[5by5]

I simply lack your faith in the infallibility of technology--regardless of the provider or implementer.

Much of the emphasis in aircraft design is in avoiding single point failure modes (no one thing, if it breaks, can jeopardize the integrity of the aircraft). Having a system that allows someone to take control from the ground (no matter how "secure") violates this time-tested design philosophy in a massive way.

Interesting thing about this approach is not only is it a single point of failure for any one aircraft but it may very well be a single point of failure for virtually every aircraft flying at any one time. Instead of 1-4 aircraft crashing, you can imagine *all* of them crashing at the same time if the remote control system is compromised.

Hypothetical question: Has an unbreakable encryption system ever been developed? The marketers might say "yes" but the cryptologists will always qualify their assertions with "not yet" or "it would be impossible with today's technology" or some such.

RE:

My post to you somehow disappeared; pardon me if this is a repost. 802.1X/RADIUS is a IETF network standard, it is not originated from Microsoft, but XP implements it. So do some network switches (Cisco). Routing control packets to the right tower along the flight path is, of course, no problem.

[annalex]

Pilotless flights would be indeed a single point of failure system, just like malicious access to the cockpit is a single point of failure today. However, implementing an ability to override the controls from the ground in an emergency, without routinely flying the planes solely from the ground would have prevented a 9/11 style attack. Since it won't be in everyday use, it can be made as secure as the famous "football" the president shleps around, that would trigger a nuclear war.