Document copying deterrent method using line and word shift techniques
AssigneeLucent Technologies Inc.
InventorsJohn T. Brassil, Steven H. Low, Nicholas F. Maxemchuk, Lawrence P. O'Gorman
Life of this patent
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Abstract
A method is provided that deters the illicit copying of electronically published documents. It includes publishing a plurality of copies of electronically created material to be distributed to a plurality of subscribers. Each copy of subscriber's document has a unique identification code embedded in the document. The arrangement of the code on the document is based on the line-shifting and word-shifting techniques. This is to minimize the effects from noise and distortions on future illicit copies to simplify detection and decoding of the unique code. A codebook is created to correlate each unique code with each subscriber.
Claims16
A method of deterring illicit copying of electronically published documents, comprising the steps of:
- electronically creating a plurality of copies of a document for distribution to a plurality of subscribers;
- encoding each of said plurality of copies of said document with a unique identification code, said identification code being based on a combination of line-shift coding and word-shift coding;
- and
- creating a codebook to correlate each such identification code to a particular one of said plurality of subscribers.
A method of deterring illicit copying of a electronically published document, comprising the steps of:
- detecting a unique identification code on a copy of said electronically published document;
- and
- comparing said detected unique identification code on said copy of said electronically published document to a codebook to determine a particular one of a plurality of subscribers to which said unique identification code correlates, said identification code being based on a combination of line-shift coding and word-shift coding.
Dependencies are inferred from the claim text.