How Relay Attacks Steal Keyless Cars — and How to Stop Them

Keyless entry is convenient — the car unlocks as you approach and starts at the push of a button because it senses the key nearby. That same convenience is the weakness thieves exploit, usually in under a minute and without damaging the car.

How a relay attack works

It typically takes two people and two cheap radio devices. One stands near your house with a receiver that picks up the faint signal from your key inside — on a hallway table, in a pocket by the door. That signal is relayed to a second device held next to the car, which fools the car into thinking the key is present. The doors open, the engine starts, and the car is driven away. No forced entry, no alarm.

The key never leaves your house — but as far as the car is concerned, it's standing right next to it.

How to stop it — cheaply

• Store your key in a signal-blocking (Faraday) pouch or tin. If the car can't hear the key, it can't be relayed. Test it: if the car doesn't unlock with the key in the pouch, it works.
• Keep keys away from the front of the house — the further from doors and windows, the weaker the signal a thief can grab.
• Turn off wireless key transmission if your car supports it (many keys sleep after a period of stillness, or can be disabled — check the manual).
• Add a visible deterrent: a steering-wheel lock or wheel clamp makes your car a slower, less attractive target.
• Lock the diagnostics: an OBD-port lock blocks a common method used to program a blank key.

If it happens anyway

Report the theft to the police immediately and list the vehicle in a public database the same day. Stolen cars are most recoverable in the first hours, while they're still on the road and passing public cameras. The faster your car is visible to buyers, spotters and anyone watching the main routes, the better your chances of seeing it again.