Joachim Biskup, Piero A. Bonatti:
Controlled Query Evaluation with Open Queries for a Decidable
Relational Submodel.
Abstract
Controlled query evaluation for logic-oriented information
systems provides a model for the dynamic enforcement of confidentiality
policies even if users are able to reason about a priori knowledge and the
answers to previous queries. Previous foundational work simply assumes
that the control mechanism can solve the arising entailment problems (no
matter how complex they may be), and deals only with closed queries. In
this paper, we overcome these limitations by refining the abstract model
for appropriately represented relational databases. We identify a
relational submodel where all instances share a fixed infinite Herbrand
domain but have finite base relations, and we require finite and
domain-independent query results. Then, via suitable syntactic
restrictions on the policy and query languages, each entailment problem
occurring in the framework can be equivalently expressed as a universal
validity problem within the Bernays-Schönfinkel class, whose (known)
decidability in the classical setting is extended to our framework. For
both refusal and lying, we design and verify evaluation methods for open
queries, exploiting controlled query evaluation of appropriate sequences
of closed queries, which include answer completeness tests.
URL:
http://rewerse.net/publications/rewerse-publications.html#REWERSE-RP-2006-018
@inproceedings{REWERSE-RP-2006-018, author = {Joachim Biskup and Piero A. Bonatti}, title = {Controlled Query Evaluation with Open Queries for a Decidable Relational Submodel}, booktitle = {Proceedings of 4th International Symposium on Foundations of Information and Knowledge Systems, Budapest, Hungary (14th--17th February 2006)}, year = {2006}, volume = {3861}, series = {LNCS}, pages = {43--62}, url = {http://rewerse.net/publications/rewerse-publications.html#REWERSE-RP-2006-018} }