The practice of encasing automotive transponder keys in metallic foil, specifically aluminum, stems from concerns regarding radio frequency (RF) shielding. This involves creating a barrier that prevents electromagnetic signals from reaching or emanating from the key fob. An example would be a car owner enveloping their key in foil before entering their residence.
The importance of RF shielding lies in its potential to thwart relay attacks. These attacks involve criminals using signal amplification devices to intercept and re-transmit the key’s signal to the vehicle, effectively unlocking and starting it without the physical key. The benefit of foiling the key is to disrupt the signal transfer, rendering the relay attack ineffective. While the precise origin of this practice is difficult to pinpoint, its prevalence coincides with increased awareness of vulnerabilities in keyless entry systems and growing media coverage of vehicle theft through technological exploitation.
