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Modern cars with keyless entry and push-button start offer great convenience. Drivers can unlock the doors and start the engine without taking the key out of their pocket.
However, these systems rely on a radio signal transmitted by the key fob. If the key is left near a front door, window, or exterior wall, thieves may be able to capture and extend that signal using electronic devices.
In a typical relay attack, two criminals work together. One stands near the house with a device that detects the key fob’s signal, while the other waits near the vehicle with another device that relays the captured signal. This tricks the car into believing the key is nearby, allowing it to unlock—and, in some cases, start.
Why the microwave can block the key signal
The reason some people store their car keys in a microwave is that its metal enclosure can act as a shield, reducing or blocking the radio signals emitted by the key fob.
When the microwave is turned off, it may function similarly to a Faraday cage, making it much harder for thieves to intercept the signal.
Important: Never switch on the microwave while the keys are inside. Doing so could damage the electronics in the key fob and may also damage the microwave.