Re: 802.11i scope downgraded?
Harshal Chhaya
WPA was a snapshot view of part of the 802.11i standard because the
802.11 vendors needed a security solution to address the problems with
WEP and didn't want to wait till the standard was complete. WPA had a
very limited scope - fix the problems with WEP without requiring a
hardware change to the millions of products out in the market. It was
not meant as a long term security solution.
And you are right about things missing from 802.11i. Secure fast
handoff or fast roaming was originally part of 802.11i but it was not
really a security problem. So they left it for another group to handle.
The 802.11r Task Group is now addressing this.
As for DoS attacks, the group didn't address them because there were
too many to address. The fundamental radio technology is susceptible to
DoS and nothing you do in the MAC layer or in the security sub-layer
will help to solve this problem. I guess the thinking is that there are
easier way to do a DoS attack on a network than spoofing
deauthentication and disassociation packets.
Regards,
- Harshal
John F. Carr
>Back when 802.11i was still in draft form, WPA came out. WPA didn't deal
>with things like secure IBSS (ad-hoc mode), secure fast handoff, and secure
>deauthentication and disassociation. That was to be dealt with when 802.11i
>was ratified. Now that 802.11i is ratified I can find no indication of it
>covering secure deauthentication. Can anyone enlighten me on what happened?
>Or am I just missing something in the standard?
Management frame security will be addressed by 802.11w:
<http://www.wirelessweek.com/index.asp?layout=newsat2direct&starting=2&pubdate=04/05/05>
--
John Carr (j...@mit.edu)
Harshal Chhaya
I had responded to your original post last week and had included some
information on 802.11r.
Today I came to know of a new task group within 802.11 that will
address the specific issue of authenticating management frames.
Association, authentication, disassociation and deauthentication are
all management frames so the work in this task group will address the
problem of a DoS attack through unsolicited deauthentication packets.
Here is the announcement from the IEEE:
=====
The IEEE has approved work to begin on an amendment to the IEEE 802.11
standard for wireless local area networks (WLAN). The project under
development involves a wireless LAN standard amendment for WLAN devices
to support protection of management frames.
IEEE P802.11w, "Amendment to Standard for Information
Technology--Telecommunications and Information Exchange between
systems--Local and Metropolitan Area networks--Specific
requirements--Part 11: Wireless LAN Medium Access Control (MAC) and
Physical Layer (PHY) specifications: Protected Management Frames," will
provide enhancements to the IEEE 802.11 Medium Access Control layer to
make available mechanisms that enable data integrity, data origin
authenticity, replay protection, and data confidentiality for selected
IEEE 802.11 management frames.
The Task Group developing IEEE P802.11w is focused on improving the
security of IEEE 802.11 management frames, including but not limited to
action management frames and deauthentication and disassociation
frames.
=====
Regards,
- Harshal