Document copying deterrent method using line and word shift techniques
US5629770A · kind A · utility
158Cited by
12References
16Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 31, 1995 |
| Grant date | May 13, 1997 |
| Priority date | — |
| Expiry date | Mar 31, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S283/901
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.