1. Just-in-time Transition Setup
September 2004
Just-in-time Transition Setup
Nancy Cam-Winget and Rajneesh Kumar, Cisco Systems Inc
Kapil Sood and Jesse Walker, Intel Corporation
Stefano Faccin, Nokia
Michael Montemurro, Chantry Networks
Chris Durand, Spectralink
N. Cam-Winget, et al

2. Just-in-Time Security Associations
September 2004
Just-in-Time Security Associations
Allow interoperability with i and e
Reuse existing i and e mechanisms and implementations
Pre-compute PTK on the STA prior to Re-Association
Relieve computational constraints on low power clients
Establish security associations liveness and GTK at reassociation time
Integrate QoS and Security
Reuse k to optimize scanning time and AP selection based on resource availability
“Ask Forgiveness” protocols are generally more efficient than “Ask Permission” protocols
N. Cam-Winget, et al

3. Optimized Re-Association with 4-way
September 2004
Optimized Re-Association with 4-way
Client
Authenticator AP
Supplicant
Client determines new AP for roam, increments ANONCE
Generates new PTKi,
Generate 802.1X Optimized 4-way Message #2
Reassociate Request( 802.1X 4-way Message #2)
AP validates ANONCE
Generates new PTK validate 802.1X 4-way Message #2
Generate 802.1X Optimized 4-way Message #3
Reassociate Response( 802.1X 4-way Message #3)
Client validates Message #3 (process flows same as TGi)
802.1X 4-way Message #4
Client and AP can now protect 802.1X and packets
N. Cam-Winget, et al

4. AP-Transition Timeline
September 2004
AP-Transition Timeline
Current communications (including i)
Transition decision point
Data resumes
.11r Proposal:
Data
Reassoc req
4WH M4
Probe
Reassoc resp
ADDTS req
Probe Resp
4WH M1
ADDTS resp
802.11k req
Open sys auth req
4WH M2
802.11k resp
Open sys auth resp
4WH M3
N. Cam-Winget, et al