Interdependent Security Game Design over Constrained Linear Influence Networks

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 security investments considering the network structure, costs and constraints, which have been set by the network owner. However, decisions of selfish entities to maximize their utilities do not always lead to a socially optimum solution. Therefore, motivating players to reach the social optimum is of high value from the network owner’s point of view. The network owner wants to maximize the overall network security by designing the game's parameters. As far as we know, there is no notable work in the context of linear influence networks to introduce appropriate game design for this purpose. This paper presents design methods that make use of the adjustments of players’ costs, interdependencies, and constraints to align players' incentives with a network-wide global objective. We present a comprehensive investigation of existence and uniqueness conditions of Nash Equilibrium in such environments. Furthermore, numerical results of applying the proposed mechanisms in a sample real-world example are illustrated.