基于混沌和边缘特征的医学图像加密算法

摘要

基于混沌和边缘特征,给出一种医学图像加密算法,以改善加密效果并提高安全性能.先对原始医学图像进行位平面分解,并利用混沌序列获得源图像的边缘映射;再对原始图像位平面和源图像边缘映射依次进行异或操作;将异或图像合并后进行像素置乱和像素扩散处理,即可实现对医学图像的有效加密.理论分析和仿真实验表明,所给算法具有较大的密钥空间及密钥敏感性,与已有同类算法相比,其抵抗安全攻击的性能更强.%Based on chaos and edge features ,a medical image encryption algorithm is proposed to improve the encryption effect and the security performance .Firstly ,the bit plane decomposition is carried out against the original medical image to obtain the edge mapping of the source image by using the chaotic sequence . Then , the XOR operation is carried out upon the original image bit plane and the source image edge mapping . Finally , the XOR images are merged together , and their pixels are scrambled and diffused .Thus ,the medical images can be effectively encrypted . Theoretical analysis and simulation results show that the proposed algorithm has larger key space and key sensitivity , and has better performance against the security attacks than the existing similar algorithms .