An image encryption algorithm based on joint RNA-level permutation and substitution

Duzhong Zhang, Xiancheng Wen, Chao Yan, Taiyong Li

Abstract: Permutation and substitution are two essential operations in image encryption. Classical image encryption algorithms usually apply these two operations separately in “permutation-substitution” scheme, i.e., first permutation then substitution, or first substitution then permutation. It has been reported that image algorithms using such scheme are of high risks because attackers may crack the two processes separately. To solve this problem, a novel joint RNA-level permutation and substitution (JRPS) based image encryption algorithm is presented in this paper. By employing a six-dimensional (6D) hyper-chaotic system to generate pseudo-random sequences, the proposed algorithm has sufficiently complex behaviors for encryption. And plaintext image is changed to RNA codon sequence according to RNA rules. Running the joint RNA-level permutation and substitution two rounds on this RNA codon sequence, a cipher image could be obtained. The simulations reveal that the proposed algorithm could withstand various attacks.