Delayed chaotic image encryption algorithm using cross-layer and DNA coding techniques

This work presents a grayscale image encryption algorithm based on delayed chaotic system, and DNA coding with cross-layer techniques, which mainly includes random sequences generation, DNA encoding and decoding, DNA cross-layer confusion operations, pixels cross-layer diffusion. Concrete, firstly, information entropy and the correlation values of original images are combined as the initial value of the delay chaotic system, establishing the relationship between original images and the delayed chaotic system and enhance the relationship between the encrypted images and original images to resist chosen-plaintext and known-plaintext attacks. Secondly, after coding the pixels of images by DNA rules, cross-layer techniques are designed to rearrange the positions of all DNA coding elements using the corresponding the delayed chaotic sequence matrices to achieve confusion effects. Finally, the DNA decoded pixels are divided into four blocks (layers), combining with the state sequences of the delayed chaotic system for cross-layer diffusion operations to complete the final image encryption. The presented image encryption algorithm using cross-layer and DNA coding techniques has considerable advantages compared with the same type of DNA chaotic encryption algorithms, such as key space and sensitivity, information entropy, UPCR and UACI values, efficiency, etc., thus verifying that the delayed chaotic system is conducive to the improvement of information security.