Keeping Secrets in Modalized DL Knowledge Bases

Gopalakrishnan Krishnasamy Sivaprakasam, Giora Slutzki

2017

Abstract

In this paper we study Secrecy-Preserving Query Answering problem under the Open World Assumption (OWA) for ELH Knowledge Bases. Here ELH is a top-free description logic ELH augmented with a modal operator ^. We employ a tableau procedure designed to compute a rooted labeled tree T which contains information about some assertional consequences of the given knowledge base. Given a secrecy set S, which is a finite set of assertions, we compute a function E, called an envelope of S, which assigns a set of assertions to each node of T. E provides logical protection to the secrecy set S against the reasoning of a querying agent. Once the tree T and an envelope E are computed, we define the secrecy-preserving tree TE. Based on the information available in TE, assertional queries with modal operator ^ can be answered efficiently while preserving secrecy. To the best of our knowledge, this work is first one studying secrecy-preserving reasoning in description logic augmented with modal operator ^. When the querying agent asks a query q, the reasoner answers “Yes” if information about q is available in TE; otherwise, the reasoner answers “Unknown”. Being able to answer “Unknown” plays a key role in protecting secrecy under OWA. Since we are not computing all the consequences of the knowledge base, answers to the queries based on just secrecy-preserving tree TE could be erroneous. To fix this problem, we further augment our algorithms by providing recursive query decomposition algorithm to make the query answering procedure foolproof.

Paper Citation

in Harvard Style

Krishnasamy Sivaprakasam G. and Slutzki G. (2017). Keeping Secrets in Modalized DL Knowledge Bases . In Proceedings of the 9th International Conference on Agents and Artificial Intelligence - Volume 2: ICAART, ISBN 978-989-758-220-2, pages 591-598. DOI: 10.5220/0006202505910598

in Bibtex Style

@conference{icaart17,
author={Gopalakrishnan Krishnasamy Sivaprakasam and Giora Slutzki},
title={Keeping Secrets in Modalized DL Knowledge Bases},
booktitle={Proceedings of the 9th International Conference on Agents and Artificial Intelligence - Volume 2: ICAART,},
year={2017},
pages={591-598},
publisher={SciTePress},
organization={INSTICC},
doi={10.5220/0006202505910598},
isbn={978-989-758-220-2},
}

in EndNote Style

TY - CONF
JO - Proceedings of the 9th International Conference on Agents and Artificial Intelligence - Volume 2: ICAART,
TI - Keeping Secrets in Modalized DL Knowledge Bases
SN - 978-989-758-220-2
AU - Krishnasamy Sivaprakasam G.
AU - Slutzki G.
PY - 2017
SP - 591
EP - 598
DO - 10.5220/0006202505910598