Busting Thieves By Putting Your Key in the Freezer: Boooogus!

Staff Blog

Staff Blog | Oct 14, 2015

We got an email from Marianne giving us the business for suggesting thieves can't read the code from your keyless entry remote and open your car door.

Marianne writes:

"Back in about 2010, you wrote in the Seattle Times that it is an urban legend that car thieves can steal the code to your remote keyless entry and open your car.  However, I have read later reports on the web from USA Today and others that this is happening. Had this happen to my car."
The keys that launched a thousand myths. (Car Talk)

Well, Marianne, we take umbrage at the idea that any of the advice ever dispensed by Car Talk may have been wrong or misleading. For instance, we still stand by our suggestion that Felipo Berrio Extra Virgin Olive Oil is the sure cure for a squeaky belt.

Anyway, in the answer Marianne referenced from 2010, we said:

When locking key fobs were new, back in the 1980s, they would be set to a single, permanent frequency. In those days, if a thief had the right equipment, he potentially could capture the frequency and gain access to the car.

But there are two reasons why that's extremely unlikely today. First, key fobs now jumble their codes. So each time you use the fob to lock your door, it generates a unique code that it uses only that one time. While there might be equipment capable of breaking through that system, it's more likely to be owned by the 'Ocean's Eleven' crew than by a common burglar.

Keep in mind, also, that they can't steal your car with the key fob frequency, even if they could obtain it, since the ignition system has its own immobilizer.

Uh...well. That's not exactly right. It may have been correct back when Reagan was in office and remote entry was first invented, but our pals at BestRide.com did some research to figure out what the deal is with cars built in THIS century.

"Has anybody seen my keys?" (Car Talk)

"What most people don’t realize is that the system is always on, always working, and always communicating," says Craig Fitzgerald at BestRide.com, citing a study by some smart researchers at a university in Switzerland. "The car sends short beacons via the low-frequency channel. These beacons are short 'wake-up' messages that simply verify that the key and the car are capable of communicating. More complicated 'challenge messages' go back and forth when someone tries to operate the door handle, which is where the system’s security begins to break down."

They've got charts and diagrams and everything! (Best Ride)

The main problem is that as long as the car and the key communicate, thieves with an inexpensive amplifier can trick the car into thinking the key is a lot closer than it really is, allowing them to just yank on the door handle, open the car, push the start button and drive away.

Marianne also quoted part of an article, suggesting that putting your keys in the freezer was the way to prevent thieves with an amplifier from tricking your remote system. THAT'S hooey, no matter what those dopes at USA Today have to say.

You could store a whole lotta keys in here... (Myke2020, Wikimedia Commons)

And that's debunked with actual science: "Some reporters have suggested storing the key in a freezer, but that countermeasure is ineffective, since the signal amplification is sufficient to overcome the attenuation provided by a metal box," reads the article. The scientists who did the original study said, "We note that designing a good Faraday cage is challenging."

You do have one appliance with a Faraday cage in your house, but we wouldn't suggest putting your keys in there. To find out what it is, and how you can prevent thieves from opening your doors, read the whole story at BestRide.com.


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