Relevancy based access control of versioned XML documents

Integration of version and access control of XML documents has the benefit of regulating access to rapidly growing archives of XML documents. Versioned XML documents provide us with valuable informations on dependencies between document nodes, but at the same time presenting the risk of undesirable data disclosure. In this paper we introduce the notion of relevancy-based access control, which realizes protection of versioned XML documents by various types of relevancy, such as version dependencies, schema similarities and temporal proximity. We define a new path query language XVerPath over XML document versions, which can be utilized for specifying relevancy-based access control policies. We also introduce the notion of relevancy class, for collectively and compactly specifying relevancy-based policies.