Enhanced Arnold’s Cat Map-AES Encryption Technique for Medical Images

Human’s health information is considered momentous information, which is represented in medical systems. The amount of medical image information available for analysis is increasing with the modern medical image devices and biomedical image processing techniques. To prevent data modification from unauthorized persons from an insecure network, medical images should be encrypted efficiently. In this paper, a novel chaotic-based medical image encryption technique is proposed. This technique uses first a Butterworth High Pass Filter (BHPF) to enhance the medical image’s details to avoid any possible loss of medical details during the encryption-decryption process. The proposed technique is then developed by modifying Arnold’s cat map technique combined with the well-known Advanced Encryption Standard (AES) algorithm. By modifying Arnold’s cat map technique, three bits are formulated and added to the regular AES encryption key to increase the overall encryption robustness. A comparative study is conducted to compare first the efficiency of the proposed technique concerning Arnold’s Cat Map with AES (Cat-AES) and AES in its standard form. Then, the proposed encryption technique is also compared to the state-of-the-art chaotic-based medical image encryption techniques. It is shown from the comparative study that the proposed approach is capable of increasing both the strength of the encryption/decryption process and the quality of medical images with a reduction of the overall computational cost.