Method and apparatus for providing a key for secure communications

• US 7,461,253 B2
• Filed: 11/20/2006
• Issued: 12/02/2008
• Est. Priority Date: 11/22/2005
• Status: Active Grant

• Current Assignee: ARRIS Enterprises LLC (CommScope Holding Company, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Emeott, Stephen P., Braskich, Anthony J.
• Primary Examiner(s): Simitoski, Michael J
• Application Number:
  US11/561,443
• Publication Number:
  US 20080016350A1
• Time in Patent Office: 743 Days
• Field of Search: 713/168, 713/169, 726/2, 380/284, 370/331, 455/411, 709/227, 709/228
• US Class Current: 713/169
• CPC Class Codes: H04L 2209/12 Details relating to cryptographic hardware or logic circuitry
• CPC Class Codes: H04L 2209/601 Broadcast encryption
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: H04L 63/065 for group communications cryptographic mechanisms or cryptographic arrangements for key management involving conference or group key H04L9/0833
• CPC Class Codes: H04L 63/162 at the data link layer
• CPC Class Codes: H04L 9/0833 involving conference or group key network architectures or network communication protocols for key management in group communication in a packet data network H04L63/065
• CPC Class Codes: H04L 9/0869 involving random numbers or seeds
• CPC Class Codes: H04L 9/088 Usage controlling of secret information, e.g. techniques for restricting cryptographic keys to pre-authorized uses, different access levels, validity of crypto-period, different key- or password length, or different strong and weak cryptographic algorithms network architectures or network communication protocols for using time-dependent keys in a packet data network H04L63/068
• CPC Class Codes: H04L 9/321 involving a third party or a trusted authority
• CPC Class Codes: H04L 9/3273 for mutual authentication network architectures or network communication protocols for achieving mutual authentication in a packet data network H04L63/0869

Abstract

A method and apparatus for providing a key for secure communications is provided herein. During operation a node wishing to join a network, will authenticate with an authentication server and then derive a pairwise key (e.g., a Pair-wise Transient Key (PTK)) used for encryption of unicast traffic. The node will also create its own group transient key (GTK) for use in encrypting multicast or broadcast traffic. Once the GTK is generated, it will be provided to an authenticator as part of an association request message.

Claims

1. A method for mutual authentication of a first and a second node in a peer-to-peer network, the method comprising the steps of:

sending a first authentication message to the second node containing information needed to authenticate the first node;

receiving a second authentication message from the second node echoing at least some of the information transmitted in the first authentication message;

determining responsive to the contents of the received second authentication message whether authentication is needed;

deriving a pair-wise transient key (PTK) used for encryption of unicast traffic from a pair-wise master key created during authentication;

sending an association message to the second node, the association message comprising both information needed by the second node to validate the PTK, and a group transient key (GTK) used by the first node in encrypting multicast or broadcast traffic; and

receiving an association message from the second node, the association message comprising information needed by the first node to validate the PTK, and a GTK used by the second node, wherein the first authentication message comprises a nonce created by the first node and the second authentication message comprises a nonce created by the second node.

2. The method of claim 1 wherein the association message sent to the second node is an association request message.

3. The method of claim 1 wherein the association message received from the second node is an association response message.

4. The method of claim 1 wherein the first authentication message comprises information needed for the second node to authenticate the first node.

5. The method of claim 4 wherein the second authentication message comprises information needed by the first node for the first node to be authenticated by the second node.

6. The method of claim 1 wherein the information in the association message needed by the second node to validate the PTK comprises a Robust Security Network (RSN) information element identifying the pair-wise master key used for deriving the PTK, and a message integrity check value calculated using the PTK.

7. The method of claim 1 wherein the information in the association message needed by the first node to validate the PTK comprises an RSN information element identifying the pair-wise master key used for deriving the PTK, and a message integrity check value calculated using the PTK.

8. An apparatus for performing mutual authentication, the apparatus comprising:

a transmitter sending a first authentication message to a second node containing information needed to authenticate a first node;

a receiver receiving a second authentication message from the second node echoing at least some of the information transmitted in the first authentication message;

a logic unit determining responsive to the contents of the received second authentication message whether authentication is needed and deriving a pair-wise transient key (PTK) used for encryption of unicast traffic from a pair-wise master key created during authentication; and

wherein the transmitter additionally transmits an association message to the second node, the association message comprising both information needed by the second node to validate the PTK, and a group transient key (GTK) used by a first node in encrypting multicast or broadcast traffic; and

the receiver additionally receives an association message from the second node, the association message comprising information needed by the first node to validate the PTK and a GTK used by the second, wherein the first authentication message comprises a nonce created by the first node and the second authentication message comprises a nonce created by the second node.

9. The apparatus of claim 8 wherein the association message sent to the second node is an association request message.

10. The apparatus of claim 8 wherein the association message received from the second node is an association response message.

11. The apparatus of claim 8 wherein the first authentication message comprises information needed for the second node to authenticate the first node.

12. The apparatus of claim 11 wherein the second authentication message comprises information needed by the first node for the first node to be authenticated by the second node.

13. The apparatus of claim 8 wherein the information in the association message needed by the second node to validate the PTK comprises a Robust Security Network (RSN) information element identifying the pair-wise master key used for deriving the PTK, and a message integrity check value calculated using the PTK.

14. The apparatus of claim 8 wherein the information in the association message needed by the first node to validate the PTK comprises an RSN information element identifying the pair-wise master key used for deriving the PTK, and a message integrity check value calculated using the PTK.