Yo Max,

Chill dude. Paul was simply restating the long-held position espoused by the IGC's GFAC.

A committed enough cheater could defeat any of the current security features of IGC FRs; though many of them would require some significant level of complicity by an OO.

What everyone who pushed for GPS Position Recorders was looking for was/is a level of security that makes it impossible for a "casual" modification of a log file by a pilot who needs to eliminate one or two pesky fixes that "accidentally" put him/her into prohibited airspace or to slide a couple of fixes a half kilometer in one direction or the other to take care of a missed OZ. As long as the hardware/software combination is reasonably protected from this sort of casual hacking, NACs may (or may not) choose to promote devices as GPS Position Recorders.

Erik Mann

On Friday, August 16, 2013 9:25:23 AM UTC-4, Max Kellermann wrote:
On Friday, August 16, 2013 1:39:23 PM UTC+2, Paul Remde wrote:

They don't trust PDA/PNA devices because they

think someone could write software to intercept and change the GPS data

before it is recorded. I don't agree with them on this, but that is I

understand their position.



You don't agree that somebody could write a software to fake GPS positions? Seriously?



It's a technical fact that this can be done, and it's fairly easy. I do it all the time while I develop XCSoar, to test the software I write.



Your personal opinion on this is provably wrong. Stuff like that cannot be decided by consensus or personal opinion - if it's technically doable, no opinion can ever make it impossible.



(With some more effort, all loggers, even sealed ones, can be spoofed, without ever touching the logger - this has been demonstrated last week by the University of Texas. Never say never.)