Improvement of chaotic secure communication scheme based on steganographic method and multimodal dynamic maps

In this paper a novel picture steganographic method using multimodal chaotic maps for improvement of chaotic secure communication is presented. Stego image is sent by modulating parameters of the transmitter. The presented method includes a receiver system for asymptotic convergence which estimates uncertain parameters of Rossler system. The gain of the receiver system changes continuously by a high order sliding mode adaptive controller (HOSMAC), so that system output errors converges to zero. The converged parameters are used to determine the family of maps. After deciding map set, grey level modification for hiding the message is selected and the stego image is produced. Using the synchronisation and chaotic modulation method, the proposed method is studied in the field of secure communications.