Leave it to Toyota to take the simple and make it complicated. I don't know how Colin Chapman was able to have a partnership with them.So i spent a few hours with it, it's definitely some kind of handshake protocol because it isn't responding to any kind of playback attack.
Is this good or bad?
Also, holy crap is that bus chatty. there's a message every 2.8ms on average. That's a ridiculous amount of data to churn through.