Damon Lavrinc, for Jalopnik:
There are two kinds of keyless entry systems: The ones where you have to press a button on the key fob to unlock the door and the proximity-based systems that broadcasts a low frequency signal to recognize when the key is in your pocket, and then unlocks the doors when you’re close by or touch the door handle.
Bilton’s Prius had the latter, and that’s where the power amplifier comes into play:
Mr. Danev said that when the teenage girl turned on her device, it amplified the distance that the car can search, which then allowed my car to talk to my key, which happened to be sitting about 50 feet away, on the kitchen counter. And just like that, open sesame.
It’s a clever and simple hack, really. And I’ve just put two signal-blocking pouches on order.