A novel image encryption scheme based on hyper chaotic systems and fuzzy cellular automata

摘要

A new image encryption scheme based on hyper chaotic system and Fuzzy Cellular Automata is proposed in this paper. Hyper chaotic system has more complex dynamical characteristics than chaos systems. Hence it becomes a better choice for secure image encryption schemes. Four hyper chaotic systems are used to improve the security and speed of the algorithm in this approach. First, the image is divided into four sub images. Each of these sub images has its own hyper chaotic system. In shuffling phase, Pixels in the two adjacent sub images are selected for changing their positions based upon the generated numbers of their hyper chaotic systems. Five 1D non-uniform Fuzzy Cellular Automata used in encryption phase. Used rule to encrypt a cell is selected based upon cell's right neighbor. By utilization of two different encryption methods for odd and even cells, problem of being limited to recursive rules in rule selecting process in these FCAs is solved. The results of implementing this scheme on some images from USC-SIPI database, shows that our method has high security and advantages such as confusion, diffusion, and is sensitive to small changes in key.