Create and place 2D barcode stamps on printed documents to store authentication information

摘要

A document authenticating method is disclosed by which a plurality of two-dimensional barcode stamps are generated and printed on a back side of the document forming a color mosaic pattern. Each barcode stamp by itself is a binary barcode, but the plurality of barcode stamps as a whole are printed with different colors and/or color intensities. The barcode stamps collectively encode the content of the document to be used for document authentication.