Controlled Query Evaluation in Description Logic Ontologies

Controlled Query Evaluation (CQE) preserves confidentiality in query answering over Description Logic ontologies by enforcing data protection policies through a formal notion of censor. This work explores three CQE strategies: computing an optimal censor, reasoning over all optimal censors, and answering queries according to the intersection of all the optimal censors. For such a framework, we present recent data complexity results for lightweight DLs and for the cases in which the query is either a ground atom or a Boolean conjunctive query.