  Many operations in power grids, such as fault detection and event location
estimation, depend on precise timing information. In this paper, a novel Time
Synchronization Attack (TSA) is proposed to attack the timing information in
smart grid. Since many applications in smart grid utilize synchronous
measurements and most of the measurement devices are equipped with global
positioning system (GPS) for precise timing, it is highly probable to attack
the measurement system by spoofing the GPS. The effectiveness of TSA is
demonstrated for three applications of phasor measurement unit (PMU) in smart
grid, namely transmission line fault detection, voltage stability monitoring
and event locationing. The validity of TSA is demonstrated by numerical
simulations.
