Securing Provenance-Based Audits

Given the significant increase of on-line services that require personal information from users, the risk that such information is misused has become an important concern. In such a context, information accountability is desirable since it allows users (and society in general) to decide, by means of audits, whether information is used appropriately. To ensure information accountability, information flow should be made transparent. It has been argued that data provenance can be used as the mechanism to underpin such a transparency. Under these conditions, an audit's quality depends on the quality of the captured provenance information. Thereby, the integrity of provenance information emerges as a decisive issue in the quality of a provenance-based audit. The aim of this paper is to secure provenance-based audits by the inclusion of cryptographic elements in the communication between the involved entities as well as in the provenance representation. This paper also presents a formalisation and an automatic verification of a set of security properties that increase the level of trust in provenance-based audit results.