关键词: 图像加密, Chen’s系统, Logistic映射, 二次加密

Abstract: A new image encryption theme based on dual chaotic systems is proposed. Three-dimensional secret key sequences are generated by combining Chen’s system with Logistic map, and the new encryption sequences are obtained from the three-dimensional secret key sequences by sampling. Then image scrambling algorithm and encryption algorithm are proposed, scrambling algorithm shuffle the positions of the image pixels by using one-dimensional Logistic chaotic sequence, encryption algorithm uses packet encryption and the double encryption to encrypt the value of the pixel. The experimental and theoretical results demonstrate that the algorithm has well properties of confusion and diffusion. The algorithm has strong ability against statistical attacks and enough key space. For the encrypted image the distribution of grey values has a random-like behavior and the adjacent pixels satisfy zero correlation. These results show that the proposed scheme has high security.

Key words: image encryption, Chen’s system, Logistic map, double encryption