Color Image Encryption Algorithm Based on DNA Coding and Double Chaos System

This paper combines DNA computing with double-chaos systems and proposes an algorithm for color image encryption at the bit level. First, we use Arnold algorithm to scramble the three components of the color image, and the number of iterations was determined by the average of the three components, which improved the scrambling effect of Arnold algorithm. Secondly, after a lot of experiments, we propose a double-chaos system composed of Lorenz chaotic mapping with variable parameters and fourth-order Rossler hyperchaotic mapping to generate three sets of chaotic sequences for diffusion operation. The double-chaos system compensates the pseudo-randomness of the two types of chaotic mappings, making chaotic sequences more difficult to predict. Then, we transform the chaotic component images and chaotic sequences into DNA sequences in accordance with eight DNA coding rules, and the coding rules are determined by plaintext information or generated chaotic sequences. We also perform addition, subtraction, and XOR operations on them. DNA computation can realize color image bit-level diffusion and reduce the computational cost. The plaintext information is embedded in the encryption process to achieve “One-Time Pad”. Simulation experiments and detailed analysis are conducted with the proposed encryption scheme to prove that the algorithm has good security performance and can effectively resist all types of attacks, indicating that the proposed algorithm is competitive.