关键词: 图像加密, 级联混沌系统, 混沌迭代, 滤波扩散, 密钥敏感性

Abstract: In response to the problems of the existing chaos system parameter range and the poor diffusion effect of the encrypted algorithm, design a new -class chaos system and filter diffusion model, and propose and implement a color image encryption algorithm with unlimited image size. First, design a new two-dimensional Henon mapping, SINE mapping and Iterative mapping. Pixel location, the other dimension is used to update the filter template and diffusion operation; secondly, in order to avoid the key to reused the key to reduce the security of the algorithm, the "SHA-512" algorithm combines bright text images to generate the key through the calculation of the logo position and weight to generate the key Then, in order to enhance the algorithm diffusion effect, the two -dimensional filter diffusion model is designed. Unlike the traditional filtering diffusion, it changes the image pixel value through fixed templates. ; Finally, complete the encryption. The experimental results show that the pixel change rate and the unified average change intensity can reach 99.6036% and 33.4372% , which is very close to the ideal value. It can resist no noise interference and a 50%tailoring attack with no noise interference with 0.2, and the encryption efficiency is high.

Key words: Image encryption, cascading chaotic systems, chaotic iteration, filter diffusion, key sensitivity