A Survey of Query Auditing Techniques for Data Privacy

17.1 Introduction This chapter is a survey of query auditing techniques for detecting and preventing disclosures in a database containing private data. Informally, auditing is the process of examining past actions to check whether they were in conformance with official policies. In the context of database systems with specific data disclosure policies, auditing is the process of examining queries that were answered in the past to determine whether answers to these queries could have been used by an individual to ascertain confidential information forbidden by the disclosure policies. Techniques used for detecting disclosures could potentially also be used or extended to prevent disclosures, and so in addition to the retroactive auditing mentioned above, researchers have also studied an online