Stolen cell phones wrapped in aluminum foil: a Faraday cage vulnerable to leaks

The theft of smartphones It has been perfected with the use of a product commonly used in kitchens, aluminum foilwhich allows the creation of a Faraday cage that prevents the device from being geolocatable, although this rudimentary technique is not foolproof.

“Aluminum foil can leave a mobile phone practically mute,” Panda Security’s global consumer operations manager, Hervé Lambert, confirmed to Europa Press. “It’s basic physics. Aluminum conducts electricity and, when completely wrapped, the device acts as a rudimentary Faraday cage that dims or blocks mobile network, GPS, WiFi and Bluetooth“.

The Faraday cage refers to a protective metal box with the capacity to block electromagnetic signalswhich was invented in 1836 by British scientist Michael Faraday. An example of this today is the microwave.

This homemade way of preventing smartphones from transmitting signals has become known following the celebration of the eighth edition of the Pirata Beach Festival, in Gandía, after the Police Intervention Unit identify a person with a dozen cell phones wrapped in aluminum foilas reported by the newspaper Levante.

However, Lambert explains that, although effective, a cage made with this material it is not infallible: “An opening, a poorly made fold or a single layer can allow leaks, especially in areas with good coverage,” he says.

It also does not destroy the location systemwhich means that “as soon as the thief removes the packaging, opens the bag, turns on the device, or the shield fails, the device can reconnect and execute pending orders.”

Faced with the possibility of recovering the stolen mobile phone, the cybersecurity expert indicates that what needs to be done is report the theft to the authorities with the IMEI number, block the phone’s SIM or eSIM card and keep the Google or Apple account, because this hinders its resale and enables protections such as activation lock.

“Aluminum foil can buy the criminal time, but It can also work against you as soon as the mobile starts broadcasting again.“Lambert added.