Index-based permutation-diffusion in multiple-image encryption using DNA sequence

To improve the encryption quality and increase the speed of transmission over the internet, this study aims to provide a fast secure multiple-image encryption (MIE) algorithm based on DNA sequence and image matrix indexes. Because multiple images are considered in the proposed MIE algorithm, one big concern refers to the speed of the algorithm. In the first phase of the proposed method, multiple plain- images are attached together to create a single image. Next, this image is converted to one-dimension array. Half of the array indexes are used to permute all the pixels position. During the permutation, the same indexes are associated with DNA sequence to diffuse the pixels gray level. Simulation results demonstrate that using half of indexes for permutation and diffusion make the proposed algorithm very fast and also using DNA sequence encoding gives the algorithm enough power to resist against common attacks in the era of image encryption.