In an interdependent world, the risks faced by any individual, firm, region, or country depend not only on its own choices but also on those of others. In the context of terrorism, the risks faced by any airline, for example, are tied to the security standards of other carriers and airports. To illustrate this point, consider the destruction of Pan Am flight 103 in 1988. In Malta, terrorists ch...

In today's highly interconnected networks, security of the entities are often interdependent. This means security decisions of the agents are not only influenced by their own costs and constraints, but also are affected by their neighbors’ decisions. Game theory provides a rich set of tools to analyze such influence networks. In the game model, players try to maximize their utilities through se...

We propose 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, a model due to Heal and Kunreuther that considers the source of the risk to be the result of a fixed randomizedstrategy. We adapt I...

In an interdependent world the risks faced by any one agent depend not only on its choices but also on those of all others. Expectations about others’ choices will influence investments in risk-management, and the outcome can be suboptimal for everyone. We model this as the Nash equilibrium of a game and give conditions for such a sub-optimal equilibrium to be tipped to an optimal one. We also ...

Even the most well-motivated models of information security have application limitations due to the inherent uncertainties involving risk. This paper exemplifies a formal mechanism for resolving this kind of uncertainty in interdependent security (IDS) scenarios. We focus on a single IDS model involving a computer network, and adapt the model to capture a notion that players have only a very ro...

Inspired by events ranging from 9/11 to the collapse of the accounting firm Arthur Andersen, economists Kunreuther and Heal [5] recently introduced an interesting game-theoretic model for problems of interdependent security (IDS), in which a large number of players must make individual investment decisions related to security — whether physical, financial, medical, or some other type — but in w...