基于混沌系统的彩色图像加密算法

为提高图像加密算法的安全性,提出一种将改进的Lorenz混沌系统应用到彩色图像的加密方案,同时考虑RGB三分量之间的相互关联。提取彩色图像的RGB三分量并分块,将混沌系统产生的伪随机序列转换为明文相关的密钥序列和动态置乱序列,明文发生微小改变密钥流序列也会完全不同;对R分量实现块置乱和像素点逐一置乱,对G、B分量分别进行迭代扩散;对已加密的三分量进行前向和后向扩散。仿真和安全性分析结果表明,该算法具有可行性、较高的安全性和密钥敏感性。

Color image encryption algorithm based on chaotic system

To improve the security of image encryption algorithm,the improved Lorenz chaotic system was applied to the encryption scheme of color image,and the correlation among the RGB three components was also established. The RGB three components of color image were extracted and partitioned. The pseudo-random sequences generated through the chaotic system were converted into plaintext-related key sequences and dynamic scrambling sequences. If a tiny change happens in plaintext,key stream sequence will be completely different. The dynamic scrambling sequences were used in the block scrambling and the pixel point value disorder of the R components. The plaintext-related key sequences were respectively used in the iterative diffusion of the G , B component. The three encrypted components were distributed by forward and backward diffusion. Through simulation and security analysis,the results verify the viability of the algorithm,which shows its high key sensitivity and security.