基于Henon映射的数字图像加密

通过对目前普遍应用于数字图像加密的几种混沌系统进行分析比较，提出将Henon映射应用于图像加密．由于Henon映射所产生的混沌序列不满足均匀分布，可以利用王英等人提出的小数点右移去整的方法使之近似均匀分布．在对此方法移位参数限制的基础上，对混沌序列进行处理，得到更适合图像加密的伪随机序列．利用改进后的序列生成变换和置乱矩阵，对图像进行按位异或和置乱等加密运算．仿真结果表明，该算法可以达到较好的加密效果，并且具有较强的抗攻击性能．

Image Encryption Based on Henon Map

With analysis and comparison of several chaotic systems generally applied on image encryption, the Henon map is proposed for image encrypting. Owing to the non-uniform distribution of sequence generated by Henon map, Wang Ying’s method is adopted, which lateralizes the decimal point to right direction and clips the integer part. The lateral parameter of Wang Ying’s method is limited in the treatment of chaotic sequence as to get a more suitable pseudo-random sequence in the progress of image encryption. Then a transfer matrix and a confusion matrix is used, which are generated by the pseudo-random sequence to exclusive or the bits of the pixels and scramble the location of image. Simulation results indicate that the algorithm can reach a better effect in image encryption and have strong anti-attacking performance.