基于最小粒度全置乱的图像加密算法*

依据混沌置乱信息熵, 给出选择驱动图像比特全排列混沌映射的准则,依据混沌轨道的不可预测性，设计一个图像比特全置乱算法，应用选择的混沌完成图像最小粒度—比特全空间内最大程度的等概率置乱。为增加抗攻击能力，又根据混沌映射拉伸折叠机理，设计图像像素替换算法完成图像加密变换；分析算法密钥空间、密文数字特征、相关性、抗差分攻击能力。结果表明，该图像加密算法较Ye算法和Huang算法具有更好的置乱度、去相关性和抗差分攻击能力，能够更加有效地保护数字图像。

Algorithm of image encryption based on smallest granularity permutation

To guarantee security and privacy in image transmission and archival application,adequate efficient encryption technique are necessary.Chaotic maps can be proper alternatives.This paper proposed a criterion for choosing chaos map based on chaos permutation information entropy.It designed an algorithm for image bit permutation based on the fact that the output trajectory of chaotic system was very unpredictable.It implemented image smallest granularity scrambling,namely,bit space maximum scrambling by applyi...