Based on recently uncovered flaws in the satellite communications links in the USAF Global Hawk fleet, Northrop Grumman will modify the system to thwart potential hackers from disrupting or commandeering operations. The company will increase communications security in the International-Maritime-Satellite-enabled control links to the vehicle, which includes vehicle and ground systems
http://www.intelligent-aerospace.com/articles/2014/10/ia-globalhawk-cyber.html