A security metric based on security arguments

Software security metrics that facilitate decision making at the enterprise design and operations levels are a topic of active research and debate. These metrics are desirable to support deployment decisions, upgrade decisions, and so on; however, no single metric or set of metrics is known to provide universally effective and appropriate measurements. Instead, engineers must choose, for each software system, what to measure, how and how much to measure, and must be able to justify the rationale for how these measurements are mapped to stakeholder security goals. An assurance argument for security (i.e., a security argument) provides comprehensive documentation of all evidence and rationales for justifying belief in a security claim about a software system. In this work, we motivate the need for security arguments to facilitate meaningful and comprehensive security metrics, and present a novel framework for assessing security arguments to generate and interpret security metrics.