Method of producing a security document
First Claim
1. A method of producing a security document, comprising:
- providing multi-bit binary data;
forming a pattern of recesses in a metal member, said pattern having the multi-bit binary data encoded therein; and
pressing a substrate into said metal member to texture the substrate in accordance with said binary data.
1 Assignment
0 Petitions
Accused Products
Abstract
Security documents (e.g. passports, currency, event tickets, and the like) are encoded to convey machine-readable multi-bit binary information (e.g. digital watermark), usually in a manner not alerting human viewers that such information is present. The documents can be provided with overt or subliminal calibration patterns. When a document incorporating such a pattern is scanned (e.g. by a photocopier), the pattern facilitates detection of the encoded information notwithstanding possible scaling or rotation of the scan data. The calibration pattern can serve as a carrier for the watermark information, or the watermark can be encoded independently. In one embodiment, the watermark and the calibration pattern are formed on the document by an intaglio process, with or without ink. A photocopier responsive to such markings can take predetermined action if reproduction of a security document is attempted. A passport processing station responsive to such markings can use the decoded binary data to access a database having information concerning the passport holder. Some such apparatuses detect both the watermark data and the presence of a visible structure characteristic of a security document (e.g., the seal of the issuing central bank).
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Citations
3 Claims
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1. A method of producing a security document, comprising:
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providing multi-bit binary data;
forming a pattern of recesses in a metal member, said pattern having the multi-bit binary data encoded therein; and
pressing a substrate into said metal member to texture the substrate in accordance with said binary data. - View Dependent Claims (2, 3)
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Specification