A general defender-attacker risk model for networks

Purpose – The purpose of this paper is to present a competitive defender-attacker risk model that assumes a dual exponential relationship between defender (Ci) and attacker (Ai) resource allocation: vi(Ai,Ci)=e-aici-e-aiCi-?iAi. Design/methodology/approach – Network risk is defined in terms of degree sequence, g, node/link damage, d, and probability of failure, v:?R=?gividi. The paper finds the optimal allocation of resources (Ai, Ci) that minimizes R from the defender's point of view, and maximizes R from the attacker's point of view. Findings – The effectiveness of the optimal min-max strategy is compared with three allocation strategies: random, non-network, and network. It is shown that total network risk is minimized by the non-network strategy, because this strategy considers damage values and ignores network topology in the definition of risk. Originality/value – The method is illustrated by applying it to critical infrastructure – a hypothetical water-and-power network.