A novel color image encryption algorithm based on infinite collapse map and hierarchical strategy

Abstract

Chaos-based image encryption algorithms are important for information security, but current chaotic systems and encryption algorithms still have optimization potential. This paper proposes a novel one-dimensional improved composite chaotic map (1D-ICCM) to enhance chaos performance and the efficiency of generating chaotic sequences. The dynamic characteristics of the 1D-ICCM are analyzed in depth, demonstrating favorable chaotic properties. Based on this, we introduce a hierarchical strategy image encryption algorithm (HS-IEA) that combines 1D-ICCM and the Logistic map to improve the robustness and security of image encryption algorithms. The algorithm begins by integrating the image at the pixel level and performing secondary diffusion on the integrated sequence. After restoring the color channel matrices, the image is encrypted at the pixel level using bidirectional dynamic scrambling. Then, bit-plane decomposition is applied. To handle large amounts of data at the bit level, high-order and low-order bit planes are processed separately: high-order planes are encrypted using bit-level diffusion, while low-order planes use bit-plane rotation. Finally, the encrypted bit-planes and color channel matrices are merged for two-layer encryption. Experimental results and security evaluations confirm that the HS-IEA significantly improves image encryption's robustness, security, and performance.