Relay Attack is a keyless theft method which is now responsible for up to 70% of all cases of vehicle theft.

While car makers’ technological advances have brought you greater convenience, they have also left your vehicle far more vulnerable to new theft methods. Using unregulated equipment bought easily and cheaply on-line, criminals can quickly bypass your car’s standard security.

It does not matter if your vehicle has a sophisticated factory fitted immobiliser and alarm, if its keyless entry, its vulnerable. The theft method known as relay attack is most often used to pick up your vehicle key’s signal from inside your house and then transmit or ‘relay’ that signal to your vehicle. Your vehicle is now fooled into thinking your actual key is present and in range. As such, all your factory fitted security is disarmed and the thief can gain entry, start, and drive away your vehicle, all in as little as 30 seconds.

Yes, your vehicle key’s signal is encrypted but the hardware and technology used to perform relay attack is designed to lengthen and copy your keys signal in real-time only once; to steal it from your driveway. In fact, once the thief has driven away your vehicle they’re unable to start it again. Why, because your vehicle’s key is still at your house. The only reason the thief was able to get away with your vehicle in the first place is because they had access to your vehicle key’s signal. The Relay Attack theft method copies your keys signal and encryption in real-time and then transmits it to your vehicle, effectively boosting or lengthening the range of your very short-range key (which is the source transmitting the signal the vehicle is listening for it to unlock).

Your vehicle key’s signal range is short, noticeably short. You will sometimes find even if you put the key on the passenger seat you may not be able to start the vehicle. The short range of your key’s signal is obviously designed to keep your vehicle secure when your away from it, such as inside your house. This limited range is what stops anyone from just opening your vehicle when the key is closeby. Your vehicles key always transmits a signal that your vehicle is listening for. The fact it is always transmitting is what thieves exploit as they then copy, boost and then relay this signal to your car using two transmitter/receivers.

Although we use the word ‘copy’ this is not factually true. The word ‘relay’ is important, important because thieves do not actually copy your key’s signal and store it, rather they pick up your key’s signal and encryption in real-time and relay it. Your key’s encryption prevents its custom signal from being stored and duplicated for use with another key or transmitted again at another time, it does not prevent the signal being picked up and relayed in real-time. This is how relay attack exploits keyless entry technology.

Some newer vehicle keys have built in motion sensors which switch off the key and stop it from transmitting after it has been sat idle for a period of time, this could be as long as 30 minutes which still leaves your vehicle vulnerable. Thieves do not just come to your home in the middle of the night to steal your keyless car. Such is the speed and success of relay attack; confident thieves are now using this method to steal vehicles in broad daylight and from busy public areas.

For instance, we recently fitted security to a past customers replacement vehicle, they had a vehicle stolen in London. The vehicle was parked just outside on the road, thieves used relay attack to pick up and relay/transmit their keys signal whilst they were queuing in the bank. They were able to get away with a £130,000 vehicle in a busy public place in broad daylight within seconds.

Having a vehicle stolen is incredibly stressful, especially when you consider the hassle of hire cars, insurance claims and increased insurance premiums, you could be looking at over a year before you even receive a replacement vehicle. We think that it is worth preventing your car from being taken in the first place with the installation of a No Tag, No Start system.

See our guide topic ‘Your Best Defence’ for more information on preventing keyless theft of your vehicle.