Combination of D-AHP and Grey Theory for the Assessment of the Information Security Risks of Smart Grids

As a modern power infrastructure, smart grids have great advantages over traditional power grids, but their effective operation is largely restricted by information security. Hence, a smart grid information security risk assessment (ISRA) method is proposed. This method combines D numbers to improve the classical analytic hierarchy process (D-AHP) independent of experts’ subjective qualitative assessment and then integrated with grey theory which does not require complete and unambiguous information. First, we establish a smart grid ISRA system according to the characteristics and development reality of smart grid technology. The proposed system includes 5 first-level indexes as an intelligent terminal, a wireless communication channel, password security, application code and embedded system, and corresponding 13 secondary indexes. Second, a D-AHP method aimed at the uncertainty of human subjective judgment and fuzziness of language assessment is used to obtain the weight of each index. The D-AHP method is then combined with the grey assessment matrix solved by grey theory, to obtain the comprehensive assessment value and corresponding risk grade. With a smart grid demonstration project in Suzhou, China, as an example, an empirical study is carried out using expert scoring. The comprehensive assessment risk value is 3.8199, and the corresponding risk level is moderate. The results of this work could serve as a reference for the information security protection of smart grids.