Method for managing security keys utilized by media devices in a local area network

• US 20070104104A1
• Filed: 11/09/2005
• Published: 05/10/2007
• Est. Priority Date: 11/09/2005
• Status: Abandoned Application

• Current Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Abu-Amara, Hosame
• Application Number:
  US11/270,160
• Publication Number:
  US 20070104104A1
• Time in Patent Office: Days
• US Class Current: 370/235
• CPC Class Codes: H04L 2209/56 Financial cryptography, e.g. electronic payment or e-cash
• CPC Class Codes: H04L 2209/603 Digital right managament [DRM]
• CPC Class Codes: H04L 2463/101 applying security measures for digital rights management data processing systems or methods, specially adapted for commerce, e.g. marketing, shopping, billing, auctions or e-commerce G06Q30/00
• CPC Class Codes: H04L 63/06 for supporting key management in a packet data network cryptographic mechanisms or cryptographic arrangements for key management H04L9/08
• CPC Class Codes: H04L 63/0823 using certificates cryptographic mechanisms or cryptographic arrangements for entity authentication involving certificates H04L9/3263
• CPC Class Codes: H04L 9/083 involving central third party, e.g. key distribution center [KDC] or trusted third party [TTP]
• CPC Class Codes: H04L 9/0891 Revocation or update of secret information, e.g. encryption key update or rekeying

Abstract

A method of an existing media device for distributing a media key to a new media device joining a local area network or revoking an existing media key. For distributing a media key, a set of key generation counter (“KGC”) values are received from the media devices (1010). Each value is then voted on based on the network keys utilized by the existing media device (1012). Next, all votes for each value are gathered from the media devices (1012). A popular values is determined from the set of values (1014). To revoke a media key, a NONCE is encrypted with the network key (1104). The encrypted NONCE is then distributed to media devices of the local area network (1108). Next, votes are gathered from the media devices of the local area network (1110). All votes are received from media devices that are able to decrypt the NONCE using the media key.

Claims

1. A method of a particular media device of a local area network for distributing a media key to a new media device joining the local area network, the local area network including a plurality of media devices, the method comprising:

receiving a set of KGC (“

key generation counter”

) values from the plurality of media devices, the KGC values corresponding to network keys utilized by the plurality of media devices;

voting on each KGC value of the set of KGC values based on the network keys utilized by the particular media device;

gathering all votes for each KGC value of the set of KGC values from the plurality of media devices;

determining at least one popular KGC value from the set of KGC values; and

ensuring that the new media device is informed of the at least one popular KGC value.

2. The method of claim 1, wherein gathering all votes for each KGC value of the set of KGC values from the plurality of media devices includes gathering a quantity of media devices utilizing the network key corresponding to each KGC value.

3. The method of claim 1, wherein determining at least one popular KGC value from the set of KGC values includes identifying the at least one popular KGC value as having the greatest quantity of votes from the plurality of media devices.

4. The method of claim 1, wherein determining at least one popular KGC value from the set of KGC values includes identifying a single popular KGC value from the set of KGC values.

5. The method of claim 1, wherein determining at least one popular KGC value from the set of KGC values comprises:

identifying a plurality popular KGC value from the set of KGC values; and

selecting the KGC value corresponding to the most recently created network key.

6. The method of claim 1, wherein gathering a set of KGC values utilized by the plurality of media devices includes executing a secure consensus algorithm to gather the set of KGC values.

7. The method of claim 6, wherein gathering all votes for each key of the set of network keys from the plurality of media devices includes executing the secure consensus algorithm a second time to gather the votes for each key of the set of network keys from the plurality of media devices.

8. The method of claim 7, further comprising executing the secure consensus algorithm a third time to identify the network key corresponding to the KGC value.

9. The method of claim 1, further comprising:

receiving an inquiry from the new media device; and

providing values of network keys utilized by the particular media device to the new device in response to receiving the inquiry.

10. A method of a particular media device of a local area network for revoking a network key utilized by at least one media device of the local area network, the method comprising:

encrypting a NONCE with the network key;

distributing the encrypted NONCE to media devices of the local area network;

gathering votes from the media devices of the local area network, all votes being received from media devices that are able to decrypt the NONCE using the media key; and

determining whether to revoke the network key based on the gathered votes.

11. The method of claim 10, further comprising:

decrypting the NONCE using the media key; and

voting whether to revoke the media key.

12. The method of claim 10, wherein gathering votes from the media devices of the local area network includes executing a secure consensus algorithm to gather the votes from the media devices.

13. The method of claim 10, wherein receiving votes from the media devices of the local area network includes receiving votes indicating whether the network key should be revoked.