A novel color image encryption algorithm based on coarse-grained fractional chaotic system signals is proposed in this paper. First, color images are divided into three channels, which are encrypted based on the corresponding three states of the chaotic system. Second, the chaotic systems are defined as fractional chaotic, in which the fractional order enlarges the parameter space. Third, the fractional chaotic signals are handled with unfixed coarse-grained methods instead of being utilized directly. In addition, the original image and the chaotic signals are divided into bit signals from the pixel values, and the high and low bits are encrypted, respectively. To demonstrate the effectiveness and robustness of the proposed color image encryption algorithm, its properties, including the key space, information entropy, correlation analysis, key sensitivity, and resistance to differential attacks, are provided using a numerical simulation.
相似文献Information security has become a significant issue in encryption due to the rapid progress of internet and network. Therefore, the development of the encryption algorithm is a growing and significant problem. In this study, a new color image encryption was introduced based on DNA complementary rules and pair coupled chaotic maps. At first, the plain color image was divided into three components (R, G, B) being converted into three DNA matrices using DNA encoding rules. Secondly, DNA addition for R, G and B components was implemented and scrambled the elements position of three DNA sequence via the pair coupled chaotic maps. Three gray coded images obtained and RGB encrypted image was achieved by restructuring R, G, B components. The simulation of experimental result and security analysis showed that this algorithm had larger secret key space and strong secret key sensitivity and it had excellent ability to resist against statistical and differential attacks.
相似文献This paper proposes an encryption algorithm that uses the initial values and parameters of the chaotic system as the key, and mainly uses the similar deoxyribonucleic acid (DNA-like) coding method and the similar Zigzag (Zigzag-like) transform to encrypt the image. Firstly, the image is pre-scrambled by the method of Zigzag-like transformation, and then the second scrambling is performed by a sorting scrambling algorithm with identification value. Secondly, the image is diffused by DNA-like coding method. Finally, the image is again diffused using the ortho exclusive OR (XOR) method with chaotic perturbation terms. The experimental results show that the chaotic image encryption algorithm proposed in this paper has satisfactory results. In addition, the algorithm is compared to the previously proposed chaotic image encryption algorithm for the Zigzag transform method or the deoxyribonucleic acid (DNA) coding method. The contribution is to improve the Zigzag transformation method and the DNA coding method, so that it has the advantages of higher security and higher sensitivity. It can also effectively resist exhaustive and differential attacks with better statistical characteristics.
相似文献Based on the deoxyribonucleic acid (DNA) sequence operations and chaotic systems, a novel improved color image encryption algorithm is presented with one-time-pad. Three DNA matrices are obtained by DNA encoding the plain-image firstly. To enhance the proposed algorithm’s robustness of resisting known-plaintext and chosen-plaintext attacks, the key streams, which are used to scramble the positions of the three DNA matrices, are generated from 3D skew tent map (3D-STM) by using the secret keys and the hamming distances between the DNA matrices. Then, we perform the DNA XOR, addition and subtraction operations on the DNA matrices and the key streams to get the cipher-image. At this stage, we also update the initial values of the coupled map lattice (CML) by the circle distance of DNA matrices obtained from the previous step to further enhance the proposed algorithm’s ability of resisting plaintext attack. Finally, we get the encrypted color image by decoding DNA matrices. The simulation and security analysis show that the proposed algorithm has an extraordinary ability to resist plaintext attack, differential attack and statistical attack, etc.
相似文献In present digital era, multimedia like images, text, documents and videos plays a vital role, therefore due to increase in usage of digital data; there comes high demand of security. Encryption is a technique used to secure and protect the images from unfair means. In cryptography, chaotic maps play an important role in forming strong and effective encryption algorithm. In this paper 3D chaotic logistic map with DNA encoding is used for confusion and diffusion of image pixels. Additionally, three symmetric keys are used to initialize 3D chaos logistic map, which makes the encryption algorithm strong. The symmetric keys used are 32 bit ASCII key, Chebyshev chaotic key and prime key. The algorithm first applies 3D non-linear logistic chaotic map with three symmetric keys in order to generate initial conditions. These conditions are then used in image row and column permutation to create randomness in pixels. The third chaotic sequence generated by 3D map is used to generate key image. Diffusion of these random pixels are done using DNA encoding; further XOR logical operation is applied between DNA encoded input image and key image. Analysis parameters like NPCR, UACI, entropy, histogram, chi-square test and correlation are calculated for proposed algorithm and also compared with different existing encryption methods.
相似文献In this paper, we propose a novel medical image encryption algorithm based on a hybrid model of deoxyribonucleic acid (DNA) masking, a Secure Hash Algorithm SHA-2 and a new hybrid chaotic map. Our study uses DNA sequences and operations and the chaotic hybrid map to strengthen the cryptosystem. The significant advantages of this approach consist in improving the information entropy which is the most important feature of randomness, resisting against various typical attacks and getting good experimental results. The theoretical analysis and experimental results show that the algorithm improves the encoding efficiency, enhances the security of the ciphertext, has a large key space and a high key sensitivity, and is able to resist against the statistical and exhaustive attacks.
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