Optically-based methods and apparatus for performing document authentication

摘要

This invention teaches a method for authenticating a document. The method includes the steps of: (a) providing a document to be authenticated; (b) illuminating at least a portion of the document with laser light that exceeds a threshold fluence; (c) detecting a narrow band laser-like emission of at least one wavelength from the document in response to the step of illuminating; and (d) declaring the document to be authentic only if the laser-like emission is detected.