Abstract

There is no unified theory of privacy. Law, political science, economics, sociology and psychology have thoroughly explored the concepts of privacy, while computer science has attempted to apply these concepts with varying degrees of success. The study of privacy is often lost in a debate over values, whether privacy itself is a good thing or a bad thing, and how / when it may be reasonably invaded. This paper ignores that debate, reasoning that privacy is legislated so the values issue is no longer relevant, and proposes a theoretical mechanism for measuring privacy using trust as a model based on the need (briefly examined in Section 3) that knowledge about an individuals state of pri- vacy is necessary. Presenting 3 different sets of factors (human, computer and data) derived from multiple disciplines, this work identifies the list of considerations from which a state of privacy may be derived in any given situation; physical or virtual world. This work proposes an original model of the states of privacy based on the identifiability of an individual. Representation is a finite state machine, while the same list of factors can be used to calculate transitions in the machine.