An improved Bülban map and its application in multiple image encryption

Abstract This article proposes a hybrid satellite image encryption algorithm integrating a modified 1D Bülban chaotic map, a Chinese Go-inspired permutation, and Deoxyribonucleic Acid-based encoding. The Bülban variant adds a sinusoidal perturbation to widen chaotic regions and heighten plaintext and key sensitivity for lightweight, high-entropy key-streams suited to on-board constraints, the Chinese Go permutation utilizes movement and capture logs to remap pixel coordinates in a manner dependent on both the key and plaintext. This effectively breaks the long-range spatial structures typical of satellite imagery, and Deoxyribonucleic Acid encoding supplies per-byte rule variability to strengthen diffusion with low computational cost. Security analysis demonstrates exceptional performance: near-ideal entropy (7. 99 ≈ 7. 99), near-zero pixel correlation, and strong differential resistance with number of pixel change rate and unified average changing intensity values of 99. 5927\% 99. 5927 % and 29. 27038\% 29. 27038 %, respectively. The algorithm also achieves a massive key space of 2^478 2 478, exhibits robustness to occlusion and noise attacks, and allows for lossless decryption (Structural Similarity Index Measure = 1). With an encryption time of 1. 469 seconds for each of the images in a 256 256 256 256 × 256 × 256 pixels image cube, the proposed algorithm balances high security with practical efficiency for satellite imaging pipelines.