Price Modification Attack and Protection Scheme in Smart Grid

Smart grid addresses the problem of existing power grid's increasing complexity, growing demand, and requirement for greater reliability through two-way communication and automated residential load control among others. These features also make the smart grid a target for a number of cyber attacks. In this paper, we study the problem of price modification attack (PMA) through fabrication of price messages, which induces changes in load profiles of individual users and eventually causes major alteration in the load profile of the entire network. Combining with cascading failure, it ends up with a highly damaging attack. We prove that the problem is nondeterministic polynomial-time-complete and provide its inapproximability. We devise two approaches for the problem, the former deals with maximizing failure of lines with the given resource and then extending the effect with cascading failure, while the later takes cascading potential into account while choosing the lines to fail. We formulate new protection strategy against PMA and this includes two new algorithms, namely bi-level programming with new branching method and an effective heuristic to improve the running time. Empirical results on both IEEE bus data and real network help us evaluate our approaches under various settings of grid parameters.