On scaling up sensitive data auditing

Abstract

This paper studies the following problem: given (1) a query and (2) a set of sensitive records, find the subset of records "accessed" by the query. The notion of a query accessing a single record is adopted from prior work. There are several scenarios where the number of sensitive records is large (in the millions.) The novel challenge addressed in this work is to develop a general-purpose solution for complex SQL that scales in the number of sensitive records. We propose efficient techniques that improves upon straightforward alternatives by orders of magnitude. Our empirical evaluation over the TPC-H benchmark data illustrates the benefits of our techniques.