Combating time synchronization attack: A cross layer defense mechanism

A novel time synchronization attack (TSA) on wide area monitoring systems in smart grid has been identified recently. A cross layer detection mechanism is proposed to combat TSA in this paper. In the physical layer, we propose a G PS carrier carrier to noise ratio (C/No) based spoofing detection technique. In addition, a patch-monopole hybrid antenna is applied to receive GPS signal. By computing the standard deviation of the C/No difference from two GPS receivers, the a priori probability of spoofing detection is fed to the upper layer, where power system state is estimated and controlled. A trustworthiness based evaluation method is applied to identify the PMU being under TSA. Both the physical layer and upper layer algorithms are integrated to detect the TSA, thus forming a cross layer mechanism. Experiment is carried out to verify the effectiveness of the proposed TSA detection algorithm.