Multiple-image encryption in an interference-based scheme by lateral shift multiplexing

In this paper, a novel multiple-image encryption method is proposed by lateral shift multiplexing of phase-only mask. Multiple images are encrypted into three phase-only masks, one of which is generated in computer and saved as the secret key, and the other two can be obtained with a simple non-iterative algorithm. The optical scheme for decryption is quite simple, and different original images could be successfully retrieved at the output plane while the secret key is laterally shifted continuously with predefined intervals. In addition, the silhouette problem, which persecuted the previous interference-based encryption scheme, is simultaneously eliminated. The feasibility and effectiveness of the proposed method are demonstrated by numerical results.