Mechanism to update current session parameters Month Year September 2006 September 2006 Mechanism to update current session parameters Date:2006-08-20 Authors: Notice: This document has been prepared to assist IEEE 802.11. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release: The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution, and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEE’s name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEE’s sole discretion to permit others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that this contribution may be made public by IEEE 802.11. Patent Policy and Procedures: The contributor is familiar with the IEEE 802 Patent Policy and Procedures <http:// ieee802.org/guides/bylaws/sb-bylaws.pdf>, including the statement "IEEE standards may include the known use of patent(s), including patent applications, provided the IEEE receives assurance from the patent holder or applicant with respect to patents essential for compliance with both mandatory and optional portions of the standard." Early disclosure to the Working Group of patent information that might be relevant to the standard is essential to reduce the possibility for delays in the development process and increase the likelihood that the draft publication will be approved for publication. Please notify the Chair <stuart.kerry@philips.com> as early as possible, in written or electronic form, if patented technology (or technology under patent application) might be incorporated into a draft standard being developed within the IEEE 802.11 Working Group. If you have questions, contact the IEEE Patent Committee Administrator at <patcom@ieee.org>. Sood, Walker, Jalfon Sood, Walker

Month Year September 2006 September 2006 Abstract STA implementations use (re)association request messages to update their current session parameters. This proposal introduces one mechanism to clearly separate the means for updating session parameters to be distinct from an actual (re)associate state. Sood, Walker, Jalfon Sood, Walker

Agenda Problem Statement Suggested mechanism Conclusions Month Year September 2006 September 2006 Agenda Problem Statement Suggested mechanism Conclusions Sood, Walker, Jalfon Sood, Walker

Month Year September 2006 September 2006 Problem Statement Some current STA implementations use (re)associate request messages to their AP to update the session parameters So, why is this a problem? (re)Associate semantics dictate that STA is requiring a new connection REV-ma-D7.0-Redine: 11.3.2.2 – STA be explicitly disconnected; e.g. service disruption REV-ma-D7.0-Redline: 8.4.10 – SAs be deleted, especially PTKSA REV-ma-D7.0-Redline: 5.4.2.3 – Reassociation can update params Lack of instance identifiers in (re)associate messages make it impossible for AP to differentiate an existing session from a new one In summary: update of security parameters should not be overloaded to (re)associate requests unless disruption of service is acceptable! STAs need a cleaner mechanism to update its current session parameters with the associated AP Sood, Walker, Jalfon Sood, Walker

Month Year September 2006 September 2006 Problem not solved by 802.11r 11r uses (ANonce, SNonce) combination as a session identifier, which is also included in (re)association messages 11r requires the use of 11r authentication prior to (re)association to create a PTKSA If 11r AKM is negotiated, a STA wanting to update its session parameters using (re)associate must derive a new PTKSA. Pretty burdensome, right? Especially, for low-powered STAs Causes disruption in existing connection due to new 11r handshake Sood, Walker, Jalfon Sood, Walker

Proposed Mechanism New Class 3 Action Frame Category: Session Update Month Year September 2006 September 2006 Proposed Mechanism New Class 3 Action Frame Category: Session Update Action Field Values Action field value Description 1 Session-Update Request 2 Session-Update Response Sood, Walker, Jalfon Sood, Walker

Session-Update Request Format Month Year September 2006 September 2006 Session-Update Request Format In an ESS, this message if sent from a non-AP STA to its currently associated AP AP Address Capability Information Listen Interval Supported Channels QoS Capability Category Action Request ID AID Octets: 1 1 1 2 6 Variable, Defined Elsewhere Additional IEs (Incl. Vendor Specific) can be appended to this frame, as needed RSN is not included Sood, Walker, Jalfon Sood, Walker

Session-Update Response Format Month Year September 2006 September 2006 Session-Update Response Format In an ESS, this message if sent from an AP to its associated non-AP STA, as a response to a prior Request AID STA Address Capability Information Listen Interval Supported Channels QoS Capability Category Action Request ID Octets: 1 1 1 2 6 Variable, Defined Elsewhere Shall match the Session-Update Request-ID Accepted or Suggested Values Sood, Walker, Jalfon Sood, Walker

Session-Update Procedure Month Year September 2006 September 2006 Session-Update Procedure STA AP Successful Authentication and Association – 11i or 11r Session-Update-Request(Req-ID, List-of-Params, IEs) Session-Update-Response(Req-ID, List-of-Params, IEs) Sood, Walker, Jalfon Sood, Walker

Confidentiality, Authentication, and Replay Protection Month Year September 2006 September 2006 Confidentiality, Authentication, and Replay Protection The proposed Action Frame is sent only after a STA has a successful and current association with an AP TGw requirements (Done) and protocol (work-in-progress) for Unicast Action Frames protection will provide protection against eavesdropping, in-flight modification (integrity), MITM, and replay attacks. Sood, Walker, Jalfon Sood, Walker

Month Year September 2006 September 2006 Summary Provide a clean and secure mechanism for a STA to update its session parameters with its associated AP Eliminate semantic overload of the (re)association message Sood, Walker, Jalfon Sood, Walker