Abstract
Abstract
In image encryption, the traditional encryption means of scrambling and diffusion are widely used, but they fail to completely eliminate the correlation between the channels of the ciphertext image and still exist security risks. The selecting channel and position scrambling and cross-channel S-shaped diffusion methods proposed in this study push the encryption to a new depth. Compared with ordinary methods, it is more thorough in disrupting pixel positions, increases the complexity of pixel relationships between different channels, and substantially improves the unpredictability of encryption. To support this approach, we design a four-dimensional conservative hyperchaotic system with a very large hyperchaotic interval, which combines the high randomness of the conservative system and the broad key-space property of the hyperchaotic system, effectively defending against the risk of phase-space reconstruction aroused by missing attractors and reducing the possibility of being cracked. We deeply analyze the dynamic properties of the system by means of phase diagrams, bifurcation diagrams and Lyapunov exponents. The cross-channel scrambling and diffusion encryption algorithm designed based on this system not only ensures the security of image information during transmission, but also greatly enhances the ability to resist various attacks. The proposal of this method undoubtedly brings a secure solution to the field of image encryption.