Assurance Cases for Security: The Metrics Challenge

For critical systems it is important to know whether the system is trustworthy and to be able to communicate, review and debate the level of trust achieved. In the safety domain, explicit Safety Cases are increasingly required by law, regulations and standards. Yet the need to understand risks is not just a safety issue and the type of argumentation used for safety cases is not specific to safety alone. Prior workshops, beginning with one held at DSN 2004, have identified a number of technical, policy and research challenges. The focus of this workshop is on one of these challenges: metrics for assurance cases for security.