Assume you're getting downvoted instead of commented on because, as above poster pointed out, the weak point is the counter in any one-way scheme. Specifically

Assume you're getting downvoted instead of commented on because, as above poster pointed out, the weak point is the counter in any one-way scheme. Specifically when the car doesn't see a fob press but the fob is pressed (e.g. out of range / blocked). Thus, you have a broken keyfob if you ever press it outside the car's range (or require a "re-pairing" handshake to resynchronize the counters). Infeasible due to terrible usability. Or you widen the window of accepted counters to avoid the above issus. Which is what this attack is preying on.