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Here’s an intriguing puzzle: Some drivers are keeping a few pieces of aluminum foil by the front door. When they pull their car key fob out of their pocket, they wrap the foil around it and stow the entire thing on a shelf or counter for the night. No, the reflective layer isn’t to help them find their keys in the morning. This is a protective measure to keep their car from getting stolen.

Car thieves have developed a clever way to steal the most advanced cars. I’m talking about luxury models that have both keyless entry and keyless start, cars that only need you to have your key in your pocket to drive them away. Once thief waits by the car with a signal receiver/emitter. The other deploys an antenna by your door and captures the key fobs signal. By relaying the signals from both the key and the car, these two devices can make the vehicle think the key is nearby.

This car theft strategy is called a “relay attack.” While it’s been technically possible for years, the cost of the necessary equipment is going down while the range they can work at is going up. Worst of all, when thieves find a vulnerability in a certain make or model of car, they have been sharing it on social media. This results in certain “trending” vehicles being stolen.

Car thief looking through a window with a flashlight to prepare for a relay attack
Car thief | welcomia via iStockPhoto

So can wrapping your key fob in aluminum wrap…foil the thieves?

Puns aside, it could potentially work. Some experts I’ve read say you’ll really need multiple sheets of aluminum foil. And even then, all you’re doing is weakening the signal. But there are alternative methods that are a better bet.

Shutting down your car’s keyless entry feature–either for the night or indefinitely–is a sure way to thwart a relay attack. Note that if you have a key fob that requires you click a button to unlock your car, the relay attack won’t work.

If your automaker won’t let you disable this feature, the simplest solution is to move your key fob away from the door. But remember to move your spares as well. And finally, you can keep your key fob in a specially-build “”RFID blocker” pouch or box.

Next, read about the ‘Kia Boys’ who are showing TikTok users how to steal cars, or see a relay theft for yourself learn some ways to protect your keyless entry car in the video embedded below: