Image encryption using spatial nonlinear optics

Abstract Optical technologies have been widely used in information security owing to its parallel and high-speed processing capability. However, the most critical problem with current optical encryption techniques is that cyphertext linearly related plaintext, leading possibility one can crack system by solving a set of linear equations only two from same machine. Many efforts taken last decade resolve linearity issue, but none these offers true nonlinear solution. Inspired recent advance spatial optics, here we demonstrate technique. We show that, self-phase modulation effect photorefractive crystal, proposed image technique robust against known plaintext attack based on phase retrieval. This opens up new avenue for domain.