基于信道编码和Henon映射的图像加密方法

为同时解决图像传输的安全性和鲁棒性问题,提出一种结合LDPC编码和Henon映射的图像加密方法。将图像分解成8个二进制位平面表示,对高两位位平面进行LDPC码编码,编码后的位平面与低6位位平面重构成1024阶灰度图像;计算图像灰度值的偏差对Henon映射初值进行修正,使用Henon映射进行像素位置置乱和灰度值扩散;从10比特像素值中分离高2比特作为内部密钥,低8比特作为加密结果。实验结果表明,该方法对密钥敏感性强,密钥空间大,具有良好的加密效果,其加密结果能有效抵抗差分分析攻击,且具有较强的抗剪切和抗噪声攻击能力。

Image encryption combined channel coding with Henon mapping

To solve the problems of security and robustness of image transmission, an image encryption algorithm combined LDPC encoding with Henon mapping is proposed. Firstly, the algorithm divides the image into 8 bit-plane, uses LDPC code to encode the high 2 bit-plane and rebuilds 1024 gray image with others 6 bit-plane. Secondly, calculates its deviation acted as parity value of initial value of Henon mapping, uses Henon mapping to scramble the position of image pixels and diffuse the value of pixels. Finally, the high 2 bits is separated from 10 bits of pixel value as internal key, the others 8 bits is acted as the eneryption result. Experimental results show that the algorithm has stronger sensitive to the keys and plaintext, possesses favorable avalanche effect, and can resist plaintext attack and differential attack effectively. Moreover, encryption result has stronger ability of resisting cutting and noise attack.