Image encryption technique with key diffused by coupled map lattice

This paper deals with a problem of key diffusion in chaotic image encryption algorithms. Usually, these approaches use multiple pseudo-random sequences for operations done during encryption and decryption. As each of these sequences is generated by part of selected key, in case that only small portion of key is changed, some of sequences could remain the same. This problem is solved by usage of Coupled Map Lattice which introduces dependencies between chaotic maps used for generation of the pseudo-random sequences. Paper also mentions other approaches, and compares their results with those achieved by the proposed algorithm by means of commonly used measures. The main advantages of our proposal include high values of entropy and Unified Average Changing Intensity.