This work describes a full phase encoding technique for digital holographic encryption based on liquid crystal spatial light modulators, which are operated in the phase modulation mode to perform the phase-encoding object and the double random phase key masks for optical Fresnel encryption. The architecture of four-step phase-shifting digital holography is used to generate the double key holograms for implementing the encryption and decryption. Experimental results show the feasibility of the full phase encoding encryption with double keys for high-data-security properties. The proposed encryption system with electrically addressed spatial light modulators provides the flexibility of the key mask design by on-line processing.
Japanese Journal of Applied Physics 47(12), pp.8838-8843