Method for insuring uniqueness of an original CD
US6188659A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 15, 1998 |
| Grant date | Feb 13, 2001 |
| Priority date | — |
| Expiry date | Dec 15, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B20/00086
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The invention provides a method of proving that a CD is an authorized original by utilizing a unique catalog code that is stored in a sub channel data stream on the CD that is derived using digital signature techniques. The inputs for the unique catalog code are derived from a digital signature algorithm and include, in the case of audio CD, each song's ISRC number, a bar code or unique identifier of the CD and the audio data content. To verify that the CD is not a copy, the original digital signature algorithm used at the time of recording to create the unique catalog code is applied to the audio data and ISRC codes recorded on the disc to derive a catalog code. An authorized original CD will have the same catalog code value stored in the subchannel as the catalog code derived from the digital signature algorithm. If the catalog codes do not match, the disc is determined to be an illegal copy.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.