The Design And Application Of Chaotic System In Digital Image Encrption

With the rapid development of communication networks, Information communication technology has also been greatly improved. Image, as the information carrier, has become the mainstream of communication. Meanwhile, Information security issues are also receiving attention, especially in the digital image transmission, in which the image carrying amount of information, high redundancy often occur leak case In the process of circulation. To ensure information security, researchers have encrypted the information processing. But the traditional encryption technology for digital image encryption can not be guaranteed their safety because of the special nature of the image. How to choose a suitable for image encryption technology is a hot topic in international studies.Chaotic system has to determine the system’s internal randomness of the initial value sensitivity, long-term unpredictability and other characteristics, and it has a natural with cryptograph, which enables the compiler personnel often use chaos theory for image encryption processing. There are many encryption algorithms basing on chaotic, but each has its own advantages and disadvantages. To ensure the security of the encryption algorithm has a higher resistance, people adopt a higher dimension mapping system in the design process and more cumbersome algorithm to image encryption, increasing the difficulty of algorithm. Naturally in the process of deciphering also can resist more attacks. Now Chaotic Encryption technology is still early stages of development, however the advantages of its own must be able to make us gain more breakthroughs about encrypt technology in the future development. This thesis about the research of encryption technology s mainly reflected in the following aspects:1) Introducing the concepts of cryptography and basic theoretical knowledge of chaotic systems, analyzing both features and security evaluation criteria, comparing with their their characteristics, chaotic systems and cryptography has a natural internal relations.2) Introducing several traditional encryption algorithms such as:matrix transformation based image encryption technology, modern cryptography, secret sharing secret image segmentation and encryption technology. Deeply studying the encryption technology which bases on Chaotic system and the principles of encryption configuration, encryption algorithm design, algorithm steps, etc.3)The thesis completed two simulation content. The first one is image encryption algorithm which is based on Logistic map, and made the sensitivity and statistical analysis on the experimental results. The second experiment is based on the three-dimensional map image encryption algorithm of Cat mapping. Before the implementation of the algorithm, we should do the three-dimensional mapping discredited Cat mapping. To improve the security of the algorithm, we use the method of variable control parameters with scrambling-diffusion design principles to achieve the results in the design process, and especially analysis the experiment results.