改进约瑟夫遍历和分段Logistic映射的图像加密算法

为了满足网络通信和图像传输的安全,提出了一种改进约瑟夫遍历和分段Logistic映射的图像加密算法,在置乱过程中通过改进约瑟夫遍历对待加密图像进行全局像素置乱,将置乱像素按照矩阵排列,分解成两个四位的高低矩阵,低四位矩阵利用分段的Logistic混沌映射进行加密处理,对高四位矩阵通过异或运算改变原来矩阵,再将两个四位矩阵结合起来得到加密图像。改进的约瑟夫遍历可以有效抵御周期性攻击,分段Logistic映射引入图像的元素值增强了秘钥的独特性,实验结果证明,该加密算法秘钥空间大,安全性能好,可以抵御穷举,直方图统计等各种攻击。

Image Encryption Algorithm Based on Improved Joseph Traversal and Piecewise Logistic Mapping

In order to meet the security of network communication and image transmission,an image encryption algorithm with improved Joseph traversal and segmented logistic mapping is proposed. In the process of scrambling,the global pixel scrambling of the encrypted image is performed by improving Joseph traversal. The image is decomposed into two four-bit high and low matrices. The low four-bit matrix uses the segmented logistic chaotic map to perform the diffusion operation. The high four-bit matrix is changed to the original matrix by XOR operation,and then the two four-bit matrices are combined to obtain encryption image. The improved Joseph traversal can effectively resist periodic attacks. The segmented logistic mapping introduces the element value of the image to enhance the uniqueness of the key. The experimental results prove that the encryption algorithm has a large key space and good security performance,which can resist various attacks such as exhaustion and histogram statistics.