By John Cox
08 December 2006
Aruba and the US government's Defense Advanced Research Projects Agency
(Darpa) are working on a new project to protect companies from wireless
Researchers are developing a battery of algorithms and a software
architecture running over radio frequency sensors to measure and analyse
traffic and then react to wireless LAN (WLAN) attacks, especially to the
spoofing and evasion that are ever more common today.
There are commercial wireless intrusion-detection systems (IDS) today
from AirDefense, AirTight Networks, Network Chemistry, and Aruba itself.
But Project MAP - the acronym stands for measure, analyze and protect -
has two ambitious, distinguishing goals.
First, it is an IDS that's far more intelligent in what and how it
measures and analyses wireless traffic. Second, it is an IDS that can
handle not only the traffic from thousands of access points and clients,
but also the flood of measurement data that its own RF sensors, or
sniffers, will create.
Smarter software is needed because attacks are becoming smarter and
sneakier. "The IDS [today] may not see certain frames, or the attacker
may be doing radio frequency jamming, causing the attack to be
invisible," says Josh Wright, senior security researcher with Aruba.
"Attackers are using evasion techniques, and these are not being
addressed by today's [IDS] products."
Scalability is essential to the project's design because the RF sensors
will continuously track, collect, and combine a lot of real-time data
about a site's entire radio environment.
Launched in summer of 2005, Project MAP is funded by the Department of
Homeland Security through Darpa. The researchers are starting to analyse
the results of a test MAP deployment. Those results will guide changes,
tweaks, and refinements to the software through the first half of 2007.
By the end of 2006, researcher plan to have deployed a full-production
The pilot consists of off-the-shelf Aruba RF sniffers, which basically
are 802.11a/b/g access points that listen only for radio signals. The
MAP software listens to the traffic on all channels, measuring a range
of statistics, aggregates that information to create an accurate picture
of what's happening in the air, and then scans for evidence of attacks,
says David Kotz, a Dartmouth professor of computer science and one of
the lead MAP researchers.
Instead of trying to minimize the number of sniffers, MAP will do the
opposite, deploying lots of them to provide effective coverage of all
the access points, authorized clients, and attacking clients. "All three
devices are involved in an attack," Kotz says. "An attacker may present
itself as an access point and tell an authorized client to disassociate
[from a legitimate access point]. You may need more than one sniffer to
collect the needed data from all three of these parties, which may be
separated by some considerable distance."
MAP will also monitor aggressively all 802.11 channels for activity.
"Most other products configure their sniffers to listen to only one
channel all the time, or to rotate through all the channels, spending
the same amount of time listening to each one," Kotz says. MAP adds
intelligence; it cycles through all the channels, but spends more time
on the busiest ones. In addition, the MAP sensors can be refocused
quickly on a channel with suspicious activity. "The software says 'this
client appears to be under attack' and it tells the MAP measurement
system to get more information," Kotz says. "The measurement system
[software] refocuses and spends more time listening to that client."
MAP is intended to be effective against denial-of-service attacks, as
well as against a new category of attacks called "reduction of quality
(RoQ)." An RoQ attack doesn't deny service completely. Instead, it
degrades the quality of the connection or the available bandwidth,
either to disrupt communications for others or to get better service for
the attacker. A wireless VoIP call, for example, might stay connected
but be so plagued with dropped packets or other problems as to be
"It's hard to detect who's doing it, or even whether it's being done at
all," Henderson says. "You need much more sophisticated techniques to
detect these attacks."
If successful, MAP could create the foundation of a dynamic WLAN
security system that can monitor continuously for, and adapt to,
constantly changing attacks.
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