Enhancing P3P Framework through Policies and Trust

The Platform for Privacy Preferences (P3P) is a W3C standard that web sites can use to describe their privacy practices. The presence of P3P policies enables users to configure web browsers to constrain what they can and cannot do when visiting web sites. It's a good idea that unfortunately is rarely used. The authors identify two reasons for this: (i) the languages available to define a user's privacy preferences are not very expressive, and (ii) most web sites do not have published P3P policies. The authors propose enhancements to the P3P framework that uses Semantic Web technologies and models of trust. They use the Resource Description Framework (RDF)-based Rei policy language for more effective modeling of users' privacy-related constraints and preferences. Further, their approach is effective even in the absence of published P3P policies through the incorporation of their trust model. The authors present use cases to demonstrate the relevance of their work to the current web privacy landscape and offer it as a powerful enhancement that can promote P3P's adoption and use. Sponsored in part by the National Science Foundation under grants IIS0242403 and IIS0325172. The original document contains color images.