>The basic summary of the proposal, known as Dedicated Short Range Communication (DSRC), is as follows. From the moment a car turns on and every tenth of a second until it shuts off, it will broadcast a so-called “basic safety message” (BSM) to within a minimum distance of 300m. The message will include position (with accuracy of 1.5m), speed, heading, acceleration, yaw rate, path history for the past 300m, predicted path curvature, steering wheel angle, car length and width rounded to 20cm precision, and a few other indicators. Each message will also include a temporary vehicle id (randomly generated and changed every five minutes), to enable receivers to tell whether they are hearing from the same car or from different cars.
Ok this could be useful, especially with autonomous vehicles hitting the road.
>Under the proposal, each message will be digitally signed. Each car will be provisioned with 20 certificates (and corresponding secret keys) per week, and will cycle through these certificates during the week, using each one for five minutes at a time. Certificates will be revocable; revocation is meant to guard against incorrect (malicious or erroneous) information in the broadcast messages, though there is no concrete proposal for how to detect such incorrect information.
Ugh, why do they need to be provisioned by a third party. Just let each car generate its own random ephemeral keypairs per some time interval and sign with those. You already said "Each message will also include a temporary vehicle id (randomly generated and changed every five minutes)", so what's the need for third party certificate provisioning.
They do work, but what if they could be cheaper and more effective?
A radio receiver is a cheap interface to implement and doesn't have the same line of sight requirements. Such a system would offer a bigger speed trap monitoring range, easier installation, and much more location flexibility.
Put one in every police vehicle. Get on a few interstate-adjacent radio towers. Roadside battery-powered installations that can easily be moved on a regular basis.
I wasn't trying to make a moral claim about the good/badness of speed traps. Just that a broadcast vehicle position system that allows the state to easily identify the vehicle will eventually be used for enforcing traffic law.
Comments
My thoughts:
>The basic summary of the proposal, known as Dedicated Short Range Communication (DSRC), is as follows. From the moment a car turns on and every tenth of a second until it shuts off, it will broadcast a so-called “basic safety message” (BSM) to within a minimum distance of 300m. The message will include position (with accuracy of 1.5m), speed, heading, acceleration, yaw rate, path history for the past 300m, predicted path curvature, steering wheel angle, car length and width rounded to 20cm precision, and a few other indicators. Each message will also include a temporary vehicle id (randomly generated and changed every five minutes), to enable receivers to tell whether they are hearing from the same car or from different cars.
Ok this could be useful, especially with autonomous vehicles hitting the road.
>Under the proposal, each message will be digitally signed. Each car will be provisioned with 20 certificates (and corresponding secret keys) per week, and will cycle through these certificates during the week, using each one for five minutes at a time. Certificates will be revocable; revocation is meant to guard against incorrect (malicious or erroneous) information in the broadcast messages, though there is no concrete proposal for how to detect such incorrect information.
Ugh, why do they need to be provisioned by a third party. Just let each car generate its own random ephemeral keypairs per some time interval and sign with those. You already said "Each message will also include a temporary vehicle id (randomly generated and changed every five minutes)", so what's the need for third party certificate provisioning.
Ugh, why do they need to be provisioned by a third party.
So the authorities know where to send the speeding tickets.
Traffic cameras, radar guns, and license plates already work pretty well for that.
They do work, but what if they could be cheaper and more effective?
A radio receiver is a cheap interface to implement and doesn't have the same line of sight requirements. Such a system would offer a bigger speed trap monitoring range, easier installation, and much more location flexibility.
Put one in every police vehicle. Get on a few interstate-adjacent radio towers. Roadside battery-powered installations that can easily be moved on a regular basis.
I wasn't trying to make a moral claim about the good/badness of speed traps. Just that a broadcast vehicle position system that allows the state to easily identify the vehicle will eventually be used for enforcing traffic law.