基于gyrator变换和矢量分解的非对称图像加密方法  

Asymmetric image encryption method based on gyrator transform and vector operation

作　　者：姚丽莉[1] 袁操今[1] 强俊杰 冯少彤[1] 聂守平[1] 

机构地区：[1]南京师范大学,江苏省光电技术重点实验室,南京210023

出　　处：《物理学报》2016年第21期139-144,共6页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:61377003);南京师范大学高层次人才科研启动项目(批准号:184080H20162)、南京师范大学青年领军人才培养项目(批准号:184080H20178);江苏省高校自然科学研究重大项目(批准号:14KJA140001)资助的课题~~

摘　　要：本文结合矢量分解和gyrator变换的数学实现得到了一种新的非对称图像加密算法,它将待加密图像先通过矢量分解加密到两块纯相位板中,然后利用从gyrator变换的数学实现中推导出来的加密算法加密其中一块相位板,获得最终的实值密文.另一块相位板作为解密密钥.算法的解密密钥不同于加密密钥,实现了非对称加密,加密过程中产生的两个私钥增大了算法的安全性.数值模拟结果验证了该算法的可行性和有效性.With the rapid development of computer network technology, information security has attracted increasing attention.Due to the characteristics of multi-dimensional operation and parallel processing capability, optical image encryption techniques have been receiving more and more attention. Since the well-known double random phase encoding technique was proposed, many other methods based on optical information processing means such as the use of optical transform,interference, and polarized light encoding, have been proposed for optical image encryption. However, recent researches have demonstrated that traditional optical encryption techniques are symmetric cryptosystems, in which decryption keys are identical to encryption keys and they have been found to be vulnerable to different types of attacks, such as known plaintext and chosen plaintext attacks. To overcome this shortcoming, asymmetric cryptosystems based on nonlinear phase-truncation techniques and phase retrieval algorithm have been proposed. Asymmetric cryptosystem is a cryptographic system in which encryption keys are different from decryption keys. The encryption keys are used as public keys which are disseminated widely, and the decryption keys are used as private keys which are known only to the authorized users. So, asymmetric cryptosystem can offer a higher-level security than symmetric cryptosystem. However,asymmetric cryptosystems based on phase retrieval algorithms require a lot of computational time, and asymmetric cryptosystems based on phase-truncated Fourier transforms have been found to be vulnerable to special attack. Therefore,in this paper, a novel asymmetric image encryption method is proposed by using the gyrator transform and vector operation. The original image is encrypted into two phase masks with vector operation. One is a random phase mask and the other is a phase mask related to the original image. In the encryption process, the random phase mask is used as a phase key and the other phase mask is transformed by gyrator transfor

关 键 词：gyrator变换 非对称加密 矢量分解 实值密文 

分 类 号：TP309.7[自动化与计算机技术—计算机系统结构]