>It is also trivial to be this attack by adding an accelerometer to the fob. If the fob isn't moving, don't respond to the broadcast from the car. You could als

>It is also trivial to be this attack by adding an accelerometer to the fob. If the fob isn't moving, don't respond to the broadcast from the car. You could also be more extreme and have the car check constantly. If fob disappears, kill the engine. That would have to be a pretty sensitive accelerometer but you'd still end up with voodoo stuff like "I have to shake my purse while starting the car". Killing the engine if the fob disappears means you need to be polling the fob. See the lawsuits over heavy keys wearing out the ignition lock and steering column locking up to see what happens when the polling fails. Probably not a good idea, IMHO.