Multi-channel chaotic encryption algorithm for color image based on DNA coding

There are several issues with existing chaotic encryption schemes for images. These include singularity, unidirectionality, and the complexity of the algorithm. The result is that the encrypted image has low security and acquiring discrete chaotic sequences is time-consuming. In order to solve these problems, a multi-channel chaotic encryption algorithm for color images based on DNA (Deoxyribonucleic acid) coding is proposed. Firstly, a six-dimensional discrete hyperchaotic system is used to generate six sets of chaotic key sequences. Secondly, RGB color components of the color image are extracted. DNA matrices are obtained by DNA coding for each component and merged to construct a combined DNA matrix. After scrambling the DNA matrix, it is split into three same size matrices. The other three matrices are obtained by XOR of the chaotic key matrices. DNA coding is performed for the other three matrices to obtain the corresponding DNA matrices. DNA calculation is performed on two groups of DNA matrices in one-to-one correspondence. The result of DNA calculation is performed by DNA decoding. Finally, multiple round diffusion encryptions are performed on the decoding matrices. Experimental results show that, compared with other methods, the proposed encryption algorithm provides better encryption, can resist different types of attacks, and has higher security. In addition, chaotic sequences can be generated directly by the discrete chaotic system, and the algorithm execution efficiency could be improved.