A Practical Holographic Encryption/Decryption Technique

Abstract

A digital holographic decryption technique is proposed to decode holograms that are printed as gray-scale images. Firstly, holograms are computer-generated and encoded digitally with a conventional holographic encoding method.Phase distributions of the encoded holograms are then converted into gray-scale images, which can be printed on surfaces of various objects. A CCD device is used to capture the printed images, which are then adjusted to match the original holograms. Finally, the adjusted images are converted to phase distributions and decoded digitally. The technique has high security and can be conveniently applied for protecting confidential information.