3 ms·

Not requiring an explicit (or at least conscious) action on the part of the user seems to be the flaw in the process. The countermeasures would appear to be:

Not requiring an explicit (or at least conscious) action on the part of the user seems to be the flaw in the process. The countermeasures would appear to be: * blocking the signal using some kind of Faraday cage to store your keys this relies on changing user behaviour, and not forgetting; kinda removes some of the “convenience” factor have some kind of disable switch on the key fob, in which case there’s not a huge difference to a regular remote lock/unlock button * expanding the range of frequencies the key fob uses to try and defeat the range extenders this likely has regulatory issues, and is probably easy to just update the hardware to cope with (if it doesn’t already) have the car do some kind of latency measurement on the challenge/response radio message exchange; given that light travels at 1ns per foot (ish!) the car will have to accurately and precisely measure only a few nanos difference, and not suddenly stop working because of nearby radio echoes in a concrete car park (or whatever) how close to the car is “convenient” to have it unlock automatically? 2 feet (driver standing by car)? 20 feet (kids running ahead to get into car)? * some kind of “parked up at home” mode so that the first unlock of the day requires a button push loses some of the convenience again got to remember to set it (some kind of car locking button again...) * you could have a second type of “anti-key” that you always leave at home, and when in range of this key the car won’t unlock keylessley easy target to block in the arms race or car theft easy to misunderstand as a user less convenience

matt-attack 9y ago
I had thought you offered a thorough exploration of the possible countermeasures, but you missed jgrahamc's suggestion below of adding an accelerometer to the fob. Only unlock when motion is detected. What are you thoughts? Seems that keys are incredible idle when sitting on the kitchen counter, and never perfectly idle when walking to approach your car.
- tomalpha 9y ago
  I think that’s a neat idea. In my defence, I might put that under the some-kind-of-switch-to-turn-it-off category but only in hindsight ;) Like latency-measurement though I wonder how robust it would be to the vagaries of modern life both in terms of reliability - potential moving parts - and in the face of user expectations - “I keep having to jiggle my keys to open my door” or worse, the dreaded “it doesn’t work!”. Where doesn’t work == doesn’t work how I think it should.

matt-attack 9y ago

I had thought you offered a thorough exploration of the possible countermeasures, but you missed jgrahamc's suggestion below of adding an accelerometer to the fob. Only unlock when motion is detected. What are you thoughts? Seems that keys are incredible idle when sitting on the kitchen counter, and never perfectly idle when walking to approach your car.

tomalpha 9y ago
I think that’s a neat idea. In my defence, I might put that under the some-kind-of-switch-to-turn-it-off category but only in hindsight ;) Like latency-measurement though I wonder how robust it would be to the vagaries of modern life both in terms of reliability - potential moving parts - and in the face of user expectations - “I keep having to jiggle my keys to open my door” or worse, the dreaded “it doesn’t work!”. Where doesn’t work == doesn’t work how I think it should.