A wheel-switch chaotic system for image encryption

Because of high sensitivity for initial values and random-like behaviors, chaotic systems are widely used in image encryption. Conventionally, encryption keys for these image encryption methods based chaotic systems are limited to manipulate the initial values or parameters of the chaotic system. However, effective attacks are found to crack encryption systems by using prior information about the system chaotic map. In this paper, we introduce a wheel-switch chaotic system for image encryption. The used chaotic map is not fixed but changeable via the wheel-switch structure according to the controlling sequence. Further, a substitution and permutation network based image encryption algorithm using the wheel-switch chaotic system is also provided. Experimental results showed that the proposed system with the key schedule inherits the random-like property of single chaotic system with additional security level from the wheel-switch structure. The same idea is also applicable to secure communication, and data encryption for other multimedia.