ARMOR Software: A Game-Theoretic Approach to Airport Security

This paper describes how protecting national infrastructure such as airports, is a challenging task for police and security agencies around the world; a challenge that is exacerbated by the threat of terrorism. The protection of these important locations includes, but is not limited to, tasks such as monitoring all entrances or inbound roads and checking inbound traffic. However, limited resources imply that it is typically impossible to provide full security coverage at all times. Furthermore, adversaries can observe security arrangements over time and exploit any predictable patterns to their advantage. Randomizing schedules for patrolling, checking, or monitoring is thus an important tool in the police arsenal to avoid the vulnerability that comes with predictability. This paper focuses on a deployed software assistant agent that can aid police or other security agencies in randomizing their security schedules. At least three key challenges are faced in building such a software assistant. First, the assistant must provide quality guarantees in randomization by appropriately weighing the costs and benefits of the different options available. For example, if an attack on one part of an infrastructure will cause economic damage while an attack on another could potentially cost human lives, we must weigh the two options differently – giving higher weight (probability) to guarding the latter. Second, the assistant must address the uncertainty in information that security forces have about the adversary. Third, the assistant must enable a mixed-initiative interaction with potential users rather than dictating a schedule; the assistant may be unaware of users’ real-world constraints and hence users must be able to shape the schedule development.