Method and System for Document Authenticity Verification

Abstract

The invention provides a system and method for secure document verification. In the preferred embodiment, embedded information consists of marks embedded in the interior of the document and are comprised of regions that have refractive index modified to carry information. In the preferred embodiment the marks are not discernable by conventional imaging, spectroscopic or optical polarization techniques, but are discernably by interferometric techniques, such as optical coherence tomography. Multiple alternate embodiments are taught.

1 . A method of uniquely identifying a document of interest, said document of interest being composed of at least a first material, comprising the steps of:
 obtaining optical coherence tomography depth scans of said first material, said first material having a first refractive index and within said first material a second material having a second refractive index, and where said second material occurs as a consequence of manufacturing of said first material;   processing said depth scans;   generating a data pattern at a predetermined depth,   where said data pattern constitutes a unique identifier said document of interest.   
     
     
         2 . The method of  claim 1  wherein said second material is introduced as an adhesive material in the course of manufacture of said document of interest. 
     
     
         3 . The method of  claim 1  further including the step of obtaining OCT depth scans of two or more layers in said first material. 
     
     
         4 . The method  claim 1  further including the step of obtaining, using optical coherence tomography, a three dimensional image of a small portion of said document of interest, which said image and location of said image serve to uniquely identify said document of interest. 
     
     
         5 . A method of uniquely identifying a document of interest, said document of interest being composed of at least a first material, comprising the steps of:
 obtaining optical coherence tomography depth scans of said first material, said first material having a first refractive index and within said first material a second material having a second refractive index, and where said second material occurs as a predetermined consequence of manufacturing of said first material;   processing said depth scans;   generating a data pattern at a predetermined depth,   where said data pattern constitutes a unique identifier said document of interest.