I am not a hardware dev but I think this attack could be defeated by having the car measure the amount of time the key takes to respond to the call outs. If it takes more time than it should for the signal to travel a few feet, then it shouldn't unlock. If they embraced this method then existing cars could be protected with a software update instead of new hardware.
I think it could. For example, the Leica Disto2 laser rangefinder has a minimum measuring distance of 5cm. I don't see why an RF-based system couldn't do adequately for this use case.
Mr. Danev said his company was in talks with several car
manufacturers to install a chip that can tell how far the key
is from the car, thereby defeating the power-amplifier trick.
