Patent ID: 8171567
Filing Date: 2012-05-01
Classification: B42D,G06F,G06K,G06Q,G06T,G07D,G09C,H04L,H04N

Abstract:
1. A method for self-authenticating a physical document, comprising: providing a physical document having a permanently fixed stochastically variable characteristic; measuring the stochastically variable characteristic to a precision greater than the stochastic variation, to thereby determine a randomly variable attribute of the physical document; and encoding a description of the stochastically variable characteristic and a deterministic identifier of the physical document in association with the physical document in an encoding process resistant to counterfeiting of the physical document, wherein the encoding is uniquely associated with the physical document and association with a different physical document is discoverable, wherein the encoding of a description of the stochastically variable characteristic and a deterministic identifier of the physical document in association with the physical document comprises defining a dynamic watermark which is integrated in a stock of the physical document during manufacture of a physical document stock, and wherein the dynamic watermark is formed by a calendaring roll having a digitally reconfigurable watermark.