PPO & PPM 2.0: extending the privacy preference framework to provide finer-grained access control for the web of data

Web of Data applications provide users with the means to easily publish their personal information on the Web. However, this information is publicly accessible and users cannot control how to disclose their personal information. Protecting personal information is deemed important in use cases such as controlling access to sensitive personal information on the Social Semantic Web or even in Linked Open Government Data. The Privacy Preference Ontology (PPO) can be used to define fine-grained privacy preferences to control access to personal information and the Privacy Preference Manager (PPM) can be used to enforce such preferences to determine which specific parts of information can be granted access. However, PPO and PPM require further extensions to create more control when granting access to sensitive data; such as more flexible granularity for defining privacy preferences. In this paper, we (1) extend PPO with new classes and properties to define further fine-grained privacy preferences; (2) provide a new light-weight vocabulary, called the Privacy Preference Manager Ontology (PPMO), to define characteristics about privacy preference managers; and (3) present an extension to PPM to enable further control when publishing and sharing personal information based on the extended PPO and the new vocabulary PPMO. Moreover, the PPM is extended to provide filtering data over SPARQL endpoints.