater speed than a software implementation. With advances in the VLSI (Very Large Scale Integrated technology hardware implementation has become an attractive alternative. Implementing complex computation tasks on hardware and by exploiting parallelism and pipelining in algorithms yield significant reduction in execution times [2].
The Watershed Algorithm for Image Segmentation
OU Yan; LIN Nan
2007-01-01
This article introduced the watershed algorithm for the segmentation, illustrated the segmation process by implementing this algorithm. By comparing with another three related algorithm, this article revealed both the advantages and drawbacks of the watershed algorithm.
Improved Bat Algorithm Applied to Multilevel Image Thresholding
Adis Alihodzic
2014-01-01
Full Text Available Multilevel image thresholding is a very important image processing technique that is used as a basis for image segmentation and further higher level processing. However, the required computational time for exhaustive search grows exponentially with the number of desired thresholds. Swarm intelligence metaheuristics are well known as successful and efficient optimization methods for intractable problems. In this paper, we adjusted one of the latest swarm intelligence algorithms, the bat algorithm, for the multilevel image thresholding problem. The results of testing on standard benchmark images show that the bat algorithm is comparable with other state-of-the-art algorithms. We improved standard bat algorithm, where our modifications add some elements from the differential evolution and from the artificial bee colony algorithm. Our new proposed improved bat algorithm proved to be better than five other state-of-the-art algorithms, improving quality of results in all cases and significantly improving convergence speed.
Inverse synthetic aperture radar imaging principles, algorithms and applications
Chen , Victor C
2014-01-01
Inverse Synthetic Aperture Radar Imaging: Principles, Algorithms and Applications is based on the latest research on ISAR imaging of moving targets and non-cooperative target recognition (NCTR). With a focus on the advances and applications, this book will provide readers with a working knowledge on various algorithms of ISAR imaging of targets and implementation with MATLAB. These MATLAB algorithms will prove useful in order to visualize and manipulate some simulated ISAR images.
Distributed Searchable Symmetric Encryption
Bösch, Christoph; Peter, Andreas; Leenders, Bram; Lim, Hoon Wei; Tang, Qiang; Wang, Huaxiong; Hartel, Pieter; Jonker, Willem
2014-01-01
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
Area Optimized Advanced Encryption Standard
Mr. Sandip R. Aher
2014-08-01
Full Text Available Performance evaluation of the Advanced Encryption Standard candidates has become led to intensive study of both hardware and software implementations. However, number of papers presents various implementation results, it shows that efficiency could still be greatly improved by applying effective design rules adapted to devices and algorithms. This paper shows various approaches for efficient FPGA implementations of the Advanced Encryption Standard algorithm. For different applications of the AES algorithm may require different s peed/area tradeoffs, we propose a vital study of the possible implementation schemes, but also the discussion of design methodology and algorithmic optimization in order to improve previous reported results. We propose system to evaluate hardware efficiency at different steps of the design process. We also use an optimal pipeline that takes the place and route constraints into account. Resulting circuits significantly improve the previous reported results: throughput has been up to 18.5 Gbits/sec and the area requirements can be limited to 542 slices and 10 RAM blocks with a ratio throughput/area improved by minimum 25% of the best-known designs in the Xilinx Virtex- E technology.
Chu Jianli
2013-09-01
Full Text Available This article designs a new mobile-phone entrance guard system, uses the encryption two-dimensional code for identity authentication. Different from other similar products in the market, this system does not rely on specialized mobile phone card or NFC (near field communication module. It can be directly realized through mobile-phone software, and it can be operated simple and safer. This article designs the whole system model, includes structure, function and workflow. It also analyzes and researches the main algorithms used in the system, which include security policy algorithm, encryption two-dimensional code algorithm and image recognition algorithm. Finally, it provides the solution method for the problem in the experimental simulation. It also evaluated and summarized the experimental results.
Li, Jianzhong
2014-04-21
In this paper, a novel secure optimal image watermarking scheme using an encrypted gyrator transform computer generated hologram (CGH) in the contourlet domain is presented. A new encrypted CGH technique, which is based on the gyrator transform, the random phase mask, the three-step phase-shifting interferometry and the Fibonacci transform, has been proposed to produce a hologram of a watermark first. With the huge key space of the encrypted CGH, the security strength of the watermarking system is enhanced. To achieve better imperceptibility, an improved quantization embedding algorithm is proposed to embed the encrypted CGH into the low frequency sub-band of the contourlet-transformed host image. In order to obtain the highest possible robustness without losing the imperceptibility, particle swarm optimization algorithm is employed to search the optimal embedding parameter of the watermarking system. In comparison with other method, the proposed watermarking scheme offers better performances for both imperceptibility and robustness. Experimental results demonstrate that the proposed image watermarking is not only secure and invisible, but also robust against a variety of attacks.
Steganography Algorithm to Hide Secret Message inside an Image
Ibrahim, Rosziati
2011-01-01
In this paper, the authors propose a new algorithm to hide data inside image using steganography technique. The proposed algorithm uses binary codes and pixels inside an image. The zipped file is used before it is converted to binary codes to maximize the storage of data inside the image. By applying the proposed algorithm, a system called Steganography Imaging System (SIS) is developed. The system is then tested to see the viability of the proposed algorithm. Various sizes of data are stored inside the images and the PSNR (Peak signal-to-noise ratio) is also captured for each of the images tested. Based on the PSNR value of each images, the stego image has a higher PSNR value. Hence this new steganography algorithm is very efficient to hide the data inside the image.
PARAMETRIC EVALUATION ON THE PERFORMANCE OF VARIOUS IMAGE COMPRESSION ALGORITHMS
V. Sutha Jebakumari; P. Arockia Jansi Rani
2011-01-01
Wavelet analysis plays a vital role in the signal processing especially in image compression. In this paper, various compression algorithms like block truncation coding, EZW and SPIHT are studied and ana- lyzed; its algorithm idea and steps are given. The parameters for all these algorithms are analyzed and the best parameter for each of these compression algorithms is found out.
PARAMETRIC EVALUATION ON THE PERFORMANCE OF VARIOUS IMAGE COMPRESSION ALGORITHMS
V. Sutha Jebakumari
2011-05-01
Full Text Available Wavelet analysis plays a vital role in the signal processing especially in image compression. In this paper, various compression algorithms like block truncation coding, EZW and SPIHT are studied and ana- lyzed; its algorithm idea and steps are given. The parameters for all these algorithms are analyzed and the best parameter for each of these compression algorithms is found out.
Photonic encryption using all optical logic.
Blansett, Ethan L.; Schroeppel, Richard Crabtree; Tang, Jason D.; Robertson, Perry J.; Vawter, Gregory Allen; Tarman, Thomas David; Pierson, Lyndon George
2003-12-01
cascaded in an encrypting/scrambling algorithm based on a study of candidate encryption algorithms. We found that a low gate count, cascadable encryption algorithm is most feasible given device and processing constraints. The modeling and simulation of optical designs using these components is proceeding in parallel with efforts to perfect the physical devices and their interconnect. We have applied these techniques to the development of a 'toy' algorithm that may pave the way for more robust optical algorithms. These design/modeling/simulation techniques are now ready to be applied to larger optical designs in advance of our ability to implement such systems in hardware.
郑之华
2012-01-01
This paper describes the MD5 encryption algorithm and its working principle, puts forward the application and implementatio of MD5 encryption algorithm in the anthentication of the user management system based on LDAP, and suggestions for improvement ideas.%介绍了MD5加密算法及其工作原理，提出了MD5在基于LDAP的统一用户管理系统中身份认证的应用和实现，并提出了改进思想。
Clutter discrimination algorithm simulation in pulse laser radar imaging
Zhang, Yan-mei; Li, Huan; Guo, Hai-chao; Su, Xuan; Zhu, Fule
2015-10-01
Pulse laser radar imaging performance is greatly influenced by different kinds of clutter. Various algorithms are developed to mitigate clutter. However, estimating performance of a new algorithm is difficult. Here, a simulation model for estimating clutter discrimination algorithms is presented. This model consists of laser pulse emission, clutter jamming, laser pulse reception and target image producing. Additionally, a hardware platform is set up gathering clutter data reflected by ground and trees. The data logging is as clutter jamming input in the simulation model. The hardware platform includes a laser diode, a laser detector and a high sample rate data logging circuit. The laser diode transmits short laser pulses (40ns FWHM) at 12.5 kilohertz pulse rate and at 905nm wavelength. An analog-to-digital converter chip integrated in the sample circuit works at 250 mega samples per second. The simulation model and the hardware platform contribute to a clutter discrimination algorithm simulation system. Using this system, after analyzing clutter data logging, a new compound pulse detection algorithm is developed. This new algorithm combines matched filter algorithm and constant fraction discrimination (CFD) algorithm. Firstly, laser echo pulse signal is processed by matched filter algorithm. After the first step, CFD algorithm comes next. Finally, clutter jamming from ground and trees is discriminated and target image is produced. Laser radar images are simulated using CFD algorithm, matched filter algorithm and the new algorithm respectively. Simulation result demonstrates that the new algorithm achieves the best target imaging effect of mitigating clutter reflected by ground and trees.
Prototype for Meta-Algorithmic, Content-Aware Image Analysis
2015-03-01
49 ii LIST OF FIGURES Figure 1: Flow of process creating the BoW histogram...automated segmentation algorithms. The GUI has the option to select the algorithms and also the image to segment. The left hand panel displays the...image selected and the right panel displays the image with the segments. .......................................................... 16 Figure 5: Shows a
Efficient predictive algorithms for image compression
Rosário Lucas, Luís Filipe; Maciel de Faria, Sérgio Manuel; Morais Rodrigues, Nuno Miguel; Liberal Pagliari, Carla
2017-01-01
This book discusses efficient prediction techniques for the current state-of-the-art High Efficiency Video Coding (HEVC) standard, focusing on the compression of a wide range of video signals, such as 3D video, Light Fields and natural images. The authors begin with a review of the state-of-the-art predictive coding methods and compression technologies for both 2D and 3D multimedia contents, which provides a good starting point for new researchers in the field of image and video compression. New prediction techniques that go beyond the standardized compression technologies are then presented and discussed. In the context of 3D video, the authors describe a new predictive algorithm for the compression of depth maps, which combines intra-directional prediction, with flexible block partitioning and linear residue fitting. New approaches are described for the compression of Light Field and still images, which enforce sparsity constraints on linear models. The Locally Linear Embedding-based prediction method is in...
A Transport Model of Mobile Agent Based on Secure Hybrid Encryption
SUNZhixin; CHENZhixian; WANGRuchuan
2005-01-01
The solution of security problems of mobile agents is a key issue, which will decide whether mobile agents can be widely used. The paper analyzes main security problems, which currently are confronted with mobile agent systems and existing protection solutions. And then the paper presents a Security Transport model of mobile agents based on a hybrid encryption algorithm (TMSHE).Meanwhile, it expatiates on implementation of the algorithm. The algorithm of TMSHE model mainly consists of two parts, i.e., employing a hybrid encryption algorithm to encrypt mobile agents and using Transport layer security (TLS) to encrypt communication channel. Mobile agents by hybrid encryption move through communication channels, which are encrypted by TLS. The simulation results indicate that the model can protect mobile agents' security effectively, and consequently the security and steadiness of the whole mobile agent system are also improved. The model has succeeded in getting application in a prototypesystem- Intrusion detection system based on mobile agents.
孔德照; 林超; 沈学举; 王昕; 周晗
2013-01-01
提出一种基于小波包变换(WPT)的分数阶光学图像加密方法.利用WPT能够对图像多层次分解的特性,结合分数傅里叶变换(FRFT)的灵活性,将双随机相位、小波函数的类型及尺度因子和分数阶次作为密钥,实现了图像的多重密钥加解密.同时,实现了图像小波域上的选择性加密,使加密样式变得更灵活多样,还增强了加密图像的抵抗恶意的攻击能力.数值模拟了加密和解密过程,分析了加密效果和解密图像质量,验证了本文方法的可行性.%A novel method for the optical image encryption is presented, which is based on the wavelet packet transform (WPT) and fractional Fourier transform (FRFT). The idea of combining WPT with FRFT comes from the study of properties of them. Images can be decomposed by wavelet packet transform. With the increase in the order of WPT,the image will be decomposed into more parts,of which each contains the essential information. Based on the good property of WPT and the flexibility of FRFT, the method implicates encryption and decryption of the image and produces many keys, consisting of double random phase masks,the order of WPT and the order of FRFT. Meanwhile,the selected-image-encryption in wavlet domain is realized in this paper,which varies the patterns of encryptioa The method improves the security,and the ability of resisting malicious attacks is also enhanced. The encryption and decryption are implicated by numerical simulation. The result of the simulation provides the requirement for analyzing the properties of encryption and decryptioa The feasibility and simplicity of the method are verified by numerical simulation,and a simple optical implication of the method is also proposed. Based on the numerical simulation and theroy analysis,it can be confluded that the method for the optical image encryption is novel and effective.
Improving night sky star image processing algorithm for star sensors.
Arbabmir, Mohammad Vali; Mohammadi, Seyyed Mohammad; Salahshour, Sadegh; Somayehee, Farshad
2014-04-01
In this paper, the night sky star image processing algorithm, consisting of image preprocessing, star pattern recognition, and centroiding steps, is improved. It is shown that the proposed noise reduction approach can preserve more necessary information than other frequently used approaches. It is also shown that the proposed thresholding method unlike commonly used techniques can properly perform image binarization, especially in images with uneven illumination. Moreover, the higher performance rate and lower average centroiding estimation error of near 0.045 for 400 simulated images compared to other algorithms show the high capability of the proposed night sky star image processing algorithm.
Spatially adaptive regularized iterative high-resolution image reconstruction algorithm
Lim, Won Bae; Park, Min K.; Kang, Moon Gi
2000-12-01
High resolution images are often required in applications such as remote sensing, frame freeze in video, military and medical imaging. Digital image sensor arrays, which are used for image acquisition in many imaging systems, are not dense enough to prevent aliasing, so the acquired images will be degraded by aliasing effects. To prevent aliasing without loss of resolution, a dense detector array is required. But it may be very costly or unavailable, thus, many imaging systems are designed to allow some level of aliasing during image acquisition. The purpose of our work is to reconstruct an unaliased high resolution image from the acquired aliased image sequence. In this paper, we propose a spatially adaptive regularized iterative high resolution image reconstruction algorithm for blurred, noisy and down-sampled image sequences. The proposed approach is based on a Constrained Least Squares (CLS) high resolution reconstruction algorithm, with spatially adaptive regularization operators and parameters. These regularization terms are shown to improve the reconstructed image quality by forcing smoothness, while preserving edges in the reconstructed high resolution image. Accurate sub-pixel motion registration is the key of the success of the high resolution image reconstruction algorithm. However, sub-pixel motion registration may have some level of registration error. Therefore, a reconstruction algorithm which is robust against the registration error is required. The registration algorithm uses a gradient based sub-pixel motion estimator which provides shift information for each of the recorded frames. The proposed algorithm is based on a technique of high resolution image reconstruction, and it solves spatially adaptive regularized constrained least square minimization functionals. In this paper, we show that the reconstruction algorithm gives dramatic improvements in the resolution of the reconstructed image and is effective in handling the aliased information. The
Siddhartha Mukherjee
2014-04-01
Full Text Available This paper gives a detailed study on the performance of image filter algorithm with various parameters applied on an image of RGB model. There are various popular image filters, which consumes large amount of computing resources for processing. Oil paint image filter is one of the very interesting filters, which is very performance hungry. Current research tries to find improvement in oil paint image filter algorithm by using parallel pattern library. With increasing kernel-size, the processing time of oil paint image filter algorithm increases exponentially. I have also observed in various blogs and forums, the questions for faster oil paint have been asked repeatedly.
Chatterjee, Sanjit
2011-01-01
Identity Based Encryption (IBE) is a type of public key encryption and has been intensely researched in the past decade. Identity-Based Encryption summarizes the available research for IBE and the main ideas that would enable users to pursue further work in this area. This book will also cover a brief background on Elliptic Curves and Pairings, security against chosen Cipher text Attacks, standards and more. Advanced-level students in computer science and mathematics who specialize in cryptology, and the general community of researchers in the area of cryptology and data security will find Ide
Generic Adaptively Secure Searchable Phrase Encryption
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.
A review of iterative phase retrieval for measurement and encryption
Guo, Cheng; Wei, Ce; Tan, Jiubin; Chen, Kana; Liu, Shutian; Wu, Qun; Liu, Zhengjun
2017-02-01
Phase retrieval technique is regarded as one of the most significant tools to solve optical inverse problems. Several phase retrieval algorithms are discussed in this review. The occurrence of ill-posed conditions often makes the calculation difficult. As a synthesis, the multiple-image phase retrieval technology is invented to obtain more accurate convergence result in iterative computation. The multiple-input retrieval scheme can attach new constraints on convergence as a new limitation. As an indirect measuring method, it will make it possible to reconstruct the distribution of intensity and phase in an imaging or measurement system, where data processing is executed by computer. Moreover, the retrieval method has been applied for image encryption successfully. Finally, the development and application of the iterative phase retrieval are overviewed.
Video Encryption Based on Chaotic Systems in the Compression Domain
Ali Abdulgader
2012-01-01
Full Text Available With the development of the internet and multimedia technology digital video encryption has attracted a great deal of research interest in the recent few years in applications. In this paper, we propose a method to encrypt video data. The proposed algorithm is based on the MPEG video coding standard. It selectively encrypts some DCT coefficients in the I frame, B frame and P frame in MPEG video compression by using chaotic systems. The key in this paper is chaotic sequence based on logistic mapping. It can produce the pseudo-random sequences with good randomness. The experimental results based on chaotic maps prove the effectiveness of the proposed method, showing advantages of large key space and high-level security. The proposed algorithm was measured through a series of tests and achieved good results. The results indicate that the algorithm can be implemented for video encryption efficiently and it provides considerable levels of security.
Manimala, Jose Mathew
2010-01-01
The evolution of encryption algorithms have led to the development of very complicated and highly versatile algorithms that sacrifice efficiency for better and harder to decrypt results. But by the application of a genetic schema to the encryption of data, a new structure can be created. Genetic methods and procedures are lethal in the way they handle and manipulate data. The RAmM algorithm uses four genetic operations that have been developed specifically for encryption of data. The operations are Replication, Augmentation, Mutation and Multiplication. The proper application of these methods according to the rules that have been found to be the best for getting optimal and correct results produces a "fingerprint" that is unique to a pair of . This means that every single data entry can only be decrypted by using the correct set of key. The application of the RAmM algorithm is in the field of image encryption and restoration. The boundary and the pixel values are separately encrypted to produce a very genuine...
Chaos-Based Simultaneous Compression and Encryption for Hadoop.
Usama, Muhammad; Zakaria, Nordin
2017-01-01
Data compression and encryption are key components of commonly deployed platforms such as Hadoop. Numerous data compression and encryption tools are presently available on such platforms and the tools are characteristically applied in sequence, i.e., compression followed by encryption or encryption followed by compression. This paper focuses on the open-source Hadoop framework and proposes a data storage method that efficiently couples data compression with encryption. A simultaneous compression and encryption scheme is introduced that addresses an important implementation issue of source coding based on Tent Map and Piece-wise Linear Chaotic Map (PWLM), which is the infinite precision of real numbers that result from their long products. The approach proposed here solves the implementation issue by removing fractional components that are generated by the long products of real numbers. Moreover, it incorporates a stealth key that performs a cyclic shift in PWLM without compromising compression capabilities. In addition, the proposed approach implements a masking pseudorandom keystream that enhances encryption quality. The proposed algorithm demonstrated a congruent fit within the Hadoop framework, providing robust encryption security and compression.
Chaos-Based Simultaneous Compression and Encryption for Hadoop
Zakaria, Nordin
2017-01-01
Data compression and encryption are key components of commonly deployed platforms such as Hadoop. Numerous data compression and encryption tools are presently available on such platforms and the tools are characteristically applied in sequence, i.e., compression followed by encryption or encryption followed by compression. This paper focuses on the open-source Hadoop framework and proposes a data storage method that efficiently couples data compression with encryption. A simultaneous compression and encryption scheme is introduced that addresses an important implementation issue of source coding based on Tent Map and Piece-wise Linear Chaotic Map (PWLM), which is the infinite precision of real numbers that result from their long products. The approach proposed here solves the implementation issue by removing fractional components that are generated by the long products of real numbers. Moreover, it incorporates a stealth key that performs a cyclic shift in PWLM without compromising compression capabilities. In addition, the proposed approach implements a masking pseudorandom keystream that enhances encryption quality. The proposed algorithm demonstrated a congruent fit within the Hadoop framework, providing robust encryption security and compression. PMID:28072850
Encrypted Data Storage in EGEE
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...
Encrypting Analytical Web Applications
Fuhry, Benny; Tighzert, Walter; Kerschbaum. Florian
2016-01-01
The software-as-a-service (SaaS) market is growing very fast, but still many clients are concerned about the confidentiality of their data in the cloud. Motivated hackers or malicious insiders could try to steal the clients’ data. Encryption is a potential solution, but supporting the necessary functionality also in existing applications is difficult. In this paper, we examine encrypting analytical web applications that perform extensive number processing operations in the database. Existing ...
Homomorphic encryption and applications
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
Performance analysis of Non Linear Filtering Algorithms for underwater images
Padmavathi, Dr G; Kumar, Mr M Muthu; Thakur, Suresh Kumar
2009-01-01
Image filtering algorithms are applied on images to remove the different types of noise that are either present in the image during capturing or injected in to the image during transmission. Underwater images when captured usually have Gaussian noise, speckle noise and salt and pepper noise. In this work, five different image filtering algorithms are compared for the three different noise types. The performances of the filters are compared using the Peak Signal to Noise Ratio (PSNR) and Mean Square Error (MSE). The modified spatial median filter gives desirable results in terms of the above two parameters for the three different noise. Forty underwater images are taken for study.
Automated Photogrammetric Image Matching with Sift Algorithm and Delaunay Triangulation
Karagiannis, Georgios; Antón Castro, Francesc/François; Mioc, Darka
2016-01-01
An algorithm for image matching of multi-sensor and multi-temporal satellite images is developed. The method is based on the SIFT feature detector proposed by Lowe in (Lowe, 1999). First, SIFT feature points are detected independently in two images (reference and sensed image). The features...... of each feature set for each image are computed. The isomorphism of the Delaunay triangulations is determined to guarantee the quality of the image matching. The algorithm is implemented in Matlab and tested on World-View 2, SPOT6 and TerraSAR-X image patches....
陈作新
2012-01-01
The encryption means this paper puts forward is an improvement and application of AES for digital library.By using initial values of logistic map as the cipherkey seeds to create chaotic sequences and then carrying on quantification with its proper region value,the binary system cipherkey streams can be obtained.The initial cipherkey of AES can be produced by dividing the binary streams into groups,and one-time-pad is realized with the algorithm.The improved algorithm is applicable in the digital library through length equalization by patching on the plain text with dynamic cipher,and time complexity reduction by degrading the number of encrypting rounds.The results of simulation verify the correctness of the algorithm and the high sensitivity of cryptograph to cipherkey.%提出的加密方案是AES算法在数字图书馆中的应用和改进。改进的新算法采用Logistic映射初值作为种子密钥生成混沌序列,对该序列进行域值量化得到二进制密钥流,对其分组作为AES算法的初始密钥,实现了一次一密;通过用动态密码对明文修补,实现密文与明文的长度相同;通过减少加密轮次,降低其时间复杂度,从而使其在数字图书馆数据加密系统中的应用可行。计算机仿真结果验证了该算法的正确性以及密文对密钥的高度敏感性。
An improved SIFT algorithm based on KFDA in image registration
Chen, Peng; Yang, Lijuan; Huo, Jinfeng
2016-03-01
As a kind of stable feature matching algorithm, SIFT has been widely used in many fields. In order to further improve the robustness of the SIFT algorithm, an improved SIFT algorithm with Kernel Discriminant Analysis (KFDA-SIFT) is presented for image registration. The algorithm uses KFDA to SIFT descriptors for feature extraction matrix, and uses the new descriptors to conduct the feature matching, finally chooses RANSAC to deal with the matches for further purification. The experiments show that the presented algorithm is robust to image changes in scale, illumination, perspective, expression and tiny pose with higher matching accuracy.
A Hyper Modern Cryptography Algorithm to Improved Data Security: HMCA
Vishwa Gupta
2011-12-01
Full Text Available In this paper, we propose an improved block cipher symmetric encryption algorithm that has the same structure of encryption and decryption. So far, conventional cryptography algorithms have difference structure of encryption and decryption. We devise our algorithm by inserting a symmetric layer using random number, encryption number and XOR operations, in which the whole proposed algorithm rounds uses encryption procedure and the same for it decryption procedure. The symmetry layer is put between encryption part and decryption one. The proposed algorithm has the batter speed compared with the comparing encryption algorithm. Nevertheless, the proposed algorithm improves encryption security by inserting the symmetric layer. The proposed algorithm will be useful to the applications which require the same procedure of encryption and decryption
A new parallel algorithm for image matching based on entropy
董开坤; 胡铭曾
2001-01-01
Presents a new parallel image matching algorithm based on the concept of entropy feature vector and suitable to SIMD computer, which, in comparison with other algorithms, has the following advantages: ( 1 ) The spatial information of an image is appropriately introduced into the definition of image entropy. (2) A large number of multiplication operations are eliminated, thus the algorithm is sped up. (3) The shortcoming of having to do global calculation in the first instance is overcome, and concludes the algorithm has very good locality and is suitable for parallel processing.
Image segmentation by using the localized subspace iteration algorithm
2008-01-01
An image segmentation algorithm called"segmentation based on the localized subspace iterations"(SLSI)is proposed in this paper.The basic idea is to combine the strategies in Ncut algorithm by Shi and Malik in 2000 and the LSI by E,Li and Lu in 2007.The LSI is applied to solve an eigenvalue problem associated with the affinity matrix of an image,which makes the overall algorithm linearly scaled.The choices of the partition number,the supports and weight functions in SLSI are discussed.Numerical experiments for real images show the applicability of the algorithm.
A Review of Spaceborne SAR Algorithm for Image Formation
Li Chun-sheng
2013-03-01
Full Text Available This paper firstly reviews the history and trends in development of spaceborne Synthetic Aperture Radar (SAR satellite technology in American and European countries. Besides, the basic information of the launched satellites and the future satellite plans are introduced. Then this paper summaries and assorts the imaging algorithm of spaceborn SAR satellite and analyzes the advantages and disadvantages of each algorithm. Moreover, the scope and the application status of each algorithm are presented. And then the paper elaborates trends of SAR imaging algorithm, which mainly introduces the algorithms based on compressive sensing theory and new image modes, and the results of simulation are also illustrated. At last, the paper summaries the development direction of spaceborne SAR imaging algorithm.
An Efficient Quantum Somewhat Homomorphic Symmetric Searchable Encryption
Sun, Xiaoqiang; Wang, Ting; Sun, Zhiwei; Wang, Ping; Yu, Jianping; Xie, Weixin
2017-01-01
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.
An Efficient Quantum Somewhat Homomorphic Symmetric Searchable Encryption
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.
Optical color image hiding scheme based on chaotic mapping and Hartley transform
Liu, Zhengjun; Zhang, Yu; Liu, Wei; Meng, Fanyi; Wu, Qun; Liu, Shutian
2013-08-01
We present a color image encryption algorithm by using chaotic mapping and Hartley transform. The three components of color image are scrambled by Baker mapping. The coordinates composed of the scrambled monochrome components are converted from Cartesian coordinates to spherical coordinates. The data of azimuth angle is normalized and regarded as the key. The data of radii and zenith angle are encoded under the help of optical Hartley transform with scrambled key. An electro-optical encryption structure is designed. The final encrypted image is constituted by two selected color components of output in real number domain.
Li, Li; Xiao, Wei; Jian, Weijian
2014-11-20
Three-dimensional (3D) laser imaging combining compressive sensing (CS) has an advantage in lower power consumption and less imaging sensors; however, it brings enormous stress to subsequent calculation devices. In this paper we proposed a fast 3D imaging reconstruction algorithm to deal with time-slice images sampled by single-pixel detectors. The algorithm implements 3D imaging reconstruction before CS recovery, thus it saves plenty of runtime of CS recovery. Several experiments are conducted to verify the performance of the algorithm. Simulation results demonstrated that the proposed algorithm has better performance in terms of efficiency compared to an existing algorithm.
Image hash algorithm based on chaos theory%一种基于混沌的图像hash算法
肖潇; 胡春强; 邓绍江
2011-01-01
To meet the needs of the Image Authentication, proposed image hash algorithm based on chaos theory. To begin with ,encrypted the original image by Logistic map. After that, difference matrix was modulated and quantified, and then obtained the fixed length of hash sequence. It discussed that the image scaling and JPEG compression were influence on the robustness of the hash sequence. It pointed that robust of the proposed scheme against the above attacks when the threshold t is 0.1. The experimental results indicate that the algorithm has the robust to against the above attacks, then the method is an effective for studying image authentication.%为了实现图像认证,提出了基于混沌理论的图像hash算法.首先将原始图像经过置乱得到加密图像,然后对差值矩阵进行调制、量化,得到固定长度的图像hash序列.算法讨论了图像的缩放和JPEG压缩对图像hash序列的影响,当阈值为0.1时,对上述的攻击方法进行了实验,结果表明,图像对这两种攻击具有一定的鲁棒性.
Research on Encryption Mechanism of Ethernet Passive Optical Network
XU Wei-liang; FAN hong
2006-01-01
An ethernet-passive-optical-network consists of one optical-line-terminator and multiple optical-network-units oith passive optical components. The network is susceptible to variable security threats. In this paper we propose a security model and an encryption layer placed at reconciliation sublayer. We also propose advanced encryption standard as an ideal cipher algorithm to encrypt downstream data . We then discuss three different methods to solve the problem of the last plaintext group, and the methods are realized on digital signal processing. Finally, we study efficiency and delay issues of the three methods.
AN IMPROVED FUZZY CLUSTERING ALGORITHM FOR MICROARRAY IMAGE SPOTS SEGMENTATION
V.G. Biju
2015-11-01
Full Text Available An automatic cDNA microarray image processing using an improved fuzzy clustering algorithm is presented in this paper. The spot segmentation algorithm proposed uses the gridding technique developed by the authors earlier, for finding the co-ordinates of each spot in an image. Automatic cropping of spots from microarray image is done using these co-ordinates. The present paper proposes an improved fuzzy clustering algorithm Possibility fuzzy local information c means (PFLICM to segment the spot foreground (FG from background (BG. The PFLICM improves fuzzy local information c means (FLICM algorithm by incorporating typicality of a pixel along with gray level information and local spatial information. The performance of the algorithm is validated using a set of simulated cDNA microarray images added with different levels of AWGN noise. The strength of the algorithm is tested by computing the parameters such as the Segmentation matching factor (SMF, Probability of error (pe, Discrepancy distance (D and Normal mean square error (NMSE. SMF value obtained for PFLICM algorithm shows an improvement of 0.9 % and 0.7 % for high noise and low noise microarray images respectively compared to FLICM algorithm. The PFLICM algorithm is also applied on real microarray images and gene expression values are computed.
Fast image matching algorithm based on projection characteristics
Zhou, Lijuan; Yue, Xiaobo; Zhou, Lijun
2011-06-01
Based on analyzing the traditional template matching algorithm, this paper identified the key factors restricting the speed of matching and put forward a brand new fast matching algorithm based on projection. Projecting the grayscale image, this algorithm converts the two-dimensional information of the image into one-dimensional one, and then matches and identifies through one-dimensional correlation, meanwhile, because of normalization has been done, when the image brightness or signal amplitude increasing in proportion, it could also perform correct matching. Experimental results show that the projection characteristics based image registration method proposed in this article could greatly improve the matching speed, which ensuring the matching accuracy as well.
High performance deformable image registration algorithms for manycore processors
Shackleford, James; Sharp, Gregory
2013-01-01
High Performance Deformable Image Registration Algorithms for Manycore Processors develops highly data-parallel image registration algorithms suitable for use on modern multi-core architectures, including graphics processing units (GPUs). Focusing on deformable registration, we show how to develop data-parallel versions of the registration algorithm suitable for execution on the GPU. Image registration is the process of aligning two or more images into a common coordinate frame and is a fundamental step to be able to compare or fuse data obtained from different sensor measurements. E
The Noise Clinic: a Blind Image Denoising Algorithm
Marc Lebrun
2015-01-01
Full Text Available This paper describes the complete implementation of a blind image algorithm, that takes any digital image as input. In a first step the algorithm estimates a Signal and Frequency Dependent (SFD noise model. In a second step, the image is denoised by a multiscale adaptation of the Non-local Bayes denoising method. We focus here on a careful analysis of the denoising step and present a detailed discussion of the influence of its parameters. Extensive commented tests of the blind denoising algorithm are presented, on real JPEG images and scans of old photographs.
An optical encryption scheme that uses polarization of coherent light
Gopinathan, Unnikrishnan; David S. Monaghan; Naughton, Thomas J.; Sheridan, John T.
2005-01-01
We demonstrate an optical system that encodes two dimensional data as different polarization states. The encrypted image is recorded using a digital holographic setup and the decryption is done numerically.
Encryption as a Service using Parallel Computing Frameworks
Alexandru Costin Stanimir
2013-12-01
Full Text Available In this article I present a study of an implementation named Encryption as a service which is a web service that can be deployed on a various number of devices and that can take advantage of parallelism in order to provide basic functionality of a cryptographic system: encrypt, decrypt and store data. This goal was achieved by implementing symmetric key cryptography algorithm Advanced Encryption Standard (AES using Open Computing Language (OpenCL and exposed this functionality through a REST web service .The performance results were obtained by deploying this solution on Windows Azure platform in order to take advantage of 20x CPU computing power m Amazon Web Service platform equipped with 2x Nvidia Tesla K20 GPU and regular home user hardware. This study represents a first step in a broader project which final goal is to provide full support for all encryption algorithms.
A beamforming algorithm for bistatic SAR image formation.
Yocky, David Alan; Wahl, Daniel Eugene; Jakowatz, Charles V., Jr.
2010-03-01
Beamforming is a methodology for collection-mode-independent SAR image formation. It is essentially equivalent to backprojection. The authors have in previous papers developed this idea and discussed the advantages and disadvantages of the approach to monostatic SAR image formation vis--vis the more standard and time-tested polar formatting algorithm (PFA). In this paper we show that beamforming for bistatic SAR imaging leads again to a very simple image formation algorithm that requires a minimal number of lines of code and that allows the image to be directly formed onto a three-dimensional surface model, thus automatically creating an orthorectified image. The same disadvantage of beamforming applied to monostatic SAR imaging applies to the bistatic case, however, in that the execution time for the beamforming algorithm is quite long compared to that of PFA. Fast versions of beamforming do exist to help alleviate this issue. Results of image reconstructions from phase history data are presented.
A beamforming algorithm for bistatic SAR image formation
Jakowatz, Charles V., Jr.; Wahl, Daniel E.; Yocky, David A.
2010-04-01
Beamforming is a methodology for collection-mode-independent SAR image formation. It is essentially equivalent to backprojection. The authors have in previous papers developed this idea and discussed the advantages and disadvantages of the approach to monostatic SAR image formation vis-à-vis the more standard and time-tested polar formatting algorithm (PFA). In this paper we show that beamforming for bistatic SAR imaging leads again to a very simple image formation algorithm that requires a minimal number of lines of code and that allows the image to be directly formed onto a three-dimensional surface model, thus automatically creating an orthorectified image. The same disadvantage of beamforming applied to monostatic SAR imaging applies to the bistatic case, however, in that the execution time for the beamforming algorithm is quite long compared to that of PFA. Fast versions of beamforming do exist to help alleviate this issue. Results of image reconstructions from phase history data are presented.
Blind Source Separation Algorithms for PSF Subtraction from Direct Imaging
Shapiro, Jacob; Ranganathan, Nikhil; Savransky, Dmitry; Ruffio, Jean-Baptise; Macintosh, Bruce; GPIES Team
2017-01-01
The principal difficulty with detecting planets via direct imaging is that the target signal is similar in magnitude, or fainter, than the noise sources in the image. To compensate for this, several methods exist to subtract the PSF of the host star and other confounding noise sources. One of the most effective methods is Karhunen-Loève Image Processing (KLIP). The core algorithm within KLIP is Principal Component Analysis, which is a member of a class of algorithms called Blind Source Separation (BSS).We examine three other BSS algorithms that may potentially also be used for PSF subtraction: Independent Component Analysis, Stationary Subspace Analysis, and Common Spatial Pattern Filtering. The underlying principles of each of the algorithms is discussed, as well as the processing steps needed to achieve PSF subtraction. The algorithms are examined both as primary PSF subtraction techniques, as well as additional postprocessing steps used with KLIP.These algorithms have been used on data from the Gemini Planet Imager, analyzing images of β Pic b. To build a reference library, both Angular Differential Imaging and Spectral Differential Imaging were used. To compare to KLIP, three major metrics are examined: computation time, signal-to-noise ratio, and astrometric and photometric biases in different image regimes (e.g., speckle-dominated compared to Poisson-noise dominated). Preliminary results indicate that these BSS algorithms improve performance when used as an enhancement for KLIP, and that they can achieve similar SNR when used as the primary method of PSF subtraction.
Cryptanalysis of an information encryption in phase space
Wang, Y.; Quan, C.; Tay, C. J.
2016-10-01
In this paper, we evaluate the security of an information encryption in phase space. We show that the scheme is vulnerable to two kinds of attack, namely, a chosen-ciphertext attack and a known-plaintext attack which is based on an iterative phase-retrieval algorithm using multiple plaintext-ciphertext pairs. The validity of the proposed methods of attack is verified by numerical simulations. The results cast doubts on the present security of information encryption in phase space.
High Fidelity Imaging Algorithm for the Undique Imaging Monte Carlo Simulator
Tremblay Grégoire
2016-01-01
Full Text Available The Undique imaging Monte Carlo simulator (Undique hereafter was developed to reproduce the behavior of 3D imaging devices. This paper describes its high fidelity imaging algorithm.
Pixel Intensity Clustering Algorithm for Multilevel Image Segmentation
Oludayo O. Olugbara
2015-01-01
Full Text Available Image segmentation is an important problem that has received significant attention in the literature. Over the last few decades, a lot of algorithms were developed to solve image segmentation problem; prominent amongst these are the thresholding algorithms. However, the computational time complexity of thresholding exponentially increases with increasing number of desired thresholds. A wealth of alternative algorithms, notably those based on particle swarm optimization and evolutionary metaheuristics, were proposed to tackle the intrinsic challenges of thresholding. In codicil, clustering based algorithms were developed as multidimensional extensions of thresholding. While these algorithms have demonstrated successful results for fewer thresholds, their computational costs for a large number of thresholds are still a limiting factor. We propose a new clustering algorithm based on linear partitioning of the pixel intensity set and between-cluster variance criterion function for multilevel image segmentation. The results of testing the proposed algorithm on real images from Berkeley Segmentation Dataset and Benchmark show that the algorithm is comparable with state-of-the-art multilevel segmentation algorithms and consistently produces high quality results. The attractive properties of the algorithm are its simplicity, generalization to a large number of clusters, and computational cost effectiveness.
An improved dehazing algorithm of aerial high-definition image
Jiang, Wentao; Ji, Ming; Huang, Xiying; Wang, Chao; Yang, Yizhou; Li, Tao; Wang, Jiaoying; Zhang, Ying
2016-01-01
For unmanned aerial vehicle(UAV) images, the sensor can not get high quality images due to fog and haze weather. To solve this problem, An improved dehazing algorithm of aerial high-definition image is proposed. Based on the model of dark channel prior, the new algorithm firstly extracts the edges from crude estimated transmission map and expands the extracted edges. Then according to the expended edges, the algorithm sets a threshold value to divide the crude estimated transmission map into different areas and makes different guided filter on the different areas compute the optimized transmission map. The experimental results demonstrate that the performance of the proposed algorithm is substantially the same as the one based on dark channel prior and guided filter. The average computation time of the new algorithm is around 40% of the one as well as the detection ability of UAV image is improved effectively in fog and haze weather.
The optimal algorithm for Multi-source RS image fusion.
Fu, Wei; Huang, Shui-Guang; Li, Zeng-Shun; Shen, Hao; Li, Jun-Shuai; Wang, Peng-Yuan
2016-01-01
In order to solve the issue which the fusion rules cannot be self-adaptively adjusted by using available fusion methods according to the subsequent processing requirements of Remote Sensing (RS) image, this paper puts forward GSDA (genetic-iterative self-organizing data analysis algorithm) by integrating the merit of genetic arithmetic together with the advantage of iterative self-organizing data analysis algorithm for multi-source RS image fusion. The proposed algorithm considers the wavelet transform of the translation invariance as the model operator, also regards the contrast pyramid conversion as the observed operator. The algorithm then designs the objective function by taking use of the weighted sum of evaluation indices, and optimizes the objective function by employing GSDA so as to get a higher resolution of RS image. As discussed above, the bullet points of the text are summarized as follows.•The contribution proposes the iterative self-organizing data analysis algorithm for multi-source RS image fusion.•This article presents GSDA algorithm for the self-adaptively adjustment of the fusion rules.•This text comes up with the model operator and the observed operator as the fusion scheme of RS image based on GSDA. The proposed algorithm opens up a novel algorithmic pathway for multi-source RS image fusion by means of GSDA.
Polarisation Encryption/Decryption Module
2002-01-01
A polarisation encryption/decryption module comprising at least two array based modulating devices, preferably spatial light modulators (SLMs), at least one array based intensity detector, and at least one source of electromagnetic radiation. A local region of information displayed on a first of ...... rapidly. May be used for real time encryption/decryption of motion pictures. Further, a method of polarisation encrypting and decrypting information. The encryption/decryption is performed optically while the communication is performed electronically....
Efficient iterative image reconstruction algorithm for dedicated breast CT
Antropova, Natalia; Sanchez, Adrian; Reiser, Ingrid S.; Sidky, Emil Y.; Boone, John; Pan, Xiaochuan
2016-03-01
Dedicated breast computed tomography (bCT) is currently being studied as a potential screening method for breast cancer. The X-ray exposure is set low to achieve an average glandular dose comparable to that of mammography, yielding projection data that contains high levels of noise. Iterative image reconstruction (IIR) algorithms may be well-suited for the system since they potentially reduce the effects of noise in the reconstructed images. However, IIR outcomes can be difficult to control since the algorithm parameters do not directly correspond to the image properties. Also, IIR algorithms are computationally demanding and have optimal parameter settings that depend on the size and shape of the breast and positioning of the patient. In this work, we design an efficient IIR algorithm with meaningful parameter specifications and that can be used on a large, diverse sample of bCT cases. The flexibility and efficiency of this method comes from having the final image produced by a linear combination of two separately reconstructed images - one containing gray level information and the other with enhanced high frequency components. Both of the images result from few iterations of separate IIR algorithms. The proposed algorithm depends on two parameters both of which have a well-defined impact on image quality. The algorithm is applied to numerous bCT cases from a dedicated bCT prototype system developed at University of California, Davis.