Image Encryption Algorithm Based on Self-Adaptive Symmetrical-Coupled Toggle Cellular Automata

In this paper, a novel image encryption algorithm, which based on one dimension cellular automata (1 − D,CA), is proposed. Before encryption an original image is separated into two parts. Accordingly, secret key is also divided into two subkeys in order to encrypt the two parts of the image. Corresponding to the two subsections of image, only obtain two parts of cipher text can a receiver decrypt it correctly. The key space of this encryption system not only bases on secret key, which generated by a keystream generator, but also depends on inverse rules of toggle cellular automata. Furthermore, symmetrical-coupled structure of CAs simplifies the cryptosystem's hardware. The proposed image encryption method satisfies the properties of confusion and diffusion due to the wonderful CA substitution. The characteristics of the proposed image encryption system are sharable hardware structure by encryption and decryption, key sharing, self-adaptive inverse rules, very large number of keys and favorable fault tolerance. Simulation results for gray image show that the proposed image encryption method works as out expectations.