# Controlled Query Evaluation through Epistemic Dependencies

arXiv: https://arxiv.org/abs/2405.02458 · HTML: https://mlsanity.com/paper/2405.02458/

## Key facts

- No citing papers in the map yet (data through 14 Oct 2026).
- Builds on 2 of its 22 references that are in the map.
- First posted on arXiv 3 May 2024.

## Builds on (most cited first, 2 of 2)

- [Sound, Complete and Minimal UCQ-Rewriting for Existential Rules](https://mlsanity.com/paper/1311.3198/) (2013)
- [Controlled Query Evaluation for Datalog and OWL 2 Profile Ontologies](https://mlsanity.com/paper/1504.06529/) (2015)

## Abstract (arXiv)

In this paper, we propose the use of epistemic dependencies to express data protection policies in Controlled Query Evaluation (CQE), which is a form of confidentiality-preserving query answering over ontologies and databases. The resulting policy language goes significantly beyond those proposed in the literature on CQE so far, allowing for very rich and practically interesting forms of data protection rules. We show the expressive abilities of our framework and study the data complexity of CQE for (unions of) conjunctive queries when ontologies are specified in the Description Logic DL-Lite_R. Interestingly, while we show that the problem is in general intractable, we prove tractability for the case of acyclic epistemic dependencies by providing a suitable query rewriting algorithm. The latter result paves the way towards the implementation and practical application of this new approach to CQE.