改进的骑士巡游和位运算数字图像加密算法

Digital Image Encryption Algorithm Based on Improved Knight's Tour and Bit Operation

针对图像经过骑士巡游加密后出现块效应,且加密图像抗剪切攻击与抗统计攻击能力不强等问题,提出了一种结合整图骑士巡游置乱和位运算的数字图像加密算法.算法在离散余弦变换(DCT)域内利用与待加密图像同尺寸的骑士巡游矩阵对图像进行骑士巡游置乱,再将置乱后的图像经逆离散余弦变换(IDCT)还原到空域进行位运算操作,得到加密图像.实验结果表明,基于改进的骑士巡游和位运算的数字图像加密算法密钥量更大,安全性更高,能够更好的抵抗剪切攻击与统计攻击,从而证明了算法的有效性.

When the image is encrypted by the knight＇ s tour matrix,the encrypt image appears the following questions,such as the block effect,the anti-shear attack and anti-statistical attack abilities are not strong enough. In order to solve these problems,an algorithm of image encryption based on the whole image knight＇s tour scrambling and bit operation encryption was proposed. The focus of this algorithm was using DCT domain knight＇s tour matrix,which was the same size with the original image,to scramble the original image,then using spatial domain bit operation to encrypt the scrambled image. Experimental results showthat,the improved digital image encryption algorithm based on knight＇s tour and bit operation owns larger key quantities and higher safety; its anti-shear attack and anti-statistical attack abilities are highly improved,thus the validity of the proposed algorithm is proved effectively.