A Privacy Preference Ontology (PPO) for Linked Data

Linked Data enables people to access other users’ data stored in several places, distributed across theWeb. Current Linked Data mechanisms mostly provide an open environment where all data is freely accessible, which could discourage some people to provide sensitive data in the Linking Open Data (LOD) cloud. Although the existing Web Access Control (WAC) vocabulary restricts RDF documents to specified users, it does not provide fine-grained privacy measures which specify complex restrictions to access the data. In this paper, we propose a lightweight vocabulary — on top of WAC — called the Privacy Preference Ontology (PPO) that enables users to create fine-grained privacy preferences for their data. The vocabulary is designed to restrict any resource to certain attributes which a requester must satisfy.