基于混沌和伽罗瓦域运算的新型彩色图像加密算法  

A Novel Color Image Encryption Algorithm Based on Chaos and Galois Field Operation

作　　者：叶瑞松[1] 兰欢 YE Ruisong;LAN Huan(Collage of Science,Shantou University,Shantou515063,China)

机构地区：[1]汕头大学理学院

出　　处：《徐州工程学院学报（自然科学版）》2019年第4期8-17,共10页Journal of Xuzhou Institute of Technology(Natural Sciences Edition)

基　　金：国家自然科学基金项目（11771265）

摘　　要：提出一个基于混沌和伽罗瓦域运算的新型彩色图像加密算法.该算法采用伽罗瓦域上扩散与置乱相嵌-颜色通道间置乱-双向扩散的加密结构,对长宽一致的彩色明文图像进行加密.在伽罗瓦域上的加密操作阶段,对图像进行颜色通道分离,利用SHA-512算法和提出的改进Logistic映射生成3个可逆矩阵,在伽罗瓦域上将各颜色通道矩阵与可逆矩阵进行复杂矩阵乘法运算,中间相嵌3次置乱运算.在置乱阶段,利用置乱序列将颜色通道位置进行搅乱.在扩散阶段,利用改进Logistic映射生成混沌序列对图像进行正向和逆向的扩散操作,进一步提高算法的安全性.安全性能分析结果表明该算法具有极大的密钥空间、良好的统计特性、极强的密钥敏感性、明文敏感性,可有效抵抗多种攻击.A novel color image encryption algorithm based on chaos and the operations on Galois field is proposed.The algorithm uses the encryption structure:embedded diffusion and scrambling on Galois field-scrambling of color channels-bi-directional diffusion to encrypt color plaintext images with consistent length and width.At the encryption operation phase on Galois field,plaintext images are separated into three color channels,and three invertible matrices are generated by using the SHA-512 algorithm and the proposed improved Logistic map;complex matrix multiplication operations are then performed between color channel matrices and invertible matrices on Galois field,and three scrambling operations are embedded in the above phase.At the scrambling phase,the position of the color channels is disturbed by using the scrambling sequence.At the diffusion stage,the chaotic sequence generated by improved Logistic mapping is used to carry out forward and reverse diffusion operations on the image,which further improves the security of the algorithm.The results of security performance analysis show that the algorithm has great key space,good statistical characteristics,strong key sensitivity,plaintext sensitivity,and ciphertext sensitivity,and can effectively resist multiple attacks.

关 键 词：图像加密 混沌系统 伽罗瓦域运算 置乱 LOGISTIC映射 

分 类 号：TP309.7[自动化与计算机技术—计算机系统结构]