SMLIE: a SHA-512 seeded multi-layer image encryption algorithm for medical image security

Protection of medical images during transmission and storage is critical for ensuring patient confidentiality. To provide secure encryption for healthcare applications, this study proposes the SHA-512 Seeded Multi-Layer Image Encryption (SMLIE) algorithm. It generates a session-specific key by hashing a password and the timestamp of the system using SHA-512, from which the initial states and parameters of the chaotic maps are deterministically derived for reproducibility. The encryption procedure consists of seven layers: Arnold scrambling, logistic map XOR, SHA256 masking, adaptive salt injection, row-column permutation, DWT embedding, and Henon map-based XOR, all of which improve diffusion, entropy, and adaptability to various attacks. A MATLAB graphical user interface (GUI) is used to visualize the encrypted pixel data during validation. The experimental findings indicate a high level of entropy, NPCR, and UACI, demonstrating the effectiveness of the algorithm for encrypting medical images in real time, especially in resource-constrained environments. SMLIE is suitable for real-time healthcare systems in which both privacy and low latency are essential.