一种基于时空混沌系统的彩色图像自适应位级加密算法  

Self-adaptive Bit-level Colour Image Encryption Algorithm Based on Spatiotemporal Chaotic System

作　　者：柴秀丽[1] 甘志华[2,3] 

机构地区：[1]河南大学图像处理与模式识别研究所,开封475004 [2]北京理工大学计算机学院,北京100081 [3]河南大学软件学院,开封475004

出　　处：《计算机科学》2015年第7期204-209,共6页Computer Science

基　　金：国家自然科学基金资助项目(61004006;61203094);河南省基础与前沿技术研究项目(132300410475);河南省教育厅科技攻关项目(14A413015)资助

摘　　要：基于时空混沌系统,提出了一种新的自适应的在位级进行操作的彩色图像加密策略。首先将原始明文图像转化为R、G、B3个分量,接着采用自适应方法进行加密,即先用B加密R得到R′,用R′加密G得到G′,用G′加密B得到B′,用B′加密R′得到R″,如此循环一轮即得到加密后的密文图像。加密操作包括置乱和扩散,使用时空混沌系统CML对原始图像在位级进行置乱,然后采用Logistic系统对置乱后的二值图像进行扩散。混沌系统的初始值受明文信息的影响,使得算法对明文敏感。对密钥空间、图像直方图、密钥敏感性、相关性、信息熵、明文敏感性、密码攻击进行的测试和分析,证明了算法的安全性和高效性,其在图像保密通信领域具有巨大的应用潜力。A new self-adaptive colour image encryption scheme based on spatiotemporal chaotic system was introduced,and it operates at the bit level.Firstly,plain image is converted to R,G,Bthree vectors,and then a self-adaptive method is employed to encrypt the image.The method is as follows：Bvector image is used to encrypt Rvector image,and R′is given;R′is used to encrypt Gvector image,and G′is given;G′is used to encrypt Bvector image,and B′is gotten;B′is used to encrypt R′,and R″is attained,then cipher image appears after one turn.Encryption schemes are composed of confusion process and diffusion process.Spatiotemporal chaotic system——coupled map lattices（CML）is used to permute the positions of the image pixels at the bit level,and logistic chaotic system is adopted to diffuse the shuffled bit image.The initial values of chaotic systems are influenced by the plain image,and the method is sensitive to the plain image.Tests and analyses of key space,image histogram,key sensitivity,correlation,information entropy,plain image sensitivity and steganogram attack were carried out and the results demonstrate the superior security and high efficiency of the proposed scheme.Moreover,the encryption scheme has huge application potential in image secure communication field.

关 键 词：保密通信 彩色图像加密 时空混沌系统 自适应 位级 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]