Applications of digital holography for information security

Abstract

Secure optical storage based on a configuration of a joint transform correlator (JTC) using a photorefractive material is presented. A key code designed by an optimized algorithm so that its Fourier transform has a uniform amplitude distribution and a uniformly random phase distribution is introduced. Original two-dimensional data and the key code are placed side-by-side at the input plane. Both of them are stored in a photorefractive material as a joint power spectrum. The retrieval of the original data can be achieved with the same key code. We can record multiple two-dimensional data in the same crystal by angular multiplexing and/or key-code multiplexing.