2D-ZasHen Chaotic Map-Based Medical Image Cryptographic Approach in IoT-Based Healthcare Monitoring.

The Internet of Things (IoT) is an innovative technology that is revolutionizing the global economy and acquired significant recognition across various sectors, notably within the healthcare field. IoT cameras play a crucial role in facilitating real-time monitoring of the human body through video streams. However, this kind of IoT equipment is vulnerable to various threats. Traditional encryption algorithms such as AES (Advanced Encryption Standard) and RSA (Rivest Shamir Adleman) are commonly used to encrypt textual data. However, they are not suitable for digital image encryption due to computational constraints. Consequently, researchers have proposed cryptographic approaches based on chaotic systems, which offer high speed, security, and low computational costs. In this paper, a new 2D-ZasHen map is proposed, resulting from a combination of two existing 2D maps, along with a new secure chaos-based image encryption approach for IoT healthcare monitoring. The proposed approach involves three significant processes which are key generation, permutation and substitution, inspired by the global existing scheme. Moreover, it considers the confusion and diffusion processes as a single step, executed simultaneously in the same round. This approach effectively meets the requirements of both confusion and diffusion processes, optimizing time efficiency, enhancing security, and ensuring robust encryption and decryption phases. Extensive tests have demonstrated the robustness of the proposed chaos-based approach cryptosystem against differential and entropy attacks, the randomness of the encrypted images, and their sensitivity to slight changes.