Test results are presented from GPS spoofing tests against Phasor Measurement Units (PMUs) to demonstrate their vulnerability to spoofing attacks. A GPS spoofer can manipulate the timing of a PMU by broadcasting a falsified GPS signal and forcing the time reference receiver that is providing timing for the PMU to track the falsified signal. This spoofer-induced timing offset creates a corresponding change in the phase angle measured by the PMU.

A particular synchrophasor-based automatic control scheme currently implemented in Mexico is described. It is shown that a generator trip could be falsely activated by a GPS spoofing attack in this system, thus highlighting the threat of spoofing a PMU. A description of the events that led to the 2003 northeast blackout is provided as an example of a potential worst case scenario where the legitimate or false tripping of a single generator or transmission line could lead to cascading faults and a large scale blackout.

Cite and download the paper:
D.P. Shepard, T.E. Humphreys, and A.A. Fansler, "Evaluation of the Vulnerability of Phasor Measurement Units to GPS Spoofing Attacks," Sixth Annual IFIP WG 11.10 International Conference on Critical Infrastructure Protection, Washington, DC, 2012.