Secure image encryption for smart health using cascade logistic map for IoT

The rapid digitization of healthcare has made it essential to secure medical images to preserve patient privacy, stop illegal access, and guarantee data integrity. The emergence of the Internet of Medical Things (IoMT) presents new difficulties because of battery-operated, resource-constrained devices that require strong yet lightweight security. Since chaos-based cryptosystems are inherently unpredictable and sensitive to initial conditions, they have become the most promising method for lightweight encryption. Among them, one-dimensional chaotic maps are especially well suited because of their low computational costs and ease of implementation. However, traditional one-dimensional chaotic maps are susceptible to cryptanalysis because of their drawbacks, which include limited chaotic range, weak randomness, sensitivity to finite precision effects, and predictability. To overcome these drawbacks, we proposed a novel enhanced one-dimensional cascade logistic map (CLM) with better security characteristics, wider chaotic range, sensitivity to initial conditions, unpredictability, and more chaotic behavior. This new map is incorporated into a computationally efficient medical image encryption system made especially for IoMT settings. The encryption process uses a Split-Domain Selective Simultaneous Substitution-Permutation Technique (SSSPT), selectively encrypting the image's first upper half with cipher block and indexing sequences. In addition, the second half is encrypted with the same technique SSSPT using the previously encrypted first half of the image, cipher block, and indexing sequences to obtain the final cipher image. This approach increases the adaptability of the cryptosystem to any minute change. This method preserves computational efficiency while greatly improving resistance to statistical attacks. The suggested system is a workable solution for real-time medical image protection in limited IoMT devices, as experimental findings show that it strikes the ideal balance between security and performance.