Collision is a situation that occurs when two or more distinct inputs into a security system produce identical outputs, which is undesirable in security applications such as watermarking and authentication. In this report we present a study of the collision property of double random-phase encoding (DRPE) in the fractional Fourier (FRT) domain. For a decade, optical security systems operating in the FRT domain is said to have a larger key space and therefore higher security. However we find that it is still possible to produce meaningful collision from the cyphertext or a watermarking embedded in a host image even without any knowledge about the fractional orders or the random phase keys.

Date Published: 18 November 2009
PDF: 6 pages
Proc. SPIE 7512, 2009 International Conference on Optical Instruments and Technology: Optoelectronic Information Security, 751205 (18 November 2009); doi: 10.1117/12.837579

Published in SPIE Proceedings Vol. 7512:
2009 International Conference on Optical Instruments and Technology: Optoelectronic Information Security
Cunlin Zhang; Tiegen Liu, Editor(s)