FoxyTag

Another idea going round in my head is logging GPS data every second to the local file store, but the problem then is it could be used to incriminate yourself if obtained by police rather than used to get yourself off the hook if their equipment is faulty.

If the data is recorded and encrypted, in a lot of countries the police can demand you decrypt it, or put you in jail until you do.

An interesting problem I have no answer for at this point in time, no doubt some interesting application of plausable deniable cryptography.

The device would need a certification if we want to use it in order to prove that you where or not in specific place or if you were speeding or not. And, as you mentionned it, the laws vary a lot in the different countries. In Switzerland for instance, police forces are not allowed to arrest you in order to check what you have in your mobile phone. The must even have a good reason if they want to put their hand in your car (it is a private area)... In the US however, you cannot simply say "No thank you" if a policeman asks you something.

Foxy wrote:In the US however, you cannot simply say "No thank you" if a policeman asks you something.

Actually you can, they just have almost everyone bluffed into thinking they can't. A lawyer released a DVD + some you tube videos on how to deal with police at road stops and what your rights and so on are a while back.

As for device certification, a way round this would be a 3rd party hash signing service, you create a new file every 5 or 10 minutes and then make a hash of the file and get the hash signed, if the GPS time stamps are similar to the hash service time then there is a good chance it could be used similar to black box GPS devices that have been used in a similar way, the trick is to prove the evidence hasn't been tampered with.

delta_foxtrot wrote:Actually you can, they just have almost everyone bluffed into thinking they can't.

Nice to know.

delta_foxtrot wrote:As for device certification, a way round this would be a 3rd... ...evidence hasn't been tampered with.

Perhaps. But in European countries (at least France, Germany and Switzerland) a certification process would be necessary. Even for setting up a new fixed speed camera it is is very difficult and it needs a calibration time.

Foxy wrote:Perhaps. But in European countries (at least France, Germany and Switzerland) a certification process would be necessary. Even for setting up a new fixed speed camera it is is very difficult and it needs a calibration time.

I'm not familiar with European law, but the way most people would approach this is simply that speeding is a criminal offense in most countries that enforce it. So like most criminal rather than civil offences you only have to show reasonable doubt to be found innocent, you don't have to prove things conclusively that is the job of the police to find you guilty.