November 2, 2016
Commercially available drones can lose control or crash when exposed to radio frequency interference
By Elizabeth Droge-Young
Hobbyist drone sales are anticipated to reach 1.9 million units this year, according to the FAA. Recent work by Syracuse University computer engineering students and faculty points to a potential security vulnerability in these nearly 2 million machines: vulnerability to radio frequencies. The researchers hope their finding will lead to an electro magnetic interference (EMI) safety requirement in the drone certification process.
“You don’t want a drone flying 400 feet in the air to be shot with frequencies from a commercially available radio and suddenly drop on someone,” says Yuexin (Eric) Jiang, an undergraduate researcher in Professor Wenliang (Kevin) Du’s engineering security lab at Syracuse.
Using a lab-assembled drone, with parts purchased on Amazon or 3D printed at Syracuse University, Jiang discovered that the radio frequency produced by a ham radio would stop a quadcopter’s propellers from spinning or even crash the drone’s microprocessors in flight, this would spell a loss of flight control and could lead to a crash.
“The equipment we use is really simple. It cost $80 on Amazon for the radio and I operate it under my amateur radio license by making normal FM transmissions. We think this is something anyone could do—it doesn’t take specialized equipment to perform these attacks,” Jiang says, noting that they take precautions, including shielding the room they run experiments in, to prevent interference from leaving the room
Commercially available drones’ vulnerability could be a consequence of an unshielded signal wire, which is instrumental to the unit’s control. Du and Jiang suspect that the wire may act as an antenna and pick up RF energy in the environment, for example from a hobbyist’s ham radio. When this happens, the interfering radio energy may be flooding out the drone’s control signals on board, Jiang says.
While this initial, proof-of-concept exploration required Jiang’s radio to be physically close to a drone to disrupt the flight control components, he says that minor modifications could turn the radio into a long distance weapon. Using a directional antenna or pumping up the power in excess of what an amateur’s radio license allows would both increase the possible attack distance. While these actions would be illegal, they are possible to perform with commercially available components.
Jiang and Du explain that there is an easy fix: applying a radio frequency-impervious metal shield over the on-board controls. They suspect such a shield is routinely omitted from over-the-counter drones due to the manufacturing focus on producing lightweight machines.
“A lot of computers we use currently have shielding,” Du says. “It’s not that we don’t have the technology, we just forgot this basic safety principle.”
Jiang discovered the previously unidentified vulnerability to radio frequencies as part of a National Science Foundation-funded Research Experiences for Undergraduates (REU) project. A Korean group previously determined that sound waves from speakers could disrupt drones’ onboard control sensors, which got Jiang and Wu wondering what other wave types might be a threat.
The drone security investigation was spurred in part by Central New York’s receipt of the Upstate Revitalization Initiative award, a five-year, $500 million award from Gov. Andrew Cuomo’s office. One focal project of the initiative is drone research and development.
“Initially, our drone investigation began as a hobby, but when the initiative came in last December, we realized we could contribute,” Du says.
Jiang and Du hope that in response to their work the drone certification process will add shielding, or other EMI protections, like using differential signaling. “If you are selling a drone, you need to inform the user how vulnerable it is to EMI, and the consequences of that vulnerability,” Jiang says.
Their goal is simple: to make drones safer.