基于干涉原理的虚拟光学加密系统

提出了一种虚拟光学加密系统。该光学加密系统采用了同轴全息技术的基本架构,将被加密图像作为被记录物体,而在参考光波及干涉场光路中分别引入两个独立的随机相位板,全息面上的输出即为加密结果,这两个随机相位板即为加密及解密所用密钥。理论分析表明,在恰当设置物光波与参考光波衍射场比例的情况下,任意一灰度图像均可被加密为平稳的复随机白噪声,可以抵御盲反卷积攻击。采用计算机模拟,证实了该系统的加密效果及对抗暴力攻击的能力。研究了解密时附加参数及噪音攻击对解密结果的影响,结果表明本系统抗噪音攻击能力一般,但对附加参数有极高的敏感性。

Virtual Optical Image Encryption Based on Interference

A virtual optical encryption system is proposed. The system adopts the basic structure of in-line digital holography and the original image is taken as the object to be recorded. Two dependent random phase masks, which act as the encryption and decryption keys, are employed in both the reference light path and the interference field. The complex field in the hologram plane is the encryption result. The statistical properties of this technique is analyzed. It is shown that the encoding converts the input signal to stationary white noise if the scale coefficient is properly selected. Computer simulations prove the encryption effects and its robustness against brute-force attacks. The influence of noise and additional parameters on the decryption results is studied. The encryption system is not so robust to noise attack, but it is highly sensitive to additional parameters.