一种新型混沌图像加密算法

针对传统的混沌加密系统因计算机有限精度效应产生的精度退化问题和密钥空间小、安全性能差等缺点，首先利用拓扑共轭基于Logistic混沌导出了另一种混沌映射；然后利用此混沌产生量子Logistic混沌映射的初值，生成置乱用矩阵；再利用两个分段线性混沌映射产生两个扩散用矩阵；采用扩散—置乱—扩散的方法对图像进行加密，大幅度降低了有限精度效应，增强了加密安全性和抗攻击性，有效提高了密钥空间；最后用MATLAB编程，对加密系统进行了各项性能测试；测试结果表明，该加密算法可很好地适用于即时加密的场合.

A novel chaotic image encryption algorithm

In order to solve the shortcomings of the traditional chaotic encryption system due to the precision degradation problem and the small key space as well as poor security performance caused by the finite precision effect of the computer， another chaotic map is designed based on the topological conjugate based on Logistic chaos. Then， the initial values of quantum logistic chaotic maps are generated through the new chaos map so that the scrambling matrices are derived from them. After that， two diffusion matrices are generated by using two piecewise linear chaotic maps. The diffusion-scrambling-diffusion method is used to encrypt the image， which greatly reduces the finite precision and the encryption space is improved. Finally， the performance of the encryption system have tested by MATLAB. The test results show that the encryption algorithm can be applied to the real-time encryption occasion.