Rational Choice of Security Measures Via Multi-parameter Attack Trees

摘要

We present a simple risk-analysis based method for studying the security of institutions against rational (gain-oriented) attacks. Our method uses a certain refined form of attack-trees that are used to estimate the cost and the success probability of attacks. We use elementary game theory to decide whether the system under protection is a realistic target for gain-oriented attackers. Attacks are considered unlikely if their cost is not worth their benefits for the attackers. We also show how to decide whether the investments into security are economically justified. We outline the new method and show how it can be used in practice by going through a realistic example.