Detection of Cyber-Attacks of Power Systems Through Benford's Law

This letter proposes an application of the Benford's law for the detection of cyber attacks in power system state estimators. Benford's law, also known as 1st-digit law, states an unexpected property of the distribution of the first digit of certain sets of data, and has been found to apply to a surprisingly wide range of data domains. The first novel contribution of the letter is to show that the Benford's law applies to power system data as well. A relevant property of this law is its high sensitivity to manipulations and, in fact, it is often utilized to detect frauds. Based on this feature, the second contribution of the letter is to utilize the Benford's law to detect malicious data introduced by hackers in the supervisory control and data acquisition (SCADA) system of a transmission network. Tests based on power system models ranging from 9 to 21,177 buses show promising results.