一种新的彩色图像加密和解密算法

为实现对数字彩色图像信息的有效保护，提出一种基于Lorenz混沌序列的彩色图像加密及抗剪切攻击解密算法。对Lorenz系统输出的三维混沌序列进行改进，使其具有理想的伪随机特性。根据这三维序列依次改变RGB三分量组合图像的像素位置和像素值，从而实现图像加密；在解密时，给出一种基于邻域相邻像素特性的加密图像抗剪切攻击恢复算法。应用评价指标对加解密效果和安全性进行分析。理论分析和实验结果表明，该算法密钥空间大，具有较好的加解密效果和效率，对统计分析具有较好的安全性和较强的抗剪切攻击能力。

New Color Image Encryption and Decryption Algorithm

ha order to protect digital color image＇s information, a color image encryption algorithm based on Lorenz chaos sequence and its decryption method protect from sheafing attack are presented. 3D Lorenz chaotic sequences are improved to be with ideal pseudo-randomness. The RGB three-component combination image＇s pixel positions are shifted and the pixel value is altered based on the 3D sequence so that the image will be scrambled and encrypted. While doing the decryption, a method is provided based on the neighboring pixels characteristic to renew the image attacked by shearing. The effects of encryption, decryption and security are also analyzed by using the method of accessing. Theoretical analysis and experimental results show that the algorithm has a large space of keys, a good encryption and decryption effects and efficiency, a better security performance to statistical analysis and strongly against shearing attacks ability.