Short Paper: Detection of GPS Spoofing Attacks in Power Grids

Power companies are deploying a multitude of sensors to monitor the energy grid. Measurements at different loca-tions should be aligned in time to obtain the global state of the grid, and the industry therefore uses GPS as a com-mon clock source. However, these sensors are exposed to GPS time spoofing attacks that cause misaligned aggregated measurements, leading to inaccurate monitoring that affects power stability and line fault contingencies. In this paper, we analyze the resilience of phasor measurement sensors, which record voltages and currents, to GPS spoofing per-formed by an adversary external to the system. We propose a solution that leverages the characteristics of multiple sen-sors in the power grid to limit the feasibility of such attacks. In order to increase the robustness of wide-area power grid monitoring, we evaluate mechanisms that allow collabora-tion among GPS receivers to detect spoofing attacks. We apply multilateration techniques to allow a set of GPS re-ceivers to locate a false GPS signal source. Using simula-tions, we show that receivers sharing a local clock can locate nearby spoofing adversaries with sufficient confidence