基于动态分组和扩散置乱的混沌加密方法

A chaotic encryption method based on diffuse scrambling and dynamic grouping

为了提高图像加密的安全性和有效性,提出一种基于动态分组和扩散置乱的混沌加密方法。将明文图像随机分组并采用比特位和行列的置乱、扩散操作对其加密,其密钥流产生于基于明文图像的逻辑映射,扰乱明文图像和密文图像之间的映射关系;并且在进一步加密过程中,明文图像像素由密文图像反馈算法取代,使得加密过程受到明文图像控制参数的影响。理论分析和实验测试结果表明,该算法可以抵御选择性攻击和差分攻击,具有较好的统计特性,可以运用于图像信息安全保护。

In order to improve the effectiveness and safety of image encryption,a dynamic group-ing and diffuse scrambling chaotic encryption algorithm is proposed.In the encryption algorithm, the plain-image is divided into several groups randomly,and permutation-diffusion process on bit level and row is carried out.The key stream generated by logistic map is related to the plain-im-age,which confuses the relationship between the plain-image and the cipher-image.In the process of further encryption,the image pixels are substituted by cipher-image feedback algo-rithm.This can relate encryption required parameters with plain-image and thus the cipher-image is obviously changed when the plain-image has a small disturbance.Theoretical analysis and ex-perimental results show that the algorithm has high security and better statistical properties to resist selective attack and differential attack.This algorithm thus can be widely applied in the field of image information security protection.