A Watermarked Image Encryption Scheme Based on Hyperchaotic Map and Lorentz Force Shift for Medical IoT Applications

To increase the confidentiality of medical images and the accuracy of post-event responsibility determination in the Medical Internet of Things, this paper proposes an effective medical watermarked image encryption scheme. First, the watermark is embedded into the medical image through the DWT algorithm, and then a Memristor Modulation Hyperchaotic Map (3D-MMHM) is constructed. The scheme utilizes the pseudorandom sequence it generates to perform Lorentz force shift permutation and diffusion on the medical image embedded with the watermark to obtain the cipher. Finally, comprehensive experimental performance evaluations all approach the theoretical values. After being attacked, the cipher can still be decrypted to recover most parts of the image, and the watermark can also be extracted, fully demonstrating that this scheme has extremely strong robustness and anti-attack ability. It is of great significance in terms of the confidentiality of medical images and the accountability after the attack and decryption processes.