Hybrid image encryption using multi-chaos-system

As a result of the development of computer network technology, communication of information through personal computer is becoming more convenient. Meanwhile, it also gives hackers opportunities to attack the network. Therefore the communication security is now an important issue for multimedia communications. This paper proposed a hybrid encryption technique for the color image based on the multi-chaotic-system which combines Pixel-Chaotic-Shuffle (PCS) and Bit-Chaotic-Rearrangement (BCR). The idea of applying chaos theory on image encryption is because of the behavior of chaos system exhibiting nonlinear dynamics and sensitivity to initial conditions. Therefore, the distinguished elements of variables applied to produce encryption codes for the color-image encryption can increase the communication security. In this paper, the pixels of plain image are firstly disarrayed by PCS, and then their bits are rearranged using BCR. This method increases the key space of images, completely eradicates the outlines of the encrypted images, blurs the distribution characteristics of RGB-level matrices, and effectively protects against the decryption of exhaustive attack method. The test methods involving key space and correlation coefficient r are adopted for the security analysis. Eventually, empirical images are adopted as examples to prove the great encryption performance of the proposed method and also the good potential for practical applications in image encryption.