A secure and robust image encryption based on chaotic permutation multiple circular shrinking and expanding

In this paper, we propose a secure and robust image encryption based on the chaotic permutation multiple circular shrinking and expanding. An image with the n × m size is encrypted in n set columns and m set rows using the permutation multiple circular and linked bitxor. The proposed method characterized by a very large key space, such that for an image size of 256 × 256, the key space reaches 2⁸⁶²²⁰⁸ which is probably the largest key space ever recorded in a chaotic image encryption. It is sensitive to changes in key, so that the change 1 bit in initial key among 2¹⁶⁸⁴ possibilities is likely to produce a significant different ciphered images (for image peppers NPCR 99:65%, UACI 33.35, r < 0:008). It also resistant to differential attack due to a change 1 bit in the plain image lead to completely different ciphered image (for image lena NPCR 99:60% and UACI 33:47%). The proposed method is also resistant to JPEG compression, noise scheme (Gaussian, Poisson, Salt&Pepper, and speckle), data loss, and brightness-contrast adjustment, so the ciphered image can be stored in smaller file size and transmitted in a noisy communication system.