[whereis]

You'd think keyfob security would be worked out by now (just look at the prevalence of skeleton key software defined radios amongst the grayhat crowd). There's probably a limitation in security complexity due to limited power availability in the keyfob.

[WanderPanda]

How can that be an argument, when we can sign secure transactions using RFID?

[whereis]

Ah, cool. Sounds like there's no excuse. My mistake.

I mistakenly assumed you'd need some kind of cryptographic key signing handshake via active electronics from within the keyfob to achieve secure comms with the host vehicle, and that such a requirement may have been some kind of implementation limiting factor, security-wise.