3 ms·
Why aren't the previous codes invalidated though? If the attacker catches code X, and the owner presses the button again to send code X+1, why is code X still v
by lucaspiller 9y ago
Why aren't the previous codes invalidated though? If the attacker catches code X, and the owner presses the button again to send code X+1, why is code X still valid?
- lunixbochs 9y agoBoth X and X+1 are jammed, then the attacker replays X. The car never sees X+1 to revoke either.
- ipunchghosts 9y agoYes. There is a rolling code both inside your car rx and the fob tx. They get out of sync (think of pushing your car unlock when your car is not around) but the fob can never be behind the car. By jamming the the rx at the car it never gets code X+1 but the attacker does so the car never rolls ahead. Then, the attacker replays X+1 and the car unlocks. This attack has been known for a quite a long time along with the TPMS hack (made famous but rutgers and U South Carolina http://www.sc.edu/news/newsarticle.php?nid=1202#.WRXDdVXythE http://www.sc.edu/news/newsarticle.php?nid=1202#.WRXDdVXythE) https://www.theregister.co.uk/2010/09/21/car_jammer_vehicle_theft_scam/ https://www.theregister.co.uk/2010/09/21/car_jammer_vehicle_...