Monaghan, David S. and Situ, Guohai and Gopinathan, Unnikrishnan and Naughton, Thomas J. and Sheridan, John T. (2009) Analysis of phase encoding for optical encryption. Optics Communications, 282 (4). pp. 482-492. ISSN 0030-4018

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Abstract

A phase encoded image is encrypted using the double random phase encoding technique, (DRPE). The effects of using a variable dynamic range of phase distribution during phase encoding (pre-encryption) are examined. We begin by phase encoding the input image using the full phase range, from −π to π. We perform numerically perfect encryption and we then introduce errors into the decrypting phase-keys in the form of a pseudo-random distribution (position and phase) of incorrect pixels values. By quantifying the resulting error in the attempted decryptions, for increasing amounts of error in the decrypting phase-keys, we examine the effects of reducing the phase range to, +/− (π − Δ). In this way we attempt to improve the phase encoding procedure for use with the DRPE technique. When the pixel values calculated, during an attempted decryption, fall outside the phase range used to phase encode the assigned input image, we examine different methods of redistributing the value of that pixel to an assigned value within the allowed phase range. The effects of the phase quantisation used in the keys are also examined.

Item Type:	Article
Keywords:	Optical processing; Digital image processing; Fourier optics; Numerical approximation and analysis;
Academic Unit:	Faculty of Science and Engineering > Computer Science Faculty of Science and Engineering > Research Institutes > Hamilton Institute
Item ID:	12385
Identification Number:	https://doi.org/10.1016/j.optcom.2008.10.047
Depositing User:	Thomas Naughton
Date Deposited:	07 Feb 2020 15:23
Journal or Publication Title:	Optics Communications
Publisher:	Elsevier
Refereed:	Yes
URI:	Publisher
Use Licence:	This item is available under a Creative Commons Attribution Non Commercial Share Alike Licence (CC BY-NC-SA). Details of this licence are available here

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