Model-based evaluation of GPS spoofing attacks on power grid sensors

Emerging cyber-physical system (CPS) applications require reliable time synchronization to enable distributed control and sensing applications. However, time reference signals are vulnerable to attacks that could remain undetected for a long time. Sensor-rich distributed CPS such as the “smart grid” highly rely on GPS and similar time references for sub-station clock synchronization. The vulnerability of time synchronization protocols to spoofing attacks is a potential risk factor that may lead to falsified sensor readings and, at a larger scale, may become hazardous for system safety. This paper describes a simulation-based assessment of the effect of time accuracy on time-centric power system applications. In particular, the vulnerability of power grid sensors to erroneous time references and the potential risks of time-base spoofing on power grid health are studied, using the Ptolemy modeling and simulation tool. Both the false alarm and the missed generation scenarios are considered, where the GPS spoofer may lead the substation to declare an erroneous out-of-phase situation, or the substation may be disabled to detect anomalies that are present in the incoming phase data.