Multi-Image Encryption Algorithm Based on Novel Spatiotemporal Chaotic System and Fractal Geometry

With the rapid development of communication technology, an increasing amount of image information relies on network transmission. While this enhances transmission efficiency, it also raises the risk of illegal attacks. Therefore, this paper proposes a novel multi-image encryption algorithm based on a new spatiotemporal chaos system and fractal geometry. The algorithm begins by designing a new Chebyshev Improved Coupled Sine Map Lattice (CICSML) system based on the Coupled Map Lattice (CML) spatiotemporal chaos system. Dynamical behavior testing results indicate that, compared to traditional chaos systems, the CICSML system can perform chaotic iterations in both time and space, generating a larger number of chaotic sequences, possessing a broader parameter space, and featuring a wider chaotic region. Secondly, the algorithm uses fractal matrix and Hilbert curve scan scrambling to generate index control sequences for the synchronous scrambling diffusion phase. The initial value sensitivity of fractal matrix and the efficiency of Hilbert curve scan scrambling effectively enhance the security and efficiency of the encryption algorithm. Finally, the algorithm employs the principle of multi-image encryption based on indexed image transformation to encrypt multiple images simultaneously. Experimental simulations and performance analysis results show that the algorithm has good security and strong resistance to attacks.