关键词: 信息安全, 图像加密, 遍历矩阵, 像素扩散, 混沌系统

Abstract: In order to improve the randomness and safety of the ergodic matrix and effective protect image information, a new image encryption method was proposed based on the ergodic matrix and pixel value diffusion. First, the input image was permuted independently by using the ergodic matrixes which were generated by discrete chaotic system. And then pixel value diffusion was realized by a uniformly distributed chaotic sequence. The statistical properties of the image got changed and the chaotic mapping was made irreversible; Finally, password generation mechanism was constructed to not only comply with usage of cryptography, but also to enhance usability. A relatively complete encryption system was built up to achieve the image encryption. The security had been analyzed using statistical analysis, key sensitivity analysis, differential analysis, key space analysis, etc. The results demonstrate that the algorithm has good properties of confusion，diffusion and statistic distribution of pixel value, so the algorithm has better scrambling effect in comparison with other approaches. It is safe and practical and easy to realize.

Key words: information security, image encryption, ergodic matrix, diffusion, scrambling chaotic system