A secure medical image encryption algorithm for IoMT using a Quadratic-Sine chaotic map and pseudo-parallel confusion-diffusion mechanism

Medical image transmissions within the Internet of Medical Things (IoMT) present critical security and privacy challenges, necessitating efficient and robust encryption solutions. This paper introduces a novel 1D Quadratic- Sine (1DQS) chaotic map, designed to achieve a balance between rapid implementation and enhanced chaotic properties, and its application in a medical image encryption scheme (1DQS-IE). The proposed scheme dynamically updates the secret key using plain image data to reduce predictability and employs a block- based pseudo-parallel confusion and diffusion algorithm for fast execution. Simulation results confirm the 1DQS-IE's capability to generate random-like encrypted images with uniform pixel distributions in real-time. Security and comparative analyses highlight its effectiveness in breaking pixel redundancy, ensuring high randomness, supporting large, sensitive secret keys, recovering damaged images, and defending against brute- force, statistical, and differential attacks. These findings validate the 1DQS-IE's suitability for secure IoMT applications.