1. Enhanced 802.11 Security Date: 2008-05-11 Authors: May 2009 May 2009
doc.: IEEE /0315r2
May 2009
Enhanced Security
Date:
Authors:
Dan Harkins, Aruba Networks
Dan Hakrins, Aruba Networks

2. May 2009
doc.: IEEE /0315r2
May 2009
Abstract
This document describes important security features that are missing from, or will enhance, IEEE and proposes a way to add them to IEEE
Dan Harkins, Aruba Networks
Dan Hakrins, Aruba Networks

3. Security Services in 802.11 Key Management Ciphers May 2009
Authentication: A STA can prove its identity to the network and vice versa
Authorization and Access Control: Once authenticated a STA can be given access to the network, or a subset of it, or denied access to the network.
Key derivation: each side derives a key known bound to each other.
Ciphers
Data Confidentiality: Data sent between the STA and AP is hidden from all but the source and destination of the data.
Data Integrity: The recipient of a frame is able to verify that the frame was not modified in transit and that a false frame has not been substituted for a valid frame.
Data Source Authentication: The recipient of a frame is able to ascertain the origin of the frame and it is not possible for anyone else to masquerade as the claimed originator.
Dan Harkins, Aruba Networks

4. How are These Services Provided Today?
May 2009
How are These Services Provided Today?
Wired Equivalent Privacy (WEP)
Key Management
Shared key: insecure simple proof-of-possession of a shared key
Cipher
WEP: insecure, numerous fundamental flaws in design
Robust Security Network (RSN)
802.1x: provides mutual authentication, allows for authorization and access control decision making, generates secure and cryptographically strong keys.
PSK: provides a limited type of authentication, generates weak keys that void some features of RSN ciphers.
Ciphers
TKIP: provides confidentiality, data integrity (sub-optimally), and data source authentication.
CCMP: provides confidentiality, data integrity, and data source authentication.
WEP is deprecated and should not be used. That leaves RSN as the only option available.
Dan Harkins, Aruba Networks

5. May 2009
What’s The Problem?
Cryptographically strong security is limited to one particular use case– the enterprise-- where:
a AAA server is used to aggregate security services and policy.
strict roles are enforced: clients obtain network access through APs.
Cryptographically strong security doesn’t really work for other deployments.
Small office/home office– a stand-alone AAA server is problematic.
Networks of consumer electronics devices– a stand-alone AAA server is a non-starter and there is no real “client” and “AP” role.
Mesh and peer-to-peer applications– there is no “client” and “AP” role.
The PSK mode of i’s security is fundamentally broken. This is a source of continued bad press for – “ is still not secure”.
This deficiency has resulted in another organization making a very complicated, but still not-quite secure, adjunct to i PSK mode.
Dan Harkins, Aruba Networks

6. May 2009
What’s The Problem?
The security of is centralized and role-based but is being used in ways that are neither.
If your deployment does not fall into a narrow use case your choices are cumbersome and difficult to deploy, or insecure.
The mandatory-to-implement cipher—CCMP– is slow(ish), has rigid usage requirements outside of which all security is lost, and consumes more power than other modes providing comparable security.
GCM mode is suitable for very high-throughput PHYs and requires less power than CCMP
SIV mode provides provable security when adherence to the rigid usage requirements of CCMP cannot be guaranteed.
does not have a way to accept featurettes into the standard.
Dan Harkins, Aruba Networks

7. May 2009
What’s The Solution?
A Study Group to come up with a PAR & 5C to work on:
Secure, de-centralized authentication and key management. These solutions should be suitable for a traditional ESS as well as ad hoc, mesh, and various peer-to-peer applications. They should not have strict role requirements.
A password-based key exchange resistant to passive attack, active attack and dictionary attack.
A certificate-based key exchange
Definition (not development) of new ciphers
AES-GCM: a high-performance, single-pass, cipher for authenticated encryption
AES-SIV: a misuse-resistant cipher for authenticated encryption
Dan Harkins, Aruba Networks

8. A Focus on Enhanced Security
May 2009
A Focus on Enhanced Security
Tight focus ensures timely results
Keep a focus on security enhancements to existing functionality and not creation of new security algorithms, ciphers, etc.
Much of this has already been designed– GCM, SIV, SAE– so it’s a problem of defining use in
There is a need for de-centralized security in
Use of a PSK/password is widespread and will remain so. Unfortunately it is not secure; we should make it so.
There is market demand, as shown by the work of other groups like WFA.
It makes sense for to provide it instead of hoping other organizations do it (and do it right).
Data rates keep increasing, ciphers cannot be bottlenecks!
More efficient ciphers consume less power which results in longer battery life, and it’s also green.
Do security work in a security group; keep experts focused on their area of expertise.
Dan Harkins, Aruba Networks

9. May 2009
References
NIST SP800-38D
P. Rogaway and T. Shrimpton, “Deterministic Authenticated Encryption, A Provable Security Treatment of the Key-Wrap Problem”, Advances in Cryptology– EUROCRYPT ’06, St. Petersburg, Russia, 2006.
RFC 5297
H. Krawczyk, ‘SKEME: A Versatile Secure Key Exchange Mechanism for the Internet’, Proceedings of the Internet Society Symposium on Network and Distributed Systems Security, August 1995
V. Shoup, “On Formal Models for Secure Key Exchange”. ACM Computer and Communications Security Conference, 1999.
Dan Harkins, Aruba Networks

10. May 2009
Motion
Move to request the Working Group to approve and forward to the IEEE 802 Executive Committee the creation of a new IEEE Study Group, called the Enhanced Security Study Group (ESSG), to investigate ways to provide security enhancements to on the following:
Secure, robust, de-centralized key management using public key-based and password-based credentials.
Faster, more robust, or more power-efficient ciphers to protect frames.
Upon confirmation of feasibility and per 802 operating rules, the ESSG shall draft a PAR and 5 criteria to be submitted to the WG.
Moved:
Seconded:
Yes:
No:
Abstain:
Dan Harkins, Aruba Networks