Copy protection through symbol substitution and induced errors
US6715122B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 23, 2001 |
| Grant date | Mar 30, 2004 |
| Priority date | — |
| Expiry date | Jan 22, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B20/00086
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Method and apparatus for preventing unauthorized replication of a digital data file. A plurality of second data set samples are substituted for a plurality of user data samples in a user data sequence to generate a combined data set. Error correction codes are calculated to correct errors in the combined data set. Uncorrectable errors are then intentionally written to the error correction codes corresponding to the second data set samples so that, during playback, the readback system conceals the corresponding second data set samples. An unauthorized copy of the digital data file will not include the uncorrectable errors; thus, the same readback system will output both the user data samples and the second data set samples, with the second data set samples interfering with the integrity of the user data samples.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.