Cyber-Physical Systems for Resilient Infrastructures

IDSS PIs: Hamsa Balakrishnan, Asu Ozdaglar
Collaborator: Saurabh Amin

When IT networks interface with infrastructures such as water and electric systems to provide monitoring and control capabilities, they often introduce new vulnerabilities that increase the risks of service disruptions. The Foundations of Resilient Cyber-Physical Systems (FORCES) project aims to improve CPS technology. Read more about the Resilient Infrastructure Networks Lab.

This research examines security decisions of identical plant-controller systems, when their security is interdependent due to network induced risks. Each plant is modeled by a discrete-time stochastic linear system, with the systems controlled over a shared communication network. Researchers formulated the problem of security choices of the individual system operators (also called players) as a non-cooperative game. They considered a two-stage game, in which on the first stage the players decide whether to invest in security or not; and on the second stage, they applied control inputs to minimize the average operational costs. They characterized the equilibria of the game, which includes the determination of the individually optimal security levels. Next, the solved the problem of finding the socially optimal security levels. The presence of interdependent security causes a negative externality, and the individual players tend to under invest in security relative to the social optimum. This leads to a gap between the individual and the socially optimal security levels for a wide range of security costs. From our results, regulatory impositions to incentivize higher security investments are desirable.

References and Related Content:
“Protecting infrastructure with smarter CPS” – MIT News, Sept. 2014

“Security of interdependent and identical networked control systems” – Automatica

“In quest of benchmarking security risks to cyber-physical systems” – Network, IEEE