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June 21, 2005

Encrypted telemetry for IEDs

From Newsweek:
Counterinsurgency experts are alarmed by how fast the other side's tactics can evolve. A particularly worrisome case is the ongoing arms race over improvised explosive devices. The first IEDs were triggered by wires and batteries; insurgents waited on the roadside and detonated the primitive devices when Americans drove past. After a while, U.S. troops got good at spotting and killing the triggermen when bombs went off. That led the insurgents to replace their wires with radio signals. The Pentagon, at frantic speed and high cost, equipped its forces with jammers to block those signals, accomplishing the task this spring. The insurgents adapted swiftly by sending a continuous radio signal to the IED; when the signal stops or is jammed, the bomb explodes. The solution? Track the signal and make sure it continues. Problem: the signal is encrypted. Now the Americans are grappling with the task of cracking the encryption on the fly and mimicking itso far, without success. Still, IED casualties have dropped, since U.S. troops can break the signal and trigger the device before a convoy passes. That's the good news. The bad news is what the new triggering system says about the insurgents' technical abilities.

Kind of puts your communications security problems into perspective, doesn't it?

Posted by ekr at June 21, 2005 7:11 AM | Filed under:

Comments

Newsweek!? Consider the source.

Posted by: Grumpy at June 21, 2005 12:07 PM

Huh. More sophisticated than I'd have thought the average insurgent to be. Do people still think they're not getting help from certain governments?

Hrmm. If they're relying on continuous transmission, it should not be too hard to do a quick triangulation on the position of the transmitter. We just need more snipers.

Posted by: Paul at June 21, 2005 10:29 PM

The part about encryption being the hard part of the continous transmission is what makes me think Newsweek may have gotten this story wrong. Regardless of the encryption, the continous transmission can be triangulated to find the source. Perhaps we need more snipers... more UAVs... more Spectres.

Posted by: Grumpy at June 21, 2005 11:35 PM

Although, if you knew that convoys/patrols go around jamming everything in sight, couldn't you just put the transmitter on one side of the road and the explosive bit on the other? That way, finding the transmitter wouldn't help. Alternately, I suppose you could also use several simultaneous transmitters/bomb to make triangulation harder.

The NYTimes also has an
article about more refined IEDs. They claim that the insurgents are building better-shaped charges and using IR detonators. While the first part seems reasonable, wouldn't IR need to be line of sight?

Posted by: Matt Krause at June 22, 2005 6:11 AM