Nonlinear Double-Image Encryption in Cylindrical Diffraction-Based Scheme by Aid of Position Multiplexing

Conventional phase-truncation-based double-image encryption (PT-DIE) scheme suffers from the phase retrieval algorithm-based attack, and information disclosure issue. In this paper, we introduce cylindrical diffraction and position multiplexing into the PT-DIE scheme. Through position multiplexing, double-image are integrated together. Then the integrated image is encoded into a real-valued cyphertext and two phase-only keys (POKs) by cylindrical diffraction. The decrypted images are acquired with two POKs by inverse cylindrical diffraction, and because of that, the phase retrieval algorithm-based attack and the information disclosure issue have been thoroughly conquered from a theoretical and experimental point of view. Furthermore, the proposed scheme can be extended to encode multi-image without changing original system architecture, and incurring additional computing burden. Simulation results have been manifested the validity and the security of the proposed scheme.