Evaluating goal ordering structures for testing harbour security policies

Large, complex systems can exhibit unforeseen behaviours. In the case of surveillance and security systems, these behaviours can be weaknesses that should be discovered by automated testing and ameliorated. Previous work has shown that such automated testing can be done using particle swarm optimization to learn behaviours that allow a set of attackers to defeat the system. However, for the optimization to succeed, it must have some knowledge about what constitutes a successful attack in order to guide the swarm. This knowledge is encapsulated in a goal ordering structure. In this paper, we examine the goal ordering structure and its role in the learning of system weakness. We specifically look at applications in harbour surveillance and security, and show how knowledge of the likely properties of a successful attack can be added to the goal ordering structure. Our experimental results show that adding knowledge to the goal ordering structure improves the search, when that knowledge is correctly inserted into the structure.