IP Library Granted Patent US 7,570,768
Granted Patent B2
US 7,570,768 · App. 10/632,274 · Granted Aug 4, 2009

Systems, structures, and methods for decrypting encrypted digital content when a rights management server has been decommissioned

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Quick Facts
Patent No.
US 7,570,768
App. No.
10/632,274
Granted
Aug 4, 2009
Kind
B2
Abstract

A method is disclosed for rendering content encrypted according to a cryptographic key, where the content has corresponding rights data including a decryption key (KD) for decrypting the encrypted content, and where (KD) in the rights data is encrypted according to a public key of a rights management (RM) server (PU-RM) to result in (PU-RM(KD)). The RM server normally delivers (KD) within a license, but upon being decommissioned can no longer issue such license. In the method, a notification is received that the RM server has been decommissioned, and thereafter an attempt is made to render a piece of content. Such content is determined to be protected to the decommissioned RM server, and a request is sent to the decommissioned RM server for the content key (KD) for the content rather than any license. Thereafter (KD) is received from the decommissioned RM server.

Claims (22)

1. A method for rendering content encrypted according to a cryptographic key, the content having corresponding rights data including a decryption key (KD) for decrypting the encrypted content, (KD) in the rights data being encrypted according to a public key of a rights management (RM) server (PU-RM) to result in (PU-RM(KD)), whereby only the RM server having a private key (PR-RM) corresponding to (PU-RM) can apply same to (PU-RM(KD)) from the rights data to obtain (KD), and whereby the RM server normally delivers (KD) within a license that is bound to the content, and whereby the RM server upon being decommissioned can no longer issue any such license, the method comprising:

receiving a notification that the RM server has been decommissioned;

attempting to render a piece of content;

determining that such content is protected to the decommissioned RM server;

sending a request to the decommissioned RM server for the content key (KD) for the content rather than any license; and

receiving (KD) from the decommissioned RM server.

2. The method of claim 1 comprising sending the request including the rights data corresponding to the content, whereby the RM server retrieves (KD) from the rights data.

3. The method of claim 1 comprising receiving (KD) from the decommissioned RM server in a non-protected form.

4. The method of claim 1 comprising receiving (KD) from the decommissioned RM server encrypted according to a public key (PU) to result in (PU(KD)), and further comprising applying a corresponding private key (PR) to (PU(KD)) to result in (KD).

5. The method of claim 1 further comprising applying (KD) to the content to reveal same in a naked form without any RM protection.

6. The method of claim 5 further comprising saving the content in the naked and non-protected form.

7. A computer-readable medium having stored thereon computer-executable instructions for performing a method for rendering content encrypted according to a cryptographic key, the content having corresponding rights data including a decryption key (KD) for decrypting the encrypted content, (KD) in the rights data being encrypted according to a public key of a rights management (RM) server (PU-RM) to result in (PU-RM(KD)), whereby only the RM server having a private key (PR-RM) corresponding to (PU-RM) can apply same to (PU-RM(KD)) from the rights data to obtain (KD), and whereby the RM server normally delivers (KD) within a license that is bound to the content, and whereby the RM server upon being decommissioned can no longer issue any such license, the method comprising:

receiving a notification that the RM server has been decommissioned;

attempting to render a piece of content;

determining that such content is protected to the decommissioned RM server;

sending a request to the decommissioned RM server for the content key (KD) for the content rather than any license; and

receiving (KD) from the decommissioned RM server.

8. The medium of claim 7 wherein the method comprises sending the request including the rights data corresponding to the content, whereby the RM server retrieves (KD) from the rights data.

9. The medium of claim 7 wherein the method comprises receiving (KD) from the decommissioned RM server in a non-protected form.

10. The medium of claim 7 wherein the method comprises receiving (KD) from the decommissioned RM server encrypted according to a public key (PU) to result in (PU(KD)), and further comprising applying a corresponding private key (PR) to (PU(KD)) to result in (KD).

11. The medium of claim 7 wherein the method further comprises applying (KD) to the content to reveal same in a naked form without any RM protection.

12. The medium of claim 11 wherein the method further comprises saving the content in the naked and non-protected form.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Dec 9, 2014
From: MICROSOFT CORPORATION
To: MICROSOFT TECHNOLOGY LICENSING, LLC
Reel/Frame 034541/0477 →