>Modern cars are protected against thefts by using a smart key that talks to the car and exchanges cryptographic messages so that the key proves to the car that it’s genuine. [...] The thieves found a simple way around this: they used a hand-held radio relay station that beams the car’s message into the home to where the keys are kept, and then relays the message from the keys back to the car. The car accepts the relayed message as valid because it is - the real keys were used to unlock the car. Now that people know how a relay attack works generally possible to defeat it: car owners keep their keys in a metal box
? The car talking to the key first? Can't the key just not talk to the car at all unless the button is pressed on the key fob or shortly thereafter?
A lot of cars in the 2010s made available touch-based convenience access. ie if I have the fob on my person, the car unlocks when I touch the handle of a door, or gesture to open the trunk.
In the 2020s, I’m increasingly seeing smartphone (NFC?) keys being the sole thing you need to drive off with the thing so no fob is even necessary.
Or bluetooth. I'd rather have a pocket fob than have to take my phone out and hold it up to an NFC reader.
The problem with the bluetooth method is reliability. My Tesla decides not to unlock for me perhaps once every 20 times I walk up to it. Sometimes just a few seconds while it figures it out, sometimes I have to open the up and hit the door unlock button.
My wife's Bolt uses a pocket fob, and so far it has never refused to unlock the doors on command.
This also happened (happens) to me and my 2020 Model Y. When I first purchased the car I had a Google Pixel 4 (I think) and now I have an iPhone 13 running the latest iOS. My car still doesn't unlock right away about 1 out of 20 times I walk up to it. It's not really a big deal as the car usually unlocks shortly after arriving but it is kind of a pain if my hands are full and I have to fumble with my phone to "manually" unlock it.
iPhone running iOS 16.4. This is something I've experienced for years, since I bought my first Model 3 in 2019. I don't think it has much to do with the phone or the OS revision.
That's sort of how it works. The car "wakes" the key up to auth with it when you touch the switch on the door. The relay attack is bidirectional so it replays both the wake up from car to key and the response from key to car.
? The car talking to the key first? Can't the key just not talk to the car at all unless the button is pressed on the key fob or shortly thereafter?