Methods and apparatus for maintaining secure connections in a wireless communication network

• US 8,881,305 B2
• Filed: 07/13/2009
• Issued: 11/04/2014
• Est. Priority Date: 07/13/2009
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Blackberry Limited
• Inventors: Salomone, Leonardo Jose Silva
• Primary Examiner(s): Chai, Longbit
• Application Number:
  US12/501,633
• Publication Number:
  US 20110010539A1
• Time in Patent Office: 1,940 Days
• Field of Search: 726/29
• US Class Current: 726/29
• CPC Class Codes: H04L 2209/80 Wireless
• CPC Class Codes: H04L 63/068 using time-dependent keys, e.g. periodically changing keys cryptographic mechanisms or cryptographic arrangements for controlling usage of secret information H04L9/088
• CPC Class Codes: H04L 63/162 at the data link layer
• CPC Class Codes: H04L 65/1069 Session establishment or de-establishment
• CPC Class Codes: H04L 65/1083 In-session procedures
• 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 9/3271 using challenge-response
• CPC Class Codes: H04W 12/04 Key management, e.g. using generic bootstrapping architecture [GBA]
• CPC Class Codes: H04W 12/0431 Key distribution or pre-distribution; Key agreement
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 88/02 Terminal devices
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

In one illustrative example, a method in a mobile communication device operating in a wireless local area network (WLAN) involves performing, via a wireless AP of the WLAN, a first authentication procedure with an authentication server for obtaining a first session key and a key lifetime value associated with the first session key; establishing a first secure connection with the wireless AP based on the first session key; setting a timer with an initial value that is less than or equal to the key lifetime value, and running the timer; communicating in a media session over the first secure connection with the wireless AP; and in response to an expiration of the timer during the media session: performing, during the media session, a second authentication procedure with the authentication server for obtaining a second session key; and establishing, during the media session, a second secure connection with the wireless AP using the second session key; and communicating in the media session over the second secure connection with the wireless AP. In another illustrative example, the method involves performing the second authentication procedure with the authentication server in response to identifying a request for establishing the media session, just prior to establishing the media session.

Claims

1. A method in a mobile communication device operating in a wireless communication network, the method, comprising:

performing, via an access point of the wireless network, a first authentication procedure with an authentication server for obtaining a first session key;

establishing a secure connection with the access point using the session key;

setting a timer with an initial value that is less than or equal to a first key lifetime value associated with the first session key, and running the timer;

communicating in a media session including a voice call over the secure connection with the access point;

performing the following actions in response to an expiration of the timer during the voice call;

initiating and performing, during and without interrupting the media session that is currently executing, a second authentication procedure with the authentication server to derive a second master session key (MSK) for obtaining a second session key associated with a second key lifetime value which overlaps with the first key lifetime value;

updating, during the voice call, the mobile communication device with the second session key; and

after updating,

continuing the voice call over a second secure connection with the access point using the second session key;

wherein the performing of the actions are done without disconnecting from and without reassociating with the access point, so that the voice call is continuously maintained without disruption.

2. The method of claim 1, wherein the mobile device and the wireless network operate in accordance with an IEEE 802.11 standard, and the authentication procedures are based on Extended Authentication Procedure (EAP).

3. The method of claim 1, further comprising:

receiving, via the access point, the first key lifetime value from the authentication server.

4. The method of claim 1, wherein the acts of obtaining the first session key comprises deriving a master session key (MSK).

5. The method of claim 1, wherein obtaining the first session key comprises deriving a master session key (MSK) and subsequently deriving a pairwise master key (PMK) or transient session key (TSK) based on the MSK for use in the secure connection.

6. The method of claim 1, which is performed by computer instructions stored in a computer readable medium and executable by one or more processor devices of the station.

7. A mobile communication device configured to operate in a wireless communication network, the mobile communication device comprising:

one or more processor devices;

a wireless transceiver coupled to the one or more processor devices and operative to communicate with an access point of the wireless network;

the one or more processor devices being operative to;

perform, via the wireless transceiver, a first authentication procedure with an authentication server for obtaining a first session key;

establish, via the wireless transceiver, a secure connection with the access point using the first session key;

set a timer with an initial value that is less than or equal to a first key lifetime value associated with the first session key, and run the timer;

communicate, via the wireless transceiver, in a media session including a voice call over the secure connection with the access point;

perform the following actions in response to an expiration of the timer during the voice call;

initiate and perform, via the wireless transceiver during and without interrupting the voice call that is currently executing, a second authentication procedure with the authentication server to derive a second master session key (MSK) for obtaining a second session key associated with a second key lifetime value which overlaps with the first key lifetime value;

update, during the voice call, the mobile communication device with the second session key; and

after updating,

continue the voice call over a second secure connection with the access point using the second session key;

wherein the performing of the actions are done without disconnecting from and without reassociating with the access point, so that the voice call is continuously maintained without disruption.

8. The mobile communication device of claim 7, wherein the mobile device and the wireless network operate in accordance with an IEEE 802.11 standard, and the one or more processor devices are further operative to perform the authentication procedures based on Extended Authentication Procedure (EAP).

9. The mobile communication device of claim 7, wherein the one or more processor devices are operative to obtain the first session key by deriving a master session key (MSK) and thereafter deriving a pairwise master key (PMK) or transient session key (TSK) based on the MSK for the first secure connection.