Target-oriented utility theory for modeling the deterrent effects of counterterrorism

• We propose a target-oriented utility model for attacker deterrence.
• We model attack deterrence as a function of attacker success probability.
• We compare target-oriented utility model and conventional game-theoretical model.
• Results show that our model results better value of the defender’s objective function.
• Results support that defending series systems is more difficult than parallel systems.

Optimal resource allocation in security has been a significant challenge for critical infrastructure protection. Numerous studies use game theory as the method of choice, because of the fact that an attacker can often observe the defender’s investment in security and adapt his choice of strategies accordingly. However, most of these models do not explicitly consider deterrence, with the result that they may lead to wasted resources if less investment would be sufficient to deter an attack. In this paper, we assume that the defender is uncertain about the level of defensive investment that would deter an attack, and use the target-oriented utility to optimize the level of defensive investment, taking into account the probability of deterrence.