Secure data transmission by use of encrypted digital holograms and an optical retrieval system for secure real-time display are proposed. Original images are encrypted by a double-random phase encryption technique and then are recorded as digital holograms in a CCD, together with a reference plane wave. This digital hologram of the encrypted image can be transmitted to receivers via any conventional electronic or digital communication channels. The decryption key is also recorded as a digital hologram. At the receiver, the original image can be retrieved by an optical correlation-based reconstruction process. Both encryption and retrieval can be performed by all-optical means, and thus a real-time secure display can be implemented. We demonstrate the proposed system numerically and experimentally.
© 2002 Optical Society of America
(100.1160) Image processing : Analog optical image processing
(100.3010) Image processing : Image reconstruction techniques
(100.4550) Image processing : Correlators
(200.4560) Optics in computing : Optical data processing
Osamu Matoba and Bahram Javidi, "Optical retrieval of encrypted digital holograms for secure real-time display," Opt. Lett. 27, 321-323 (2002)