TY - JOUR A2 - Pan, Zhaoqing AU - Gafsi, Mohamed AU - Abbassi, Nessrine AU - Hajjaji, Mohamed Ali AU - Malek, Jihene AU - Mtibaa, Abdellatif PY - 2020 DA - 2020/12/18 TI - Improved Chaos-Based Cryptosystem for Medical Image Encryption and Decryption SP - 6612390 VL - 2020 AB - In the medical sector, the digital image is multimedia data that contain secret information. However, designing an efficient secure cryptosystem to protect the confidential images in sharing is a challenge. In this work, we propose an improved chaos-based cryptosystem to encrypt and decrypt rapidly secret medical images. A complex chaos-based PRNG is suggested to generate a high-quality key that presents high randomness behaviour, high entropy, and high complexity. An improved architecture is proposed to encrypt the secret image that is based on permutation, substitution, and diffusion properties. In the first step, the image’s pixels are randomly permuted through a matrix generated using the PRNG. Next, pixel’s bits are permuted using an internal condition. After that, the pixels are substituted using two different S-boxes with an internal condition. In the final step, the image is diffused by XORing pixels with the key stream generated by the PRNG in order to acquire an encrypted image. R轮加密可以在一个循环中执行increase the complexity. The cryptosystem is evaluated in depth by his application on several medical images with different types, contents, and sizes. The obtained simulation results demonstrate that the system enables high-level security and performance. The information entropy of the encrypted image has achieved an average of 7.9998 which is the most important feature of randomness. The algorithm can take full advantage of parallelism and pipeline execution in hardware implementation to meet real-time requirements. The PRNG was tested by NIST 800-22 test suit, which indicates that it is suitable for secure image encryption. It provides a large key space of 2¹⁹²which resists the brute-force attack. However, the cryptosystem is appropriate for medical image securing. SN - 1058-9244 UR - https://doi.org/10.1155/2020/6612390 DO - 10.1155/2020/6612390 JF - Scientific Programming PB - Hindawi KW - ER -