How wrapping keys in aluminum foil protects your car from thieves
Keyless systems are supposed to make driving more convenient. However, it is precisely this technology that has become one of the biggest safety risks in modern vehicles.
Criminals are increasingly using radio devices to extend car key signals and unlock vehicles without their owners realizing it. This method is particularly common at night and in parking lots.
The good news? A simple piece of aluminum foil can help protect your car from such attacks. Here’s how it works and what you can do.
How Keyless Car Theft Works
A smart key (also known as “Keyless Go” or “Passive Keyless Entry”) constantly transmits an RFID radio signal recognized by your car. As soon as the key is within range, you can unlock, enter and start the car without even taking the smart key out of your pocket.
This always-on RFID signal is what thieves intercept. Using a device called a relay, they can extend the permanent RFID signal so that it reaches your vehicle even when you are not near it.
Your car “believes” that its rightful owner is standing next to it, so the doors can unlock and the engine can start. Boom! Stolen.
How Aluminum Helps Foil Car Thieves
Aluminum reliably shields electromagnetic signals. Wrapping your car key in aluminum foil creates a kind of miniature Faraday cage that RFID waves cannot penetrate. The permanent RFID signal from the smart key can therefore no longer be intercepted by a relay device.
If your smart key is kept securely in aluminum foil or a metal container, your car will remain locked even if thieves are standing right outside the front door with their devices in hand.
Using the foil trick correctly
For the foil wrap trick to actually work, the foil wrapping needs to be tight and wrinkle-free. Two to three coats are usually enough. Here’s how to do it:
- Wrap the key completely in several layers of foil.
- Test it! If your car no longer opens, the insulation is working.
Alternatively, you can also place your smart key in a small box lined on the inside and covered on the outside with foil.
Is there a better solution?
Aluminum foil is a simple trick that works as an immediate stopgap measure. However, if you regularly park in densely populated areas, or if you park your vehicle on the street at night, or if you travel frequently, then you should consider a more permanent solution.
RFID blocking Faraday pouches are convenient, durable and protective. They are extremely affordable and come in different sizes to best fit your particular keychain. You can find them on Amazon for between $7 and $15, depending on the size and brand.
Security experts recommend never leaving smart car keys near doors or windows, as that’s where the signal is most easily intercepted. You should also check if your car’s passive keyless feature can be disabled. Some manufacturers offer corresponding options via the menu or a key combination.
Other smart car safety tips include:
- Park your vehicle in well-lit and visible areas.
- Use visible anti-theft devices such as claws on the steering wheel as an added deterrent.
- Check the behavior of your key regularly. A change in range may indicate malfunctions or technical problems.
