4 ms·

What about adding signed QR codes to road signs? It's practically impossible to forge those, it doesnt't require complex vision systems, and you don't have to r

by kgeist 5y ago

What about adding signed QR codes to road signs? It's practically impossible to forge those, it doesnt't require complex vision systems, and you don't have to revamp your whole road infrastucture, just gradually replace existing signs.

ragebol 5y ago
The reason for reading the existing traffic signs is that they already exist. If you would design roads for autonomous cars, you'd replace the signs with eg. radio beacons and the like.
- mnd999 5y ago
  Let’s do that - on highways where it’s worth the investment. And let’s stop pretending that self-driving is in any way viable on normal roads. Outside of that relatively controlled environment, there are too many inputs and the reasoning requires is too complex.
- delusional 5y ago
  I think you'd agree that putting QR codes on signs is cheaper and less intrusive than replacing them with radio beacons.
  - ragebol 5y ago
    I do agree that is would be cheaper, but they're ugly and quite intrusive as I can't read them.
    - BoxOfRain 5y ago
      Yeah I don't know what it is about QR codes but I'm really not a fan of the aesthetic they have. There's something cheap, mechanistic, institutional about them that I can't quite put my finger on.
asah 5y ago
clever! and it reuses the existing (low) tech of painted signage.
teddyh 5y ago
They would have to be signed including GPS coordinates, otherwise they would be vulnerable to a replay attack. And since GPS is not that precise, you would still be able to, say, take two nearby signs and switch them.
- Freak_NL 5y ago
  And of course the obvious problem of how you would keep the signing key private over time. Road signs are made by many companies working for every level of government from the national level down to individual municipalities. Centralise the generation of QR-codes? Great single point of failure there, and now any sign placed temporarily because of unforeseen events (flooding, bridge collapse, etc.) won't be acknowledged by the autonomous car because it lacks a valid QR-code.
  - jjk166 5y ago
    The QR code is just a hash of the information on the sign to confirm that the system is reading the sign correctly. If someone actually puts up an incorrect sign, it would be immediately apparent to humans. If you really wanted a secure system you'd just have a database of all the signs in an area that cars could access (for example if I know what road i'm on, and my approximate location on that road, I should be able to look up what the speed limit on this stretch of road is). The fact is if you want to be able to stop a car from going over a bridge that's collapsed by placing a sign in front of it, inevitably the same system can prevent a car from going over a bridge that hasn't collapsed. Realistically, unexpected road signs should prompt manual operation.
todd8 5y ago
> It's practically impossible to forge those,... Forging isn't necessary, just copying one that is inappropriate in a particular setting. Forgery isn't difficult either if the QR code isn't signed. QR codes are standardized and software to generate any QR code is reasonably straightforward to write (one has to know a bit about Reed-Solomon error correction), but writing software isn't necessary because there are a number of easily available libraries that can be used to generate QR codes. Cryptographically signed QR codes (which I believe are what you are talking about) would need to include location data that could be verified by the vehicle, such as GPS coordinates and the sign's facing direction. This might work, but of course the logistics could be difficult in practice. Since signs aren't on the internet, it would be impossible to update them whenever a signing key was compromised. Key compromises would probably happen because signs are manufactured all over the world.

by kgeist 5y ago

ragebol 5y ago

The reason for reading the existing traffic signs is that they already exist. If you would design roads for autonomous cars, you'd replace the signs with eg. radio beacons and the like.

mnd999 5y ago
Let’s do that - on highways where it’s worth the investment. And let’s stop pretending that self-driving is in any way viable on normal roads. Outside of that relatively controlled environment, there are too many inputs and the reasoning requires is too complex.
delusional 5y ago
I think you'd agree that putting QR codes on signs is cheaper and less intrusive than replacing them with radio beacons.
- ragebol 5y ago
  I do agree that is would be cheaper, but they're ugly and quite intrusive as I can't read them.
  - BoxOfRain 5y ago
    Yeah I don't know what it is about QR codes but I'm really not a fan of the aesthetic they have. There's something cheap, mechanistic, institutional about them that I can't quite put my finger on.

asah 5y ago

clever! and it reuses the existing (low) tech of painted signage.

teddyh 5y ago

They would have to be signed including GPS coordinates, otherwise they would be vulnerable to a replay attack. And since GPS is not that precise, you would still be able to, say, take two nearby signs and switch them.

Freak_NL 5y ago
And of course the obvious problem of how you would keep the signing key private over time. Road signs are made by many companies working for every level of government from the national level down to individual municipalities. Centralise the generation of QR-codes? Great single point of failure there, and now any sign placed temporarily because of unforeseen events (flooding, bridge collapse, etc.) won't be acknowledged by the autonomous car because it lacks a valid QR-code.
- jjk166 5y ago
  The QR code is just a hash of the information on the sign to confirm that the system is reading the sign correctly. If someone actually puts up an incorrect sign, it would be immediately apparent to humans. If you really wanted a secure system you'd just have a database of all the signs in an area that cars could access (for example if I know what road i'm on, and my approximate location on that road, I should be able to look up what the speed limit on this stretch of road is). The fact is if you want to be able to stop a car from going over a bridge that's collapsed by placing a sign in front of it, inevitably the same system can prevent a car from going over a bridge that hasn't collapsed. Realistically, unexpected road signs should prompt manual operation.

todd8 5y ago

> It's practically impossible to forge those,... Forging isn't necessary, just copying one that is inappropriate in a particular setting. Forgery isn't difficult either if the QR code isn't signed. QR codes are standardized and software to generate any QR code is reasonably straightforward to write (one has to know a bit about Reed-Solomon error correction), but writing software isn't necessary because there are a number of easily available libraries that can be used to generate QR codes. Cryptographically signed QR codes (which I believe are what you are talking about) would need to include location data that could be verified by the vehicle, such as GPS coordinates and the sign's facing direction. This might work, but of course the logistics could be difficult in practice. Since signs aren't on the internet, it would be impossible to update them whenever a signing key was compromised. Key compromises would probably happen because signs are manufactured all over the world.