A novel image encryption algorithm based on the Rubik’s cube scrambling is proposed in this paper to achieve simultaneous encryption of a group of images. This proposed encryption algorithm begins with chaotic Baker map permutation with a selected mode of operation or RC6 algorithm as a first step for encrypting the images, separately. After that, the obtained encrypted images are further encrypted in a second stage with Rubik’s cube. Chaotic or RC6 encrypted images are used as the faces of the Rubik’s cube. From the concepts of image encryption, the RC6 algorithm adds a degree of diffusion, while chaotic Baker map adds a degree of permutation. The Rubik’s cube algorithm adds more permutation to the encrypted images, simultaneously. The simulation results demonstrate that the proposed encryption algorithm is efficient, and it exhibits strong robustness and security. The encrypted images are further transmitted over a wireless channel with Orthogonal Frequency Division Multiplexing (OFDM) system, and decrypted at the receiver side. Evaluation of the quality of the decrypted images at the receiver side reveals good performance.
相似文献An efficient and simple encryption and compression scheme for digital image is reported in this paper. This scheme is based on the algorithm of the generalized knight’s tour, discrete cosine transform and non-linear chaotic maps. In this scheme, according to the structure of compression, confusion and diffusion are attained by methods of the generalized knight’s tour and chaotic maps. Firstly, the generalized knight’s tour algorithm is utilized to scramble the pixels while the data correlation preserved. Then, the chaotic system is used to generate a pseudorandom permutation to encrypt the part of coefficients from discrete cosine transform for diffusion. Experimental results show that the proposed scheme can gain robust security and a high compression ratio, which indicates that the proposed scheme is practicable.
相似文献In the era of big data, many fields produce massive images every day. To improve the security of image transmission, a multiple-image encryption algorithm based on bit planes and chaos is proposed. Firstly, k images are decomposed into 8k bit planes; secondly, the Chen chaotic system and two-dimensional Logistic map are used to scramble pixel positions of the 5th-8th bit planes of each image; thirdly, the scrambled bit planes and all the 1st-4th bit planes are randomly combined into k scrambled images; finally, to obtain k encrypted images, the exclusive OR operation is performed on the chaotic image and k scrambled images. Experimental results and algorithm analyses show that the proposed algorithm has the advantages of the excellent encryption effect, high encryption efficiency, large key space, key sensitivity, strong ability to resist the statistical attack, the brute-force attack, etc.
相似文献In order to study the application of chaos in video image encryption, a real-time video secure communication system based on a new grid multi-wing chaotic system is proposed in this paper. First, by introducing sawtooth wave functions to the Lorenz system, a new grid multi-wing butterfly chaotic system with complicated dynamical behaviors is obtained. Compared with the existing multi-scroll and multi-wing chaotic systems, The system structure is simple and more easier to be implemented in a digital system. Then, a chaos-based pseudorandom random number generator is developed by implementing post-processing procedure. The present video secure communication system is designed with the closed-loop feedback scheme. The corresponding hardware implementation is developed by FPGA platforms, and the experimental results are given to verify its feasibility. Furthermore, a series of widely used secure analyses are applied to prove that the system has good security performance.
相似文献In this paper, a new scheme for image encryption based on a double chaotic pseudo random generator (DCPG), simple XOR and shift rotations operations is proposed. The DCPG is a combination of both Tent and Chebyshev chaotic and so it needs three values of control parameters which are used as shared secret keys. The encryption consists of two rounds. In the first round, the hash value of the input image is computed using SHA-512. This value also is used as a forth shared secret key and from which, 4 amounts of the shift rotations are extracted. A pseudorandom sequence is generated using the proposed DCPG with the same size of the input image. This sequence and also the input image are divided into blocks of size 1?×?8. Each block of input image is processed with the corresponding block of the pseudorandom sequence using simple shift rotation and XOR operation. To extend the effect of the original image one pixel change to all the pixels of the cipher image, a second round of XOR operation is added. The proposed scheme has many advantages. It is highly secure due to two reasons. Firstly, it uses four secret keys for encryption which provides a large key space to overcome all types of brute force attacks. Secondly, the amounts of shift rotation used are input image dependent which achieves a strong resistance against chosen plaintext attacks. Also, it is more efficient compared to other recently existing schemes as it consists only of two rounds of simple operations. Security analysis of scheme has been provided. Based on the results, our scheme is highly secure with a reduced encryption time and so it can be used for many applications which require real time secure image communications.
相似文献In recent years, various chaos-based image encryption algorithms have been proposed to meet the growing demand for real-time secure image transmission. However, chaotic system that is the core component of chaos-based cryptosystem usually degrades under finite computing precision, causing many security issues. In this paper, a novel cryptosystem with analog-digital hybrid chaotic model is proposed. Firstly, the analog Chen chaotic system and the digital Logistic map are adopted to depict the capability of the hybrid model, in which analog system is used to perturb digital system. Dynamic analyses demonstrate that the hybrid method has better complexity, larger chaotic parameter range and good ability to counteract dynamical degradation. The chaos-based key streams generated by the perturbed Logistic map are more suitable for image encryption. Secondly, a parameter selection mechanism is introduced to increase security. The state variables of Chen chaotic system and cipher image are involved in parameter selection process to dynamically change the parameter of the perturbed Logistic map. The involvement of cipher image makes the key streams relevant to plain image and can resist known/chosen-plaintext attacks. Performance, security and comparison analyses indicate that this cryptosystem has high security, low time complexity, and ability to resist common attacks.
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A novel bit-level image cryptosystem is proposed by introducing a new coupled map lattices (CML). The modified non-adjacent spatiotemporal chaotic system with good dynamic performance is constructed by coupling the piecewise-linear chaotic map (PWLCM) in a non-adjacent manner. In the proposed bit-level image cryptosystem, the binary plain image is scrambled globally by a 2D hyper-chaos system. And the confused image is then diffused via the pseudo-random sequences produced quickly and efficiently from the fabricative CML. After converting the diffused binary matrix into its homologous decimal matrix, the cipher image is achieved. Computer simulations and performance comparisons with recent image encryption algorithms demonstrate the superior performance and high security of our proposed cryptosystem.
相似文献This paper presents a novel color image encryption approach. The proposed approach utilizes the basic concepts of DNA cryptography along with Lorenz and Rossler chaotic system and 2D logistic map. The proposed approach encrypts RGB images using DNA cryptography techniques. In diffusion phase, at pixel level Lorenz and Rossler chaotic system is used to encrypt the three channels of test images. Afterwards, at bit level 2D logistic map is used for performing bitwise chaotic ponytail process on these diffused Red, Green, and Blue channels in confusion phase. Simulation of the proposed approach on test images reveals that the color images have been encrypted very efficiently.
相似文献In a finite precision computing environment, the trajectories of all chaotic sequences enter a cycle leading to degradation of their dynamics. In this paper a new perturbation feedback hybrid control method to reduce the influence of finite precision. A traditional logistic map is introduced as a pseudo-random sequence generator for time-varying perturbation to perturb the coefficients of chaotic map and make them iteratively changed in the chaotic region. The nonlinear feedback mechanism has high complexity. Numerical analysis results show that the perturbation-feedback hybrid control method can effectively attenuate the dynamic degradation of digital chaotic systems. Further, we propose a simple encryption algorithm based on the perturbation-feedback hybrid control method and apply it to image encryption. The NPCR and UACI of our encryption method are 0.99609 and 0.33464, respectively and the information entropy is as high as 7.9976. All the numerical experiments results prove that the proposed algorithm is highly secure, resistant to multiple attacks, and is more competitive than other encryption algorithms.
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