OPTICAL SECURITY SYSTEM WITH FOURIER PLANE ENCODING

We propose a new technique for security verification of personal docum ents and other forms of personal identifications such as LD cards, pas sports, or credit cards. In this technique a primary pattern that migh t be a phase-encoded image is convolved by a random code. The informat ion is phase encoded on the personal document. Therefore the informati on cannot be reproduced by an intensity detector such as a CCD camera. An optical processor based on the nonlinear joint transform correlato r is used to perform the verification and the validation of documents with this technique. By verification of the biometrics information and the random code simultaneously, the proposed optical system determine s whether a card is authentic or is being used by an authorized person . We tested the performance of the optical system for security and val idation in the presence of input noise and in the presence of distorti on of the information on the card. The performance of the proposed met hod is evaluated by use of a number of metrics. Statistical analysis o f the system is performed to investigate the noise tolerance and the d iscrimination against false inputs for security verification. (C) 1998 Optical Society of America