基于改进的CAT置乱与Henon_Kent混沌系统的彩色图像自适应加密算法

为了解决彩色图像加密算法中密钥与明文图像不关联的安全性不足以及CAT映射成立条件的问题，提出一种基于改进的CAT置乱系统与Henon_Kent混沌扩散系统的彩色图像自适应加密算法。该算法首先利用明文图像特征信息生成密钥；然后通过改进的CAT置乱系统对图像进行像素位置的三维置乱，再将Henon_Kent混沌系统所产生的三个混沌序列分别对RGB三个通道的像素灰度值进行扩散；重复以上两个步骤，以密文图像的信息熵大于7.99为结束条件。仿真表明该算法能够抵抗现有的攻击方法，具有较强的加密性能。

Color image adaptive encryption algorithm based on improved CAT scrambling and Henon_Kent chaotic system

In order to solve the problem of the lack of security associated with the key and the plaintext image in the color image encryption algorithm, and conditions for the establishment of CAT maps, this paper proposed a color image adaptive encryption algorithm based on improved CAT scrambling system and Henon_Kent chaotic diffusion system. The algorithm firstly used the feature information of plaintext image to generation key. Secondly, used the improved CAT scrambling system to perform the three-dimensional scrambling of pixel positions; then three chaotic sequences generated by the Henon_Kent chaotic system were used to spread the pixel gray values of the three channels of RGB respectively; repeated the above two steps to ensure that the entropy of the ciphertext image is greater than 7.99. The simulation shows that this algorithm can resist the existing attack methods and has strong encryption performance.