Optical encryption in the axial domain using beams with arbitrary polarization

Recently, a cryptosystem based on the analysis of light in the focal area of a high numerical aperture system has been proposed. A key element in the design of this device is the selection of the polarization of the input beam. In this paper we analyze how polarization influences the performance of the encoded message. In order to avoid attacks and enhance security, the system is assumed to work in photon counting illumination conditions. (C) 2016 Elsevier Ltd. All rights reserved.