ADS-B is used all over the world, the trend is actually in the opposite direction: more and more airspace requires the use of ADS-B. Encrypting it would defeat the purpose of allowing airplanes to see each other as well (ADS-B to some extent replaces radar).
Congress could presumably pass some law but it would have to be ICAO or some other global organization that would formalize the change. Updating the systems on all aircraft would take many years. The current roll-out has been in progress for more than a decade.
Congress could presumably pass some law but it would have to be ICAO or some other global organization that would formalize the change. Updating the systems on all aircraft would take many years. The current roll-out has been in progress for more than a decade.