Abstract
The Platform for Privacy Preferences (P3P), developed by the W3C, provides an XML-based language for websites to encode their data-collection and data-use practices in a machine-readable form. To fully deploy P3P in enterprise information systems and over the Web, a well-defined semantics for P3P policies is a must, which is lacking in the current P3P framework. Without a formal semantics, a P3P policy may be semantically inconsistent and may be interpreted and represented differently by different user agents; it is difficult to determine whether a P3P policy is indeed enforced by an enterprise; and privacy policies from different corporations cannot be formally compared before information exchange. In this paper, we propose a relational formal semantics for P3P policies, which precisely and intuitively models the relationships between different components of P3P statements (i.e., collected data items, purposes, recipients and retentions) during online information collection.The proposed formal semantics is an important step towards improving P3P, making it more appropriate to be integrated with business practice and ultimately accelerating the large-scale adoption of P3P across the Internet.
