[Cryptography] How to crypto secure speed limit signs

Henry Baker hbaker1 at pipeline.com
Wed Mar 25 09:39:18 EDT 2015

FYI -- In order to keep these Fords from being spoofed, we would need to "secure" each speed limit sign with a crypto signature.  Presumably, this could be done with a QR code. 

But how to avoid a "replay" attack -- i.e., cloning an existing sign & installing it somewhere else?  Should the QR code crypto sign the sign's GPS coordinates?  Wouldn't that make speed limit signs pretty expensive to manufacture & install?

Ditto with all kinds of other street signs.


Ford: Our latest car gizmo will starve you of fuel if you're speeding

Fighting automatic regulation with automatic adherence

Not as much fun as an angle-grinder to a gatso but a lot more legal

25 Mar 2015 at 08:55, Simon Rockman

Ford has announced a new intelligent speed limiter system which reads traffic signs and reduces fuel flow to keep your vehicle within the speed limit.

As much as the petrolhead lobby decries the direct correlation the road safety brigade makes between speed and safety, current legislation means that if you're driving too fast, regardless of how safely, you’ll usually get fined.

While a traffic officer can make a judgment call, ticket-bots won’t be quite so lenient. Now the Ford tech is fighting automatic regulation with automatic adherence.

The Intelligent Speed Limiter combines current Ford technologies: the Adjustable Speed Limiter and Traffic Sign Recognition, which are both already available on models including the Focus, Mondeo, and Kuga SUV.

At speeds of between 20mph and 120mph the system smoothly decelerates by restricting the fuel supplied to the engine, rather than applying the brakes. Should travelling downhill cause the vehicle to exceed the legislated speed an alarm is sounded.

The limiter also communicates with the on-board navigation system to help accurately maintain the appropriate maximum speed when distances between speed limit signs are greater, for example on long country roads.

Drivers can temporarily override the system by firmly depressing the accelerator pedal.

“We're not just developing cars at Ford, we're also developing technologies to make driving more convenient, safer, and ultimately help improve mobility around the world,” said Pim van der Jagt, executive technical leader, Ford Research & Advanced Engineering.

Maybe the first in line for this should be former Nokia boss Anssi Vanjoki who in 2002 was fined a massive €116,000 for doing 75km/h in a 50km/h zone on his Harley Davidson. In Finland traffic fines are proportionate to your income.

In 2013, 15,549 drivers in the UK were issued with fines of at least £100, according to the Department for Transport.

More details on the Ford website.


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