Foil defense: The simple trick to block car thieves' relay attacks

The "relay attack" method has become common in many countries like the United Kingdom. Edmund King, the leader of the British Automobile Association, recently urged drivers in the "Daily Mail" to be more cautious and better secure their car keys.

His wife fell victim to this method when her Lexus, worth $68,000, was stolen. How does it work? Thieves target cars with keyless entry systems. One of them approaches the door of a residence with a device that activates the key fob signal, which is then transmitted further.

The second thief near the vehicle uses a device resembling a suitcase, which receives the signal and relays it to the car. The car recognizes the signal as if the key fob were right next to the doors. This allows it to be opened and the engine to be started without the physical presence of the key fob.

Once the car is started, the key fob doesn’t need to be in the vehicle—it will drive until the engine is turned off. Thieves just have to deal with warning sounds and messages on the dashboard.

Research conducted by King shows that 51% of car owners with keyless entry do not use additional security measures. After the unfortunate incident, King keeps his keys in a signal-blocking case, which he places in a metal box, and that in turn goes into the microwave.

While such measures may seem excessive, it's worth taking certain security steps. You can buy special cases for keys online, which can be stored in a metal container or pot. The most important thing is to ensure the keys are not left near the doors. Edmund also recommends wrapping the key fob in aluminum foil. This is a cheap and simple way to protect your car from thieves. A few months ago, we tested how effective this method is, and the results can be found below.