Application And Research Of Chaotic Theory In Image Encryption

In recent years, with the development of computer technology and networktechnology, multimedia information has been widely applied to various fields ofsociety. Digital image is an important carrier of multimedia information, it hasvivid, intuitive, image, and many other features. Therefore, the digital image iswidely spread in the network and become one of the main methods of informationexpress today. Digital image communication bring convenience to people,however, at the same time, also there are many potential safety hazard. Thedigital image security problem becomes a hotspot of academia and industry.Chaotic systems have many good qualities like extreme sensitivity to initialvalues and ergodicity, pseudo random, and can reproduce, and generate chaossequence is very fast. Therefore, chaotic theory in image encryption has become adigital image encryption a hot spot of research direction. Compared with thetraditional image encryption algorithm, image encryption algorithm based onchaotic system has a unique advantage in the processing of large amounts of data,to reduce the image redundancy information. Therefore, the image encryptionbased on chaotic system has been widely studied.This article adopts the method of combining algorithm design andsimulation, using chaotic systems with the combination of image scramblingalgorithm, designed efficient security of digital image password system. Thisarticle verify the password security of the system from the key space, keysensitivity, histogram, correlation between adjacent pixels and differentialattacks.First of all, this article proposed an improved scrambling algorithm based onthe Arnold scrambling algorithm. This algorithm combined with one-dimensionalchaotic Logistic system randomly selected pixel scrambling. Make up for thedisadvantages of the Arnold algorithm can only be applied to square image, and makes the scrambling speed improve greatly, can achieve a scrambling toscrambling requirements, to ensure the real-time performance of the encryptionalgorithm.Secondly, this article proposed an color image encryption algorithm basedon one-dimensional chaotic Logistic system and three dimensional chaoticLorenz system. First of all, according to the improvement of plaintext imagescrambling algorithm pixel scrambling, scrambling for the chaotic image, thenthe random sequence produced by chaos system of three component of colorimage RGB pixel values for mixed encryption, and spread to the way, increasethe complexity of the encryption. Safety analysis show that the algorithm hasgood encryption effect and high safety.Finally, this paper proposed an image encryption algorithm based onimproved image scrambling algorithm and hyperchaos system. Using four chaoticsequence generated by the chaos system, after processing, select a processingsequence, based on the improved scrambling algorithm with its scrambling pixellocation. Then use the other three processed chaotic sequence, complete for thespread of the pixel values of encryption. Safety analysis show that the algorithmcompared with the previous algorithm achieve a higher security.