Secured Semantic Web Applications

The Semantic Web has been envisioned as a structure that is machine interpretable where different data instances have been classified into concepts. These concepts are then placed in ontology where edges represent semantic relationships among the concepts. Though ontologies are publicly available as a necessary component of the semantic web infrastructure and they serve as the meta-data structure for access to the actual data instances, many of the data instances may be sensitive and should have restricted access among the user communities. Such sensitive information can be illegally inferred from other seemingly unclassified information in combination with the underlying data semantics and inter-relationships revealed by ontologies. In other words, the visibility of ontologies can pose inference threats to the security of data instances. A good amount of research has already been made for controlling access to web ontologies.

The proposed research effort, however, wishes to control access at the query processing level. Considering the ontological structure as a Directed Acyclic Graph (DAG), some work has already been done for controlled access to Digital Libraries. However for library application only object (concept) hierarchy has been considered. In case of generalized semantic web based applications both object and subject (role) hierarchy would be considered and possible conflicts will be mitigated.