I mentioned the use of ADS-B technology in an earlier post on this thread, but didn't explain how I thought it could be used. Perhaps the presentation on Day 2 at 16.20 (ATSA-SURF - Enhanced situational awareness under adverse weather conditions) will help to explain what I mean:-
Joint Fifth ASAS-TN2 Workshop and Second FLYSAFE Forum ? ASAS TN
I know these are advanced concepts but I remain convinced that the display of other traffic using ADS-B In and Out, together with data linked warnings and taxi instructions will be the way forward as traffic levels rise and to help resolve mis-perceptions of the type that may have occurred at SFO
That presentation could be given today, given what was shown and what has been done. Sorry to say that was done in 2007, so in 10 years, nothing has happened.
ADSB signal consists of 112 bits, that is it, you barely get the root and the ac id in that, with coordinates, so forget about any encription, just not enough room. Even the other information is pretty granular.
ADSB may have use for ground movement, but in reality, you will never ever see ADSB-In on a commercial aircraft. Military has it, but it is built behind a very secure encryption system which is not available commercially.