基于迷宫置换和Logistic混沌映射的图像加密算法

传统基于置换和混淆的图像加密算法，置换效率低且难以抵抗已知/选择明文攻击，针对此问题，提出基于迷宫置换和Logistic映射的图像加密算法。为提高置换效率，采用深度优先搜索(DFS)迷宫生成算法来高效产生置换；为抵抗已知/选择明文攻击，将待加密图像的消息摘要算法5(MD5)摘要与用户密钥绑定,用以产生迷宫起点坐标、Logistic参数和初值，然后由Logistic映射产生随机数，来决定迷宫置换的节点试探方向和参与混淆，从而使加密环节与明文图像紧密相连。实验表明，所提算法具有较好的加密质量、较高的安全性，且能抵抗已知/选择明文攻击。

Image encryption algorithm based on maze permutation and Logistic chaotic map

In conventional permutation and confusion based image encryption algorithm, there usually exists some problems such as inefficient permutation and difficult to resist known or chosen plaintext attack. To solve these problems, an image encryption algorithm based on maze permutation and Logistic mapping was proposed, where Depth First Search (DFS) maze permutation was used to product permutation efficiently. In order to resist known or chosen plaintext attack, the plaintext image Message Digest Algorithm 5 (MD5) digest was bound with the user key to generate maze starting coordinates, Logistic chaotic map parameters and initial values which drive Logistic maps to generate random numbers. These random numbers were used to determine maze node probing directions and participate in image confusion to make all encryption stages tight coupled with the plaintext image. Experiments show the proposed algorithm has better performance in encryption quality and it can resist known or chosen plaintext attack with high security.