‘Relay Theft’ is the new method being used to steal cars. It makes use of the clever keyless enter and go technology that allows us to enter and start our vehicles without having to know exactly where the key is, just that it is close by.
This technology is loved by many drivers, if your hands are full or your handbag just seems to be bottomless your car will still magically open without the need to press any buttons.
This type of passive keyless entry was invented in 1995 and first launched on a mass-produced car by Mercedes-Benz. This type of key emits a signal that is recognised by receivers on the car.
Each key is programmed with a specific code to unlock only the car it is paired with. If the right code is received by the right car the doors will open and the engine can be started.
In a relay theft the signal from the key is captured by one of the thieves using a relay box. The relay box can detect the signal emitted from the key even through doors, windows and coat pockets.
Once this signal has been captured it can be sent to a second relay box which is being held by a second thief next to the car. This will trick the car into thinking the key is close by and the doors will open. This entire process can take as little at 60 seconds to complete and the relay boxes needed to
capture the key signal are readily available online and do not cost a lot of money.
Understandably, this has many car owners worried about whether they will wake up to an empty drive.
This security problem with our modern technology can be fixed by science from all the way back in 1836, the Faraday Cage. The Faraday cage has the ability to block signals emitted from the passive entry key. The box must be made of a material which is a conductor, most metals are good conductors.
Metal is made up of several different particles all bound together in an arrangement called a crystal lattice. One type of particle within this structure is an electron.
The electrons in a metal have the ability to move around freely, this is what makes metals such good conductors of electricity, as the electrons can move to carry the charge.
In the Faraday box the electrons respond to the signal from the car key by moving to one edge of the crystal lattice, effectively creating a shield of electrons. This shield prevents the signal from your key from leaving the box and so the car thieves will not be able to steal the signal or your new Mercedes.
Any vehicle with a passive keyless entry is potentially at risk from this type of attack. This type of keyless entry and go system is available on the majority of new cars and with the increase in popularity of vehicle leasing, there are many of these new cars on people’s drives to tempt the car relay thieves.
It will be interesting to see in the coming years how car manufacturers respond to this security threat and get one step ahead of the criminals once again.