Unhackable drones : the challenges of securely integrating unmanned aircraft into the national airspace

On August 2, 2010, a Navy helicopter entered the highly restricted airspace above Washington, D.C. without permission [1]. The event might have passed as unremarkable but for the fact that no-one was piloting the helicopter: as an unmanned aircraft, it carried no humans onboard, and—somehow—the vital communications link to its ground operators had been lost. The 1,429-kilogram MQ-8B Fire Scout flew entirely on its own for 30 minutes, blithely drifting through the airspace near nation’s capital [2, 3]. Ground operators at Naval Air Station Patuxent River in Maryland eventually regained control of the craft and ordered it to return to base, later diagnosing the cause of the unintended excursion as a “software issue.” But in fact more than one error had occurred: not only did the Fire Scout lose its communications link, it failed to execute its “return-to-base” lost-link protocol. So even as one Navy official put a good face on the incident by praising the reliability of the unmanned aircraft’s autopilot system [3], most saw it as a disconcerting example of the unresolved safety and security issues surrounding unmanned aircraft. The cost advantages of unmanned aircraft are compelling and will almost surely make these craft a component of everyday life in years to come. For the price of renting a human-piloted aircraft for a single power line inspection flight, a utility company could buy an entire unmanned aerial vehicle system to do the same job repeatedly. FedEx’s CEO and founder, Fredrick W. Smith, has talked about using drones to replace the company’s fleet of package-delivery aircraft [4]. For search and rescue, agriculture, infrastructure monitoring, research, and myriad other applications, unmanned aircraft—or drones in the common vernacular—provide convenience and economy. Recognizing this, the U.S. Congress passed the FAA Modernization and Reform Act in February 2012. The Act directs the FAA to draw up a “comprehensive plan to safely accelerate the integration of civil unmanned aircraft systems into the national airspace system” by 2015 setting the stage for broad drone use throughout the U.S. But there is a growing public backlash. Having witnessed drones employed primarily for surveillance and missile strikes in conflict areas outside the U.S., many see no good reason to welcome them into the U.S. national airspace. Who will be piloting these craft anyhow? Where and why? And with no human pilot onboard looking out the window, won’t they be more vulnerable to hijacking or hacking? Echoing the concerns of their constituents, lawmakers in over 42 states have proposed drone legislation imposing limits on unmanned aircraft use. For example, Texas House Bill No. 912 would make it a misdemeanor for a drone operator to