4 ms·
Not sure if it was the case here, but apparently some cars can unlock automatically if the key is nearby. To hack this, you only need a sensitive receiver that
by gnaffle 13y ago
Not sure if it was the case here, but apparently some cars can unlock automatically if the key is nearby.
To hack this, you only need a sensitive receiver that can retransmit the signal from the key, and you need two people, on in proximity to the key, and another nearby the car when it unlocks.
- emidln 13y agoThat's not really the case. Some of them unlock via low frequency RF, but to my knowledge they still use encryption that uses their button click count as one of the variables plus a shared secret.
- gnaffle 13y agoYes, but the point of this scheme is that the car "believes" the key is in close range. If that is enough to get it to open the car, the thieves don't have to break any encryption, they just need to relay the RF signal. The faulty assumption on the part of the car manufacturers is that "RF signal present" equals "keyfob nearby".
- emidln 13y agoNo system I've been exposed to was defeated by a simple replay attack. You needed the shared secret and the click count (plus proprietary algorithm), which would be incorporated into the OTA message. Most LF systems are pretty low-bandwidth as well, and lock out quite quickly.
- gnaffle 13y agoTo clarify, I'm not talking about a replay attack. It's a _relay_ attack where they use the RF signal transmitted by the actualy car/key, just over a bigger distance than you would normally expect.