基于混沌Gyrator变换与离散小波变换的多图像光学同步加密算法  

Multi-image optical encryption algorithm based on fusion of chaotic Gyrator transform and discrete wavelet transform

作　　者：薛娟[1] 刘萍[2] Xue Juan;Liu Ping(College of Information Engineering,Yangzhou Polytechnic Institute,Yangzhou 225127,China;College of Information Engineering,Yangzhou University,Yangzhou 225127,China)

机构地区：[1]扬州工业职业技术学院信息工程学院,扬州225127 [2]扬州大学信息工程学院,扬州225127

出　　处：《电子测量与仪器学报》2019年第11期136-146,共11页Journal of Electronic Measurement and Instrumentation

基　　金：国家自然科学基金(61801417);江苏省自然科学基金项目(BK20170113);江苏省教育厅支持项目(2015JSJG545)资助

摘　　要：为了实现对多幅图像的同步加密,并改善密文的安全性,提出了基于混沌Gyrator变换与离散小波变换的多图像光学同步加密算法。首先,引入离散小波变换(DWT),对多幅明文实施分解,得到各自对应的低频与高频系数;再将所有明文的高频、低频信息分别组合为对应的映射图像;利用压缩感知(CS)方法,将高频映射图像分割为2个矩阵;借助复数理论,将其中一个矩阵与低频映射图像组合成复数图像;基于混沌Gyrator变换,对复数图像完成光学调制,得到对应的频谱;随后,采用相位截断操作来处理Gyrator频谱,获取幅度信息,并将其作为虚数,联合第二个感知矩阵,得到新的幅度复数图像;利用不同角度的Gyrator变换和新的调制掩码,通过光电装置,对幅度复数图像进行干涉,得到对应的Gyrator频谱。基于相位截断操作,保留Gyrator频谱的幅度成分,将其作为加密密文。实验结果显示,所提算法可以较好地完成多图像的同步加密,较其他光学加密技术而言,且其输出的密文具备更好的安全性。In order to achieve synchronous encryption of multiple images and improve the security of cipher, a multi-image optical encryption algorithm based on the fusion of chaotic gyrator transform and discrete wavelet transform is proposed in this paper. Firstly, discrete wavelet transform is introduced to decompose multiple plaintext, and the corresponding low-frequency and high-frequency coefficients are obtained. Then, the high-frequency and low-frequency information of all plaintext are combined into corresponding map images respectively. Compressive sensing was introduced to segment the high frequency map images into two matrices. By means of complex theory, one of the matrices was combined with the low frequency map image to form complex image. Optical modulation of complex image was completed to obtain the corresponding spectrum based on chaotic gyrator transform. Then, the gyrator spectrum was processed by phase truncation to get the amplitude information which as the imaginary part, and the second perception matrix was combined to obtain a new amplitude complex image. By using gyrator transform from different angles and new modulation mask, the amplitude complex image was interfered by photoelectric device to obtain the corresponding gyrator spectrum. Finally, the amplitude component of gyrator spectrum was retained based on phase truncation, which takes as the encrypted cipher. The experimental results show that the proposed algorithm can achieve multi-image synchronization encryption better, and its output ciphertext has better security than other optical encryption technologies.

关 键 词：多图像光学加密 离散小波变换 映射图像 压缩感知 混沌Gyrator变换 相位截断 

分 类 号：TP391[自动化与计算机技术—计算机应用技术] TN919.8[自动化与计算机技术—计算机科学与技术]