Digital content protection method and apparatus
US6640305B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 6, 2001 |
| Grant date | Oct 28, 2003 |
| Priority date | — |
| Expiry date | Sep 6, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2209/603
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Before use, a population of tamper-resistant cryptographic enforcement devices is partitioned into groups and issued one or more group keys. Each tamper-resistant device contains multiple computational units to control access to digital content. One of the computational units within each tamper-resistant device communicates with another of the computational units acting as an interface control processor, and serves to protect the contents of a nonvolatile memory from unauthorized access or modification by other portions of the tamper-resistant device, while performing cryptographic computations using the memory contents. Content providers enforce viewing privileges by transmitting encrypted rights keys to a large number of recipient devices. These recipient devices process received messages using the protected processing environment and memory space of the secure unit. The processing result depends on whether the recipient device was specified by the content provider as authorized to view some encrypted digital content. Authorized recipient devices can use the processing result in decrypting the content, while unauthorized devices cannot decrypt the content. A related aspect of the…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.