Abstract: This article discussed a new color image encryption algorithm. The initial conditions of chaotic systems were taken as the initial key pairs to do XOR pre-treatment of the images.The chaotic sequences generated by Logistic mapping and Lorenz system were used to scramble and diffuse the images. The algorithm used the processed image data as the initial value of Logistic mapping,and coupled Lorenz system with Logistic mapping,greatly to improve the security. The algorithm has good scrambling and diffusion effects, high encryption and decryption speed, and good anti-noise ability.

Key words: colour image, lorenz chaotic system, logistic map, coupling, enoryption algorithm

摘要： 讨论了一种新的彩色图像加密的算法。该算法以Lorenz混沌系统的初始条件作为初始密钥对图像进行异或预处理，由Logistic映射和Lorenz系统产生的混沌序列分别对图像进行置乱和扩散操作。该算法以处理后图像数据作为置乱过程中Logistic映射的初始值，实现Lorenz系统与Logistic映射的耦合，大大提高了算法的安全性。该算法具有良好的置乱和扩散效果，加密解密速度快，有良好的抗噪声能力。

关键词: 彩色图像, lorenz混沌系统, Logistic 映射, 耦合, 加密算法