Cryptanalysis and Improvement of Chaos‐Based Image Encryption Scheme with Circular Inter‐Intra‐Pixels Bit‐Level Permutation
Haiju Fan, Ming Li · Mathematical Problems in Engineering · 2017
A novel chaos‐based image encryption scheme has been proposed recently. In this scheme, redundancies of the Fridrich’s structure were reduced significantly via a new circular inter‐intra‐pixels bit‐level permutation strategy. However, we proved that the original encryption scheme is vulnerable to the known/chosen‐plaintext attacks. Both the permutation and diffusion phases have been improved to enhance the security of the original scheme. By shifting each row of the plain image randomly, known‐plaintext attacks could be resisted. Furthermore, by appending double crossover diffusion to the end of the original scheme, chosen‐plaintext attacks lost their efficacies. Simulation results demonstrated that the improved encryption scheme outperforms the original one.