Automotive security experts are renewing their campaign to educate vehicle owners about the simple and inexpensive protection offered by Faraday cage pouches against key fob relay theft, a theft method that has become the dominant technique for stealing modern keyless entry vehicles. The relay attack works by using two devices to amplify the signal from a key fob left inside a home, fooling the vehicle into thinking the key is nearby and allowing the doors to unlock and the engine to start. A Faraday pouch or even a metal tin is sufficient to block the signal and defeat this attack entirely.
Despite years of coverage of this theft technique and the straightforward nature of the countermeasure, surveys consistently find that most keyless entry vehicle owners are still unaware of the relay attack risk and are not taking the simple precaution of shielding their key fobs when not in use. The cost of a quality Faraday pouch is typically under twenty dollars — a trivial expense relative to the value of the vehicle being protected. Manufacturers have been slow to integrate hardware fixes into new vehicles, making the pouch the most reliable protection currently available to the large installed base of vulnerable keyless entry vehicles.