周期性相位掩模用于图象加密的研究

提出了一种新的行之有效的图象加密方法．即利用两个彼此独立的周期性相位掩模分别对需要保护的图象在空域和Fourier频域进行编码，使原始图象变成噪声。其特点是解密时对相位掩模的对准精度有一定的宽容度．而且由于该相位分布具有周期性，是密钥的合法持有者唯一掌握的确定性函数，所以可以重构，给实际应用带来了便利。

Study on image encryption using periodic phase plate

A new method of image encryption is proposed in this paper.Two phase mask plate with independent periodicity are used to encode image in the both of the spatial domain and the frequency domain,so as to make the original image a noise.The characteristic of this method is when decoding,the alignment precision for the phase mask plate is allowed tolerance,and moreover,owing to the fact that the phase distribution is periodic,the owner of secure key has only in hand the decisive function and the secure key can be regenerated.It makes the practical use convenient.