High sensitivity image encryption algorithm based on cascaded chaotic system

Chaotic systems are widely used in cryptography due to their complexity and unpredictability. This paper proposes a novel power exponential chaotic system (PECS), which gives the system better cryptographic properties than the classical and newest ones through the experimental results shown. Furthermore, the systems are applied to a new encryption method to improve the security and robustness of image communication. First, the initial parameters and key stream are perturbed by plaintext information. Then, block the plaintext image with a modified chaotic sequence and carry out the dynamic diffusion on the scrambled pixels to obtain the encrypted image. Among them, one of the interference values in diffusion is the dynamic ciphertext pixel selected by the previous diffusion pixel and chaos interference value. Both the scrambling and diffusion phases incorporate interference from the plaintext and intermediate ciphertext pixels. Therefore, the proposed algorithm has high plaintext information sensitivity to better defend chosen-plaintext attacks. Experimental analysis shows that the metrics such as Entropy (IE), Unified Average Changing Intensity (UACI), Shannon entropy et al. of our algorithm are all close to ideal results, demonstrating its ability to resist cryptographic attacks.