System for copy protection of an information carrier
US7646869B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 16, 2004 |
| Grant date | Jan 12, 2010 |
| Priority date | — |
| Expiry date | Nov 24, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2220/2591
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The present invention relates to a system for copy protection of an information carrier, said system comprising a diffractive layer for delivering a speckle pattern when illuminated by a light source, a spatial filter, which is aligned with respect to the diffractive layer, for delivering a filtered optical signal from the speckle pattern and a detector array for delivering, when illuminated by said filtered optical signal, an electrical signal. Said system further comprises means for computing a cryptographic key from the electrical signal, and means for decrypting encrypted data contained in the information carrier from the cryptographic key. It finds its application in copy protection of content carriers such as optical discs or in smart cards.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.