The STREAM Mechanism for CPS Security The Case of the Smart Grid

Cyber-physical systems (CPSs) integrate computation, communication, and physical capabilities to interact with the physical world and humans. In this paper, we develop a novel strategic resource availability management (STREAM) system to improve information integrity and availability in an energy constrained CPS environment under the presence of malicious adversaries. The term “resource” here can be any component of a CPS. The main elements of STREAM are: 1) difficult but realistic “repeated (adversary-defender) game” settings and 2) a set of provably optimal defender strategies plus effective heuristics, against equally potent adversary moves. STREAM is based on the concept of dynamic games in sequential game theory, and is the first system to incorporate the realistic behavioral aspect that in many CPSs, both, the class of adversaries, as well as the class of CPS protectors, could move in a covert and stealthy manner in order to outwit the other in the war on “resource control.” In order to demonstrate the effectiveness of STREAM strategies to improve CPS resource availability to the nonadversary, we first conduct a thorough theoretical analysis on a model smart grid CPS as a representative example of a CPS. We then follow up the analysis with an extensive simulation study on the standard IEEE 14 smart power grid architecture. The results show that STREAM strategies improve smart grid system integrity and availability by approximately upto 67% when compared to nonstrategic approaches. Our proposed (analysis, simulation) suite for the grid is extendible to general CPS application domains.