Security and a Framework for Identity

We have a framework for a fundamental, hence broad, notion of identity, which allows very diverse and general aspects of security to be addressed. We use the causal theory of reference to explain how not just singular denoting expressions but also artifacts such as fingerprints and classifiers (broadly, “denoting devices”) denote individuals. Our current focus is on identity in criminal justice settings. The identity relation between denoting devices is an equivalence relation inducing equivalence classes that contain devices all of which denote the same individual. This is how information on individuals is typically fused. We see a case as a constellation of situations, to which investigators refer and in which information is recorded and transferred. We discuss how argumentation schemes support identity hypotheses, and how evidence for identity hypotheses from multiple sources is combined in Dempster-Shafer theory. Our framework can be applied in principle to any approach or technique for establishing identity hypotheses. The specific techniques of a domain (e.g., machine learning) are left to domain experts; we just incorporate them into our framework.