Cryptography based on Spatiotemporal Chaos System and Multiple Maps

In this paper, a stream image cryptography has been proposed based on spatiotemporal chaos system. It is specifically designed for the colored images, which are 3D arrays of data streams. One-way coupled map lattices (OCML) are used to generate pseudorandom sequences and then encrypt image pixels one by one. By iterating randomly chosen chaotic maps from a set of chaotic maps for certain times, the generated pseudorandom sequences obtain high initial-value sensitivity and good randomness. The initial conditions of chaotic maps and parameters of the algorithm are generated by a 128-bit external key. The results of several experimental, statistical analyses and key sensitivity tests prove the security robustness of the proposed cryptosystem.