Revisiting Controlled Query Evaluation in Description Logics

Revisiting Controlled Query Evaluation in Description Logics

Domenico Lembo, Riccardo Rosati, Domenico Fabio Savo

Proceedings of the Twenty-Eighth International Joint Conference on Artificial Intelligence
Main track. Pages 1786-1792. https://doi.org/10.24963/ijcai.2019/247

Controlled Query Evaluation (CQE) is a confidentiality-preserving framework in which private information is protected through a policy, and a (optimal) censor guarantees that answers to queries are maximized without violating the policy. CQE has been recently studied in the context of ontologies, where the focus has been mainly on the problem of the existence of an optimal censor. In this paper we instead consider query answering over all possible optimal censors. We study data complexity of this problem for ontologies specified in the Description Logics DL-LiteR and EL_bottom and for variants of the censor language, which is the language used by the censor to enforce the policy. In our investigation we also analyze the relationship between CQE and the problem of Consistent Query Answering (CQA). Some of the complexity results we provide are indeed obtained through mutual reduction between CQE and CQA.
Keywords:
Knowledge Representation and Reasoning: Description Logics and Ontologies
Knowledge Representation and Reasoning: Computational Complexity of Reasoning
Multidisciplinary Topics and Applications: Security and Privacy