US 2004/0003268 A1Published application

Using a rights template to obtain a signed rights label (SRL) for digital content in a digital rights management system

AssigneeMicrosoft Corporation

InventorsSteven Bourne, Chandramouli Venkatesh, Vinay Krishnaswamy

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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 retrieved from a rights template and protected according to (PU-DRM). The protected items and a digital signature from the rights template are submitted as a rights label to the license server for signing. The license server verifies the rights template signature, and if such signature verifies signs the rights label 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.

Claims19

Dependent claims

A method of publishing digital content to enable a license server to issue a digital license corresponding to the content to one or more users desiring to render the content, the method comprising:

encrypting the content according to a content key (CK) to result in (CK(content));
protecting the content key (CK) according to a public key for the license server (PU-DRM);
retrieving a rights template and retrieving rights data to be associated with the content from the rights template;
protecting the retrieved rights data according to (PU-DRM);
submitting the protected rights data and the protected content key (CK)) as a rights label to the license server for signing thereby, the license server validating the rights label and, if valid, creating a digital signature based on a private key (PR-DRM) corresponding to (PU-DRM) and based at least in part on the protected rights data to result in a signed rights label (SRL) and returning the SRL;
receiving the returned SRL and concatenating such received SRL with (CK(content)) to form a content package;
and
distributing the content package to the one or more users, whereby a user desiring to render the content retrieves the SRL from the content package and submits the retrieved SRL to the license server as part of a request for the license corresponding to the content, whereby the license server verifies the signature of the SRL based on (PU-DRM) and based at least in part on the protected rights data, accesses the protected rights data in the SRL and reviews same to determine whether the user is entitled to the license, and if so issues the license to the user, the license including (CK) in a protected form accessible to the user.

5 more elements

A method for a license server to provide a signed rights label (SRL) to a user, the SRL to be submitted to the license server to obtain therefrom a digital license for allowing rendering of corresponding published digital content, the content being encrypted according to a content key (CK) to result in (CK(content)), the method comprising:

receiving from the user a rights label including (CK) protected according to a public key for the license server (PU-DRM), rights data retrieved from an official rights template (ORT) and protected according to (PU-DRM), and a digital signature from the ORT, the signature being based on a private key (PR-DRM) corresponding to (PU-DRM) and based at least in part on the rights data in the ORT (S (PR-DRM-T));
verifying S (PR-DRM-T) based at least in part on the protected rights data in the rights label;
validating the rights label;
and
if S (PR-DRM-T) verifies and the rights label validates:
creating a digital signature based on (PR-DRM) and based at least in part on the protected rights data (S (PR-DRM-L);
attaching S (PR-DRM-L) to the received rights label to result in the signed rights label (SRL);
and
returning the SRL to the user, the user receiving the returned SRL, concatenating such received SRL with (CK(content)) to form a content package, and distributing the content package to the one or more users, whereby a user desiring to render the content retrieves the SRL from the content package and submits the retrieved SRL to the license server as part of a request for the license corresponding to the content, whereby the license server verifies S (PR-DRM-L) based on (PU-DRM) and based at least in part on the protected rights data, accesses the protected rights data in the SRL and reviews same to determine whether the user is entitled to the license, and if so issues the license to the user, the license including (CK) in a protected form accessible to the user.

6 more elements

Dependencies are inferred from the claim text.