Copy protection for recorded media
US5923754A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 2, 1997 |
| Grant date | Jul 13, 1999 |
| Priority date | — |
| Expiry date | May 2, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N2005/91364
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for securely transferring an encrypted-data key and a medium key, from a media storage such as a DVD disk to an output device in a computer system, using a randomly generated first secure transfer key generated by a disk drive of the computer system, the first key having a uniqueness factor derived from a phase locked loop circuitry. The first secure transfer key is combined with an output key stored in the output device forming a second secure transfer key. The second secure transfer key is used to encrypt the data key and the medium key to form a third secure transfer key. The third secure transfer key is passed to the output device where the data key and the medium key are decrypted. The data key and the medium key are then used by the output device to decrypt encrypted program data from the disk.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.