基于球面波照射的非对称光学图像加密

为了克服基于相位截断傅里叶变换的非对称光学图像加密系统不能抵御已知明文攻击的缺陷,采用球面波的自带因子扰乱输入图像空间信息的方法实现图像的加解密,并通过理论分析和实验仿真进行了研究。结果表明,该方法既能抵御已知明文攻击和保持非线性特性,又能获得原系统加解密图像的效果,同时还能减少相位掩膜数量,简化系统设置。这一结果对于改进基于相位截断傅里叶变换的非对称光学图像加密系统的安全性是有帮助的。

Asymmetric optical image cryptosystem based on spherical wave illumination

In order to overcome the known plaintext attack which the asymmetric optical image cryptosystem based on phase-truncated Fourier transforms can not resist, an encryption method based on phase-truncated Fourier transforms was proposed by employing the phase factor of the spherical wave under the spherical wave illumination. The theoretical analysis and experiment results indicate that the proposed encryption method can maintain the asymmetric characteristic of the cryptosystem and avoid various types of the currently existing attacks, especially the known plaintext attack, which the asymmetric cryptosystem based on phase-truncated Fourier transforms can not resist. The results are helpful for the security improvement of the asymmetric optical image cryptosystem based on phase-truncated Fourier transform.