Hierarchical trusted code for content protection in computers
US6775779B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 6, 1999 |
| Grant date | Aug 10, 2004 |
| Priority date | — |
| Expiry date | Apr 6, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F21/57
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An architecture for protecting premium content in a nonsecure computer environment executes only a small number of code modules in a secure memory. The modules are arranged in a hierarchy of trust, where a module names other modules that it is willing to trust, and those modules in turn name other modules that they are willing to trust. A secure loader loads a security manager that oversees a number of content-providing modules for manipulating the content. A memory manager assigns permissions to various pages of the secure memory. The memory has rings of different security. The security model can be extended to program modules and other devices on the computer's bus, such as DMA controllers and peripherals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.