There is also no way to stop someone throwing rocks at passing cars. People will die as a result. The deterrents in both cases will be the same: humanity, liability and law enforcement.
Most of the people who will use malicious signals won't set out to actually hurt other people. They'll just use them to make tailgaters' cars brake quickly, or manipulate traffic in some way that benefits them, like the people in the late 80s or early 90s who figured out that putting strobe lights on their car roofs would let them make some city signals turn green for them. There are far, far more people who would be interested in that sort of thing than would be interested in the electronic equivalent of throwing rocks.
It's the unintended consequences that will generally kill people, like causing a multi-car pileup because the tailgater whose car was forced to brake was being tailgated themselves.
There will be very little way to enforce laws against that kind of activity, because there won't really be any forensic evidence at all.
There is no good way to do this. Even assuming a 100% flawless implementation of a "trusted enclave", people will just buy an ECU from a scrapped car, hook it up to a device that simulates the right sensor input to generate certain vehicle-to-vehicle communications, and stick it in the trunk of their actual car.
It's the unintended consequences that will generally kill people, like causing a multi-car pileup because the tailgater whose car was forced to brake was being tailgated themselves.
There will be very little way to enforce laws against that kind of activity, because there won't really be any forensic evidence at all.
There is no good way to do this. Even assuming a 100% flawless implementation of a "trusted enclave", people will just buy an ECU from a scrapped car, hook it up to a device that simulates the right sensor input to generate certain vehicle-to-vehicle communications, and stick it in the trunk of their actual car.