Interdependent Security and Defense Games

Interdependent Security and Defense Games: From Airline Security to Vaccination and Cyber Defense


Attacks carried out by hackers and terrorists over the last few years have led to increased efforts by both government and the private sector to create and adopt mechanisms to prevent future attacks. This effort has yielded a more focused research attention to models, computational and otherwise, that facilitate and help to improve (homeland) security for both physical infrastructure and cyberspace. In particular, there has been quite a bit of recent research activity in the general area of game-theoretic models for terrorism settings.

The main objective of our project is to design models and algorithms to analyze networked multi-agent system's situations in which each agent is a node/vertex in some network being the source of a potentially deliberate attack by an external malicious agent. The internal network agent is an independent decision-maker assessing the cost-effectiveness of investments in defense or security that eliminates the effectiveness of direct-attack but can only diminish the effectiveness of catching indirect attacks via potential transfer from unprotected neighbors.

We proposed interdependent defense (IDD) games, a computational game-theoretic framework to study aspects of the interdependence of risk and security in multi-agent systems under deliberate external attacks. Our model builds upon Interdependent security (IDS) games. IDS applications include airline and port security, vaccination and cyber defense. IDS games consider the source of the risk to be the result of a fixed randomized-strategy.

We study computational questions in a modified version of the IDS game in which investing in security comes with some level of protection from transfers. More importantly, we adapted IDS games to model the attacker's deliberate behavior. It is important to note that the explicit modeling of risk transfer is an aspect of our model that has not been the focus of previous game-theoretic attacker-defender models of security.


Current Participants

Former Participant

Relevant Publications and Extended Abstracts

Software (Prototype)

Currently only available upon request


Currently only available upon request


Hau Chan was sponsored in large part by an NSF Graduate Research Fellowship (GRFP) Award. Luis E. Ortiz is partially sponsored by NSF.
National Science Foundation