一种基于交叉混沌序列的图像加密算法

当前研究的混沌加密算法大都是基于单级混沌系统或低维的混沌加密技术，而这些混沌映射的密钥空间太小，可以轻易地被破译，它们还不算具有严格密码学意义上的保密性。文中提出了一种利用Logistic映射与Chebyshev映射作为2个混沌发生器的算法，在这种交叉混沌映射的图像算法中，不仅通过加密矩阵对图像像素进行灰度置乱，而且根据离散映射生成相应的符号矩阵和置换矩阵。实验结果证明了该算法实现简单，计算量小，且图像的解密结果对混沌序列的初始值有较强的依赖性，安全性高，同时也证明了给出的图像置乱度能更好地反映图像加密前后的视觉差别和加密效果。

An Image Encryption Algorithm Based on Cross Chaotic Sequences

The current chaotic encryption algorithm is based on single level chaotic system or chaotic encryption technique of low dimen sion, and the key space of these chaotic mapping is small which is decoded simply, they ＂also not have strict privacy of cryptography sense. Propose one kind of algorithm based on the Logistic mapping and Chebyshev mapping as two chaotic generators, in the cross chaot ic image encryption algorithm,not only make gray scrambling according to the encryption matrix for image pixel, but also through dis crete mapping generates the corresponding symbol matrix and a permutation matrix. The experimental results show that the algorithm is simple, has a small amount of calculation and image. Decryption of the initial value of the chaos sequence has a strong dependence and high security. It also proves that the image scrambling degree can well reflect the visual difference and encryption effect before and after image encryption.