Keyless car theft prevention: how relay attacks work and police chief’s tips on how to stop keyless theft

Drivers whose cars use keyless entry systems are being urged to take steps to protect themselves from criminal gangs targeting the technology.

The contactless entry and start function is convenient for drivers who don't want to dig around for their keys but also provides a relatively quick and easy way for crooks to steal high-value modern cars. Police have blamed a rise in thefts in part on thieves exploiting the technology and figures from the Office of National Statistics show that keyless entry was the most common method of access for vehicle thefts in England and Wales in 2020, used in 36% of all cases.

Recent insurance data from Aviva also shows that between 2020 and 2022, drivers whose cars featured keyless systems were twice as likely to make a claim for vehicle theft than other customers, prompting police to urge motorists to take extra precautions.

Assistant Chief Constable Jenny Sims, lead for vehicle crime at the National Police Chiefs’ Council (NPCC), said: “Whilst the rapid development of technology has dramatically improved the experience of drivers it has also allowed criminals to exploit weaknesses in electronic security. We are working closely with car manufacturers to help them design out crime by sharing intelligence and equipment seized from criminals. We are already making substantial progress in this regard.

“I would urge drivers to take simple steps to keep their vehicle safe like storing your keys in metal tins or protective pouches that block the devices criminals are using. A return to basics like making sure your car is locked is worthwhile too. We know from research that some owners think that cars automatically lock – they don’t. Always double check before you walk away that it’s locked.”

How keyless entry car theft works

Relay attacks work by fooling a car’s security system into believing the key fob is present. Thieves use a receiver/transmitter to intercept the unique signal from the key fob, even through house walls. This is then relayed to another receiver/transmitter held near the car, which allows it to be unlocked and started.

The process can take just a few seconds and means crooks can open and drive away a car without activating any alarm. Some brands, including Ford and Land Rover have developed key fob technology that helps protect against relay attacks and retailers have reportedly seen an unlift in sales of old-fashioned deterrents such as steering locks, but there are other steps any driver can take to reduce the risk of falling victim.

How to prevent keyless theft

The technology behind keyless entry and start may be complex but there are simple steps to stop the systems’ vulnerability from being exploited.

• Store your key fob away from household entry points. The further they are from the house exterior, the harder it is for crooks to pick up the signal.
• Invest in a Faraday pouch. These are cheap fabric pouches lined with a metal mesh that blocks the fob’s signal. An alternative is to pop the keys in a lidded metal tin, such as a biscuit tin, which has the same effect.
• Speak to your dealer. Some cars’ systems can be deactivated and some models will have received software updates that can improve security, so make sure your vehicle is up to date. Some manufacturers, such as Ford, have also developed new fobs that automatically power down to stop relay attacks. Ask if this is available for your car.
• If you have a garage, use it. A car locked up out of sight is a far less tempting target for thieves.
• Buy a steering lock or pedal box. These old-fashioned security measures have made a comeback in recent years as a simple physical obstacle that makes the car impossible to drive even if criminals can get the engine started.
• You should also always check your car is locked before you leave it. Stealing a car via relay or any other attack is much easier if the car isn’t locked in the first place.
• Park in a well-lit area. According to the Met Police, vehicles parked in dark and less busy areas are more likely to be broken into and damaged. It is therefore recommended to park in well-lit and busier areas if you don’t have a private garage or driveway - and when away from home.