wrote:

Seems clear that tampering can be managed from outside the unit while
producing secure, valid record files

snip

If I can spoof the signal, can't I then create the file? With the
right set of tools and expertise (and an observer willing to cut some
corners), I could fly to 100,000 feet and circumnavigate the globe...
and deliver uncorrupted proof of my accomplishment. Getting people to
accept the proof then is just a matter of proportion.

That same log file included a barometric altitude trace. During the
period of interference it diverged from the gps altitude by an obvious
amount.

If you want to produce a valid igc file depicting a plausible world
record, you will have to do a lot of work to get a the time, barometric
altitude, gps altitude and gps co-ordinates to match with each other to
a standard where it will stand up to some scrutiny.

The sad thing is I think that this has just dealt a blow to those, who
like myself, who would like to see records from commercial grade GPS
equipment accepted for badge claims (especially silver and gold).


Ian