A Dynamic Triple-Image Encryption Scheme Based on Chaos, S-Box and Image Compressing

To guarantee the security and high-efficiency of image transmission, a novel triple-image encryption scheme based on chaotic system, S-box and image compressing is proposed in this paper. Firstly, the combination process is performed by compressing three plain images to 25% and combining the compressed images with a stochastic matrix generated by the 2D-LSCM system to construct a new image. This process makes the proposed image encryption scheme have higher image transmission efficiency comparing to that of the state-of-the-art methods. Then, Z-scan and the proposed coded lock scrambling algorithm with low time complexity is used to randomly scramble the positions of pixels in the new construct image. Next, a cipher image is obtained by performing the diffusion operation on the scrambled image through S-box and chaotic sequences. In addition, the added stochastic matrix in the combination process makes the cipher image dynamic. In other words, the generated cipher images are always different to each other even when they are generated by the proposed encrypt scheme with identical plain images under the same secret keys, which can resist chosen-plaintext attacks. Finally, experimental results and simulation analysis are performed, which shows the proposed scheme can effectively resist common kinds of attacks.