Medical image region of interest encryption combined with discrete wavelet transform and hyperchaotic system
Xiaodong Chen, Xiaoqiang Di, Jinqing Li, Jianping Zhao, Xiaojie Liu · 2019
In order to better suit the continuous development of medical environment and protect the medical image security, a novel region of interest (ROI) of medical image encryption scheme based on two-dimension discrete wavelet transform (2-D DWT) and five-dimension hyperchaotic system is proposed. In this paper, the medical image is first separated into ROI and background area, and one low frequency and three high frequency components in the horizontal(H), vertical(V) and diagonal(D) directions of ROI are obtained via 2-D DWT. Next, only the low frequency component which approximate the original image is scrambled and spread by chaotic sequence. Then, the reconstruction ROI of image is generated by using encrypted low frequency and components of H, V and D. Fin1 ally, the confusion-diffusion process is used to encrypt the reconstruction ROI of image. Our scheme can realize the encryption of medical image not only in space domain but also in frequency domain. Experiments simulation results, such as key sensitivity tests, correlation analysis, information entropy tests, known/chosen plaintext attack analysis and comparison tests, show the advantages of our scheme.