Image encryption algorithm based on 2D hyper-chaotic system and central dogma of molecular biology

Abstract

Abstract With the widespread use of images, image security has received much attention. Image security can be guaranteed by encrypting the plain image and transmitting the corresponding cipher image. This paper proposes an image encryption algorithm based on the novel two-dimensional (2D) hyper-chaotic system, bidirectional diagonal crossover transformations (BDCTs) and central dogma of molecular biology. Firstly, six chaotic sequences are generated using the proposed hyper-chaotic system, which are used in the permutation and diffusion processes. Secondly, the 5th–8th bit-planes of plain image are permuted using the designed BDCTs. Thirdly, the permuted image is dynamically encoded into a quaternary DNA sequence, and then the quaternary DNA sequence is transcribed into a quaternary RNA sequence. After that, the quaternary RNA sequence is diffused using quaternary RNA operations. Finally, the diffused RNA sequence is translated into a codon sequence, and then the designed codon-level multipoint crossover scheme is used to further improve the diffusion effect. Experiment results and security analyses demonstrate that our algorithm has high security and efficiency. In other words, our algorithm is quite suitable for real-time image cryptosystems.