A Bayesian model for disclosure control in statistical databases

摘要

The paper proposes a novel approach for on-line max and min query auditing, in which a Bayesian network addresses disclosures based on probabilistic inferences that can be drawn from released data. In the literature, on-line max and min auditing has been addressed with some restrictive assumptions, primarily that sensitive values must be all distinct and the sensitive field has a uniform distribution. We remove these limitations and propose a model able to: provide a graphical representation of user knowledge; deal with the implicit delivery of information that derives from denying the answer to a query; and capture user background knowledge. Finally, we discuss the results of experiments aimed at assessing the scalability of the approach, in terms of response time and size of the conditional probability table, and the usefulness of the auditor system, in terms of probability to deny.