Chaotic Image Encryption Algorithm Based On The Cat Map And Logistic Map

Chaos is a special form of exercise in a non-linear system with extreme sensitivity to initial condition. Therefore, a small number of parameters in initial state can produce chaotic cipher sequence to meet the basic characteristics of modern cryptography. In addition, chaos is of the inherent randomness, noise-like, long-term unpredictable characteristics. Aliasing features of chaos almost meet requirements of the encryption system naturally. Chaotic image encryption technology is the use of discretized chaotic sequence to encrypt image. Its essence is to play to the characteristics of chaos to cover up the original appearance of the image, to let others cannot obtain valuable information even if they received encrypted information, but the decrypting part can decrypt the image with pre-agreed encryption algorithm and key. Chaotic system features make it not a numerically stable probability distribution, and its number set is in the real field. In theory, with the help of chaotic systems for image data encryption, you can prevent an exhaustive cryptanalyst attack method, frequency analysis attacks, and improve the security of the encryption system. As a brand-new development direction of image encryption, chaotic image encryption technology has good application prospects.In this paper, the main content is:1. A brief introduction on the development of chaotic history, the background and significance of the research. And then describes the current development of the chaotic image encryption.2. Detailed description of the chaos theory, including the definition of chaos, chaos criterion, chaotic motion characteristics. Explain the basics of cryptography, including basic concepts of modern cryptography and cryptology, classification of cryptology. Focus on the security features of cryptanalysis and encryption algorithm. A brief description of the relationship between chaos theory and cryptography, providing theoretical support for later discussion.3. Described the basics related to image, including the concept of the image, the common format of image, the structure of the image. Grayscale histogram, etc. And then explained image features and its the relationship with the encryption algorithm; then described a chaotic image encryption algorithm and focused on the strengths and weaknesses for the of two principles the chaotic image encryption algorithm scrambling and diffusion.4. Described the simulation of two chaotic maps, that is, cat map and logistic map, and made a detailed description and MATLAB simulation of this dual chaotic encryption algorithm based on the cat map and Logistic map. Explained key space analysis, spatial analysis, correlation analysis of encryption result. Come to a conclusion that the algorithm is of good encryption/decryption effect.