Use A Faraday Cage And Not A Silly Steering Lock To Protect Your Car From Hackers

Image: disklok
Image: disklok

We’ve heard for a while now that hackers are taking advantage of keyless entry systems to steal modern cars in what are known as “relay attacks.” And while some folks are using old-school methods like steering wheel locks to shield themselves, there is a much simpler method.


Financial Times wrote a story last week describing how, since 2014, vehicle thefts in England and Wales have jumped 30 percent. This, the story implies, could be attributed to a new type of vehicle theft in which hackers essentially relay and amplify the signals coming from key fobs to another relay box located near the car. The signal from the second box fools keyless entry systems into thinking the keys are closer than they really are, allowing the hackers to open and operate the vehicles.

The story goes on to talk about how these “relay attacks” have led vehicle owners to invest in low-tech solutions like that weird “disklok” steering wheel lock you see above, whose sales jumped 110 percent in 2016. The story also mentions two people in London whose vehicles were hacked into and stolen, and a police recommendation to use “old-fashioned anti-theft systems like steering-wheel locks again.” The article even mentions that insurance companies are incentivizing the use of “low-tech” solutions to “fight against digitally enabled crime.”

But buying a steering wheel lock to protect your car from such a theft isn’t exactly elegant, Low-tech devices might protect parts of your car, but they doesn’t address what is actually makes your car vulnerable; the constant communication between your key fob and you car. It’s possible to block radio waves from entering or leaving your key fobs via a Faraday Cage, essentially a metal or metal-mesh shield that blocks the transmission of electromagnetic/electrostatic signals.

You could pick up a Faraday Sleeve like this one for under $100—significantly cheaper and less bulky than a fancy “disklok” steering wheel lock—to keep “relay attackers” at bay. Or, you know, you can just use an empty old Altoids can.

But a few weeks ago, the LA Times reported that an electrician in Australia used a cheaper and much more “low tech” Faraday Cage—a bag of potato chips—to trick a GPS-based tracker into letting him skip work for two years. I don’t know if that was a special bag made of a certain material (mylar?), or if that bag would attenuate a signal from a key fob as well as it allegedly attenuated a GPS signal, but it seems plausible (it’s worth noting that in a very unscientific test, my colleague Stef put her key fob in a couple of bags of chips, and was then unable to unlock her car, so this sounds plausible).

So if you’re paranoid about car hacking, and you’re looking for a Christmas gift idea, save Santa a few bucks, ditch the funny steering wheel lock, and grab a Faraday sleeve. Or perhaps just try out a couple bags of “Twisties” crisps.

Sr. Tech Editor, Jalopnik. Owner of far too many Jeeps (Including a Jeep Comanche). Follow my instagram (@davidntracy). Always interested in hearing from engineers—email me.



A Faraday keeps the hackers away.