4 ms·
> After each keyfob button pressed the rolling codes synchronizing counter is increased. However, the vehicle receiver will accept a sliding window of codes, to
by buescher 4y ago
> After each keyfob button pressed the rolling codes synchronizing counter is increased. However, the vehicle receiver will accept a sliding window of codes, to avoid accidental key pressed by design. By sending the commands in a consecutive sequence to the Honda vehicles, it will be resynchronizing the counter. Once counter resynced, commands from the previous cycle of the counter worked again. Therefore, those commands can be used later to unlock the car at will.
Could the counter and clock resynchronization schemes in RFC 6238 "TOTP: Time-Based One-Time Password Algorithm" and RFC 4226 "HOTP: An HMAC-Based One-Time Password Algorithm" have similar bugs? In implementation if not in principle?