You can't rely on what other cars are telling you because a bad actor could create a device that sends out false information that leads to crashes (send out "I'm now accelerating from 50mph to 60mph" then brake immediately, or even just not accelerate and continue to go 50mph). You could of course solve this by verifying all the information sent by cars, but then you have negated any benefits because you have to be able to detect anything they could send in a message.
This argument doesn’t hold though because a single bad actor who figures out how to spoof the interface has tremendous leverage to hurt a lot of people at once. And it’s likely they could leave a device at night and trigger it days or weeks later. One instance of this could literally cause enough public fear to get AVs banned for years.
I agree with OP that each car managing its own cameras and radar makes the most sense. Cooperation by way of individual optimization is the cornerstone of modern society and something we should absolutely imbue our autonomous vehicles with.
>And it’s likely they could leave a device at night and trigger it days or weeks later.
same could be said about leaving a bomb on a bus, and yet there aren't bombs going off on busses every day, and even when it does happen, it's not enough to scare people away from busses for good.
Society kinda works because the vast majority of people are not homicidal.
" and yet there aren't bombs going off on busses every day, "
I don't know if that's true (except maybe in the literal sense that it's not every day, just frequently). As far as I'm aware this is a pretty big problem.
"Society kinda works because the vast majority of people are not homicidal."
I agree with this, and that self driving cars will only work under this assumption, but I don't think having vehicles communicate for safety-related (braking) information is the solution at all. If you're relying on that and can't get by with observed data alone, you open yourself up to a huge accident caused by a tiny rock or bird or anything unexpected (way more so than we do now).
If it's just supplementary as an extra layer of safety (attach this pod to your bike to make double sure all cars see you, but they're also still looking) then sure.
How come? As it stands, anyone can be a bad actor but their impact is limited, and it requires a pretty big sacrifice (their health). For example, nothing is stopping someone from driving the wrong way on the highway other than a couple of Do Not Enter signs, but by crashing their car into oncoming traffic they risk losing just as much as the people they crash into.
Cryptography just guarantees that the message hasn't been tampered with or read by a 3rd party, there's no way to mathmatically prove that you will accelerate
