The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 24, 2009
Filed:
Dec. 20, 2004
Butler W. Lampson, Cambridge, MA (US);
Paul England, Bellevue, WA (US);
Butler W. Lampson, Cambridge, MA (US);
Paul England, Bellevue, WA (US);
Microsoft Corporation, Redmond, WA (US);
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.