Relations among privacy notions

Abstract

This article presents a hierarchy of privacy notions that covers multiple anonymity and unlinkability variants. The underlying definitions, which are based on the idea of indistinguishability between two worlds, provide new insights into the relation between, and the fundamental structure of, different privacy notions. We furthermore place previous privacy definitions concerning group signature, anonymous communication, and secret voting systems in the context of our hierarchy; this renders these traditionally disconnected notions comparable.