基于回转器变换与非等模分解的光学加密算法

Multiple color image optical encryption based on Gyrator transform and unequal modulus decomposition

摘要:

为解决当前基于干涉的多图像密码系统中易出现轮廓和串扰噪声问题，设计了基于回转器(Gyrator)变换与非等模矢量分解的多彩色图像非对称光学加密算法。将所有彩色图像分解成红、绿、蓝三基色分量，再对每种颜色分类叠加，融合成三通道形式；利用Logistic映射生成随机相位掩码，对叠加后的颜色分量进行调制处理。将调制后的图像分量分别在Gyrator变换域下进行旋转变换，形成3个复杂分布函数。利用非等模矢量分解方法，将其分解成振幅和相位均不相同的2个矢量，并将其中一个视为固定的共享矢量，另一个作为解密矢量。对共享矢量实施Gyrator逆变换，输出最终的密码图像。实验数据显示，较已有的多目标加密技术而言，该算法具备更强的抗破译能力，可以更好地解决串扰噪声问题。

Abstract:

In order to eliminate the problems of the silhouette and crosstalk noise in the interference-based and multiple image cryptosystems, an asymmetric optical cryptography mechanism for multiple color images based on Gyrator transform and unequal modulus vector decomposition is designed. Firstly, all color images are decomposed into three primary color components of red, green and blue. Then, each color is classified and superimposed, and fused into a three-channel form. The random phase mask is generated by Logistic mapping to modulate the superimposed color components. Secondly, the modulated image components are rotated under the Gyrator transform domain to form three complex distribution functions. Thirdly, it is decomposed into two vectors with different amplitudes and phases, the first vector is a fixed shared, and the second vector is a different decrypted. Finally, the shared vector is further applied with inverse Gyrator transform to produce the final password image. The encryption process is characterized by no contour, no crossover and high sensitivity. Experimental data show that the proposed algorithm has stronger anti-cracking ability than the existing multi-target encryption technology, which can better solve the problem of crosstalk noise.