Patent ID: 6590995
Filing Date: 2003-07-08
Classification: H04N

Abstract:
A method of inserting manipulation-proof digital fingerprints for an electronic document, a first copy of document being assigned to a first purchaser and a second copy of the document being assigned to a second purchaser, the method comprising:inserting a first fingerprint into the first copy at a first marking location; inserting a second fingerprint into the second copy at a second marking location, the first and second marking locations being different and being assigned as a function of a finite geometric structures having a plurality of points, the first and second marking locations being determined as function of geometric structures of the finite geometric structure so that first assigned points of the plurality of points corresponds to the first fingerprint and second assigned points of the plurality of points corresponds to the second fingerprint, the first and second assigned points partially intersecting; and performing a bit-by-bit comparison of an original of the document with the first copy to see if parts of the first fingerprint have been removed by manipulation.