"GPS Is Critical to Modern Life. It's Also Vulnerable, and This Researcher Is Out to Fix That."
The Global Positioning System (GPS) is inexpensive and easy to use because a device only needs to receive and interpret signals, not transmit, respond, or authenticate them. However, what makes GPS valuable also makes it so vulnerable, says Aanjhan Ranganathan, a professor at the Khoury College of Computer Sciences. Ranganathan received the National Science Foundation (NSF) Career Award for his research on GPS. Ranganathan explained that GPS is especially vulnerable to attacks due to its reliance on unsecured signals transmitted from satellites 20,000 kilometers above. By the time the signals reach the ground, they are already weak. $20 worth of equipment can render GPS devices incapable of receiving any signal. Alternatively, $100 worth of equipment can transmit signals that appear to originate from GPS satellites. This is known as "spoofing," in which a malicious actor fakes the source of a signal. Ranganathan tricked a drone into thinking it was somewhere it was not by spoofing the signals it was receiving. As he manipulated the GPS inputs, the drone drifted laterally to keep "standing still." The controller displayed no movement since the drone believed it was maintaining its position. Ranganathan successfully co-opted the drone without hacking it, bypassing its security protocols. The effects of spoofing are subtle and extensive. A malicious state could interfere with airplanes attempting to land, delaying flights. A cyber terrorist could steal military drones by making them land behind enemy lines. Due to the reliance of current timekeeping on GPS, a determined hacker could cost a bank billions of dollars by manipulating the timing of stock trades. This article continues to discuss the vulnerability of GPS to attacks and Ranganathan's research aimed at addressing this vulnerability.