Method and apparatus for updating an authorization key in a communication system

• US 8,572,384 B2
• Filed: 11/30/2009
• Issued: 10/29/2013
• Est. Priority Date: 10/27/2009
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Baek, YoungKyo, Lee, Jicheol
• Primary Examiner(s): SHEHNI, GHAZAL B
• Assistant Examiner(s): Chea, Philip J.
• Application Number:
  US12/627,896
• Publication Number:
  US 20110096927A1
• Time in Patent Office: 1,429 Days
• Field of Search: 713/150, 713/168
• US Class Current: 713/171
• CPC Class Codes: H04L 2209/80 Wireless network architectures or network communication protocols for wireless network security H04W12/00
• CPC Class Codes: H04L 9/0891 Revocation or update of secret information, e.g. encryption key update or rekeying
• CPC Class Codes: H04W 12/041 Key generation or derivation
• CPC Class Codes: H04W 60/04 using triggered events

Abstract

Provided is an apparatus and method for updating an Authorization Key (AK) of a mobile station in an idle mode in a wireless communication system. The method includes transmitting a first location update request to a base station, receiving a response to the request from the base station, the response to the first location update request including a NONCE_BS, wherein the NONCE_BS is a random number associated with the base station and used for updating the AK, generating a NONCE_MS, wherein the NONCE_MS is a random number used for updating the AK, generating the AK using the NONCE_BS and the NONCE_MS, transmitting a second location update request to the base station, receiving a response to the second location update request from the base station, the response to the second location update request including the NONCE_BS and the NONCE_MS, and confirming the AK based on the NONCE_BS and the NONCE_MS.

Claims

1. A method for operating a mobile station in an idle mode to update a Pairwise Master Key (PMK)/Authorization Key (AK) in a wireless communication system, the method comprising:

transmitting a first location update request to a base station, the first location update request including a request for updating the PMK/AK;

receiving a first response to the first location update request from the base station, the first response to the first location update request including a NONCE_BS, wherein the NONCE_BS is a random number associated with the base station and used for updating the PMK of the PMK/AK;

generating a NONCE_MS, wherein the NONCE_MS is a random number used for updating the PMK;

generating the PMK/AK using the NONCE_BS and the NONCE_MS;

transmitting a second location update request to the base station, the second location update request including the NONCE_BS and the NONCE_MS;

receiving a second response to the second location update request from the base station, the second response to the second location update request including the NONCE_BS and the NONCE_MS; and

confirming the PMK/AK based on the NONCE_BS and the NONCE_MS.

2. The method of claim 1, wherein the first and second location update requests are included in AAI_RNG-REQ messages, and wherein the first and second responses to the first and second location update requests are included in AAI_RNG-RSP messages, and

wherein the AAI_RNG-REQ messages are ranging request messages and the AAI_RNG-RSP messages are ranging response messages.

3. The method of claim 1, wherein the generating of the PMK/AK comprises:

generating the PMK using the NONCE_BS and the NONCE_MS; and

generating the AK using the PMK.

4. A method for operating a base station to update a Pairwise Master Key (PMK)/Authorization Key (AK) of a mobile station in an idle mode in a wireless communication system, the method comprising:

receiving a first location update request from the mobile station, the first location update request including a request for updating the PMK/AK;

generating a NONCE_BS, wherein the NONCE_BS is a random number used for updating the PMK;

transmitting a first response to the first location update request, the first response to the first location update request including the NONCE_BS;

receiving a second location update request from the mobile station, the second location update request including the NONCE_BS and a NONCE_MS, wherein the NONCE_MS is a random number associated with the mobile station and used for updating the PMK;

transmitting the NONCE_BS and the NONCE_MS to a Paging Controller (PC)/authorization station;

receiving the AK from the PC/authorization station; and

transmitting a second response to the second location update request, the second response to the second location update request including the NONCE_BS and the NONCE_MS.

5. The method of claim 4, wherein the generating of the NONCE_BS comprises:

determining if the first location update request is valid; and

if the first location update request is determined to be valid, generating the NONCE_BS.

6. The method of claim 5, wherein the determining if the first location update request is valid comprises:

transmitting a request for an AK context to the PC/authorization station;

receiving the AK context from the PC/authorization station; and

determining if the first location update request is valid based on the AK context.

7. The method of claim 4, wherein the transmitting of the NONCE_BS and the NONCE_MS to the PC/authorization station comprises:

determining if the NONCE_BS received in the second location update request is identical to the NONCE_BS transmitted in the first response to the first location update request; and

if the NONCE_BS received in the second location update request is determined to be identical to the NONCE_BS transmitted in the first response to the first location update request, transmitting the NONCE_BS and the NONCE_MS to the PC/authorization station.

8. A method for operating a mobile station in an idle mode to update a Pairwise Master Key (PMK)/Authorization Key (AK) in a wireless communication system, the method comprising:

acquiring a NONCE_BS, wherein the NONCE_BS is a random number associated with a base station and used for updating the PMK;

generating a NONCE_MS, wherein the NONCE_MS is a random number used for updating the PMK;

generating the PMK/AK using the NONCE_BS and the NONCE_MS;

transmitting a location update request to the base station, the location update request including the NONCE_BS and the NONCE_MS;

receiving a response to the location update request from the base station, the response to the location update request including the NONCE_BS and the NONCE_MS; and

confirming the PMK/AK based on the NONCE_BS and the NONCE_MS.

9. The method of claim 8, wherein the location update request is included in an AAI_RNG-REQ message, and wherein the response to the location update request is included in an AAI_RNG-RSP message, and

wherein the AAI_RNG-REQ messages are ranging request messages and the AAI_RNG-RSP messages are ranging response messages.

10. The method of claim 8, wherein the generating of the PMK/AK comprises:

generating the PMK using the NONCE_BS and the NONCE_MS; and

generating the AK using the PMK.

11. The method of claim 8, wherein the acquiring of the NONCE_BS comprises:

transmitting a request to transition to the idle mode to the base station;

receiving a response to the request to transition to the idle mode from the base station, the response to the request to transition to the idle mode including the NONCE_BS; and

transitioning to the idle mode.

12. The method of claim 8, wherein the acquiring of the NONCE_BS comprises determining the NONCE_BS using a current NONCE_BS used in a previous AK update and a Degeneration IDentifier (DID) allocated to the mobile station during a transition to the idle mode.

13. The method of claim 12, wherein the NONCE_BS is determined using the equation,

NONCE_BS=current NONCE_BS XOR(Deregistration ID|zero padding).

14. A method for operating a base station to update a Pairwise Master Key (PMK)/Authorization Key (AK) of a mobile station in an idle mode in a wireless communication system, the method comprising:

receiving a location update request from the mobile station, the location update request including a NONCE_BS and a NONCE_MS, wherein the NONCE_BS is a random number associated with the base station and used for updating the PMK and the NONCE_MS is a random number generated by the mobile station and used for updating the PMK;

transmitting the NONCE_BS and the NONCE_MS to a Paging Controller (PC)/authorization station;

receiving the AK from the PC/authorization station; and

transmitting a first response to the location update request, the first response to the location update request including the NONCE_BS and the NONCE_MS.

15. The method of claim 14, further comprising:

receiving a request to transition to the idle mode from the mobile station;

transmitting an idle mode entry request to the PC;

receiving a second response to the idle mode entry request from the PC, the second response to the idle mode entry request including the NONCE_BS, wherein the NONCE_BS is a random number used for updating the PMK; and

transmitting a third response to the request to transition to the idle mode to the mobile station, the third response to the request to transition to the idle mode including the NONCE_BS.

16. The method of claim 14, wherein the transmitting of the NONCE_BS and the NONCE_MS to the PC/authorization station comprises:

determining if the NONCE_BS received in the location update request is identical to the NONCE_BS transmitted in the third response to the request to transition to the idle mode; and

if the NONCE_BS received in the location update request is determined to be identical to the NONCE_BS transmitted in the third response to the request to transition to the idle mode, transmitting the NONCE_BS and the NONCE_MS to the PC/authorization station.

17. A method for operating a mobile station to update a Pairwise Master Key (PMK)/Authorization Key (AK) during a zone switching in a wireless communication system, the method comprising:

receiving a first message indicating that the zone switching is to be performed from a first base station, the first message indicating that the zone switching is to be performed including a NONCE_BS, wherein the NONCE_BS is a random number associated with a second base station and used for updating the PMK;

generating a NONCE_MS, wherein the NONCE_MS is a random number used for updating the PMK;

generating the PMK/AK using the NONCE_BS and the NONCE_MS;

transmitting a second message for the zone switching to the second base station, the second message for the zone switching including the NONCE_BS and the NONCE_MS;

receiving a response to the second message for the zone switching from the second base station, the response to the second message for the zone switching including the NONCE_BS and the NONCE_MS; and

confirming the AK based on the NONCE_BS and the NONCE_MS.

18. The method of claim 17, wherein the second message for the zone switching includes an AAI_RNG-REQ message, and wherein the first message indicating that the zone switching is to be performed and the response to the message for the zone switching are included in AAI_RNG-RSP messages, and

wherein the AAI_RNG-REQ messages are ranging request messages and the AAI_RNG-RSP messages are ranging response messages.

19. The method of claim 17, wherein the generating of the PMK/AK comprises:

generating the PMK using the NONCE_BS and the NONCE_MS; and

generating the AK using the PMK.

20. The method of claim 17, wherein the second message for the zone switching transmitted to the second base station includes a Cipher-based Message Authentication Code (CMAC) based on a newly generated AK.

21. The method of claim 17, wherein the response to the second message for the zone switching received from the second base station is encrypted using a Traffic Encryption Key (TEK) based on a newly generated AK.

22. A method for operating a base station to update a Pairwise Master Key (PMK)/Authorization Key (AK) during a zone switching in a wireless communication system, the method comprising:

generating a NONCE_BS which is a random number associated with a second base station and used for updating the PMK of the PMK/AK;

transmitting a first message indicating that the zone switching is to be performed in a first base station, the first message indicating that the zone switching is to be performed including the NONCE_BS;

receiving a second message for a zone switching request containing a NONCE_MS and the NONCE_BS from a mobile station;

transmitting the NONCE_BS and the NONCE_MS to an authorization station;

receiving the AK of the PMK/AK from the authorization station; and

transmitting a response to the zone switching request in the second base station, the response to the zone switching request including the NONCE_BS and the NONCE_MS.

23. The method of claim 22, wherein the first message indicating that the zone switching is to be performed including the NONCE_BS, wherein the NONCE_BS is a random number associated with the second base station and used for updating the PMK.

24. The method of claim 22, wherein the second base station transmits the NONCE_BS and the NONCE_MS to the authorization station,

receiving the AK from the authorization station;

transmitting the response to the zone switching request, the response to the zone switching request including the NONCE_BS and the NONCE_MS; and

generating the AK by generating the PMK using the NONCE_BS and the NONCE_MS and generating the AK using the PMK.

25. The method of claim 22, wherein the second message for the zone switching is received including a Cipher-based Message Authentication Code (CMAC) based on a newly generated AK.