No key required: How thieves use relay boxes to steal cars

Getting in your car and starting it without having to pull the key out of your pocket is one of the small conveniences that come with many modern vehicles. Unfortunately, the capability is also convenient for car thieves.

As demonstrated in the above video, made available by the West Midlands Police, criminals equipped with relay boxes can unlock cars and drive away with them in under a minute.

How does a relay attack work?

Each of the thieves carries a relay box – a device that relays the signal from the car key to the car.

One attacker gets near enough to the key (in the house) to pick up the signal, relays it to the second box carried by the second criminal, who’s near enough to the car for the signal to be transmitted to it and trigger the unlocking. The criminals are then free to drive away in the stolen car, and to replace the locks at a later date.

In theory, all cars with keyless entry systems are vulnerable to the attack, but criminals have mostly been going after Audi, BMW, Ford, Hyundai, Land Rover, Mercedes and Volkswagen cars. Relay boxes can be bought online, sometimes even from eBay, for a relative pittance.

How to keep safe?

Keyless entry systems are convenient, but far from safe, and Mark Silvester, from the West Midlands Police crime reduction team, advised car owners to regularly update their car’s software, to keep their keys far from doors and windows, and to consider using a physical lock for the steering wheel and a tracking solution for the car.

The signal from the key can pass through walls, doors and windows, but is blocked by metal, so it might be a good idea for car owners to keep the key in a safe or any kind of metal box.