James W Shobe

US Patent:

20040003270, Jan 1, 2004

Filed:

Jun 28, 2002

Appl. No.:

10/185527

Inventors:

Steven Bourne - Seattle WA, US
Prashant Malik - Bellevue WA, US
Vinay Krishnaswamy - Woodinville WA, US
James Shobe - Seattle WA, US
Chandramouli Venkatesh - Sammamish WA, US
Attila Narin - Bothell WA, US

Assignee:

Microsoft Corporation

International Classification:

H04L009/00

US Classification:

713/193000

Abstract:

Content is encrypted according to a content key (CK) ((CK(content))), (CK) is protected according to a license server public key (PU-DRM), and rights data associated with the content is protected according to (PU-DRM). The protected items are submitted as a rights label to the license server for signing. The license server validates the rights label and, if valid, digitally signs based on the protected rights data to result in a signed rights label (SRL), and returns same. The SRL is concatenated with (CK(content)) and both are distributed to a user. To render the content, the user submits the SRL to the license server to request a license. The license server verifies the SRL signature and reviews the SRL protected rights data to determine whether the user is entitled to the license, and if so issues the license, including (CK) in a protected form accessible to the user.