What is a 'car relay' attack?

A car relay attack is a type of cyber-attack where thieves exploit the wireless communication between a car's key fob and its ignition system.

Modern cars often use keyless entry and ignition systems that rely on short-range radio signals to unlock and start the vehicle.

In a relay attack, criminals use two devices: one positioned near the car and the other near the key fob. These devices capture and relay the key fob's signal to the car, tricking it into thinking the key is nearby and allowing the thieves to unlock and start the vehicle without the owner's key.

The process begins when the first relay device, placed close to the car owner's house or location where the key fob is kept, picks up the signal emitted by the key fob. This signal is then transmitted to the second relay device near the car, which sends the captured signal to the vehicle. The car receives this signal as if the key fob were in proximity, unlocking the doors and enabling the ignition system. This sophisticated yet straightforward technique allows thieves to steal a car in minutes without physically breaking into it.

One of the reasons car relay attacks are particularly concerning is their ease of execution. Thieves do not need to hack complex systems or have in-depth technical knowledge; they only need to acquire relatively inexpensive relay devices, which can be easily found online. Additionally, the attack can be executed quickly and silently, often without arousing suspicion until the car is already gone. The stealthy nature of these attacks makes them a growing threat, particularly in urban areas where cars are parked in close proximity to their owners' homes.

To protect against relay attacks, car owners can take several precautions.