A team of "hackers" at the University of Texas.... with permission and oversight, I might add......has managed to pull a 65 meter ship off course by sending a fake navigational guidance signal to the ship.
The signal was increased in strength until it was primary to the ships systems...
The signal was unknown to the crew and drove the ship off course while the crew and onboard guidance system thought that the ship was on the correct course...
Obviously a very dangerous situation with huge consequences all around..
Could this be don't with an airliner?
I bet it could....
Could the plane conceivably be thrown off course or could the flight surfaces be compromised without the knowledge of the crew or systems.....
GPS commands and feedback is satellite "driven", right.....?
What say all of you?

 

GPS is a very weak signal (well a number of very weak signals, coming from different satellites). It would be very easy to jam, and possible to spoof. Nothing that is safety critical should use it as it's only method of navigation, but I'll bet that there are a few things that do.

 

Jamming is easy and while spoofing is a lot harder, it has been demonstrated by numerous teams.

In the 1996 FAA Radionavigation plan, they called for going to GPS as the sole means of navigation and phasing out ALL other systems (LORAN, VOR, TACAN, NDB, instrument approaches, you name it). That got a pretty strong reaction and they recinded that policy in 1997, but the last plan I checks (I think it was the 2011 0r 2012 plan) still has most of the enroute navigation systems, particularly VOR and TACAN, being allowed to die by attrition. It's a very stupid thing to do. GPS is wonderful -- and fragile.

INS (Intertial Navigation System) has gotten good enough and cheap enough that I think they could look at requiring all craft above a certain size and/or passenger count to have it and use it in an automatic cross checking mode. Even small UAV (hobby-scale) autopilots have GPS and INS in the same module, but they use the INS only as a stopgap for when the GPS signal isn't good enough to use. As long as the GPS signal is there, it accepts it on faith.

The work I did for my PhD was in jam resistant communication without shared secrets using concurrent code spread spectrum (CSCS), and civilian GPS would be an ideal application for it since, be definition, you can't have a shared secret because every human being on the planet is an authorized user. You are stuck with the near-far problem (jammer near, satellite far), but CSCS would give civilian GPS the same jam resistance as military GPS (which uses shared secrets). Unfortunately, it would be a disruptive technology and current receivers would not be able to interpret the new signals.