XML access control with policy matching tree

Abstract

XML documents are frequently used in applications such as business transactions and medical records involving sensitive information. Access control on the basis of data location or value in an XML document is therefore essential. However, current approaches to efficient access control over XML documents have suffered from scalability problems because they tend to work on individual documents. To resolve this problem, we proposed a table-based approach in [28]. However, [28] also imposed limitations on the expressiveness, and real-time access control updates were not supported. In this paper, we propose a novel approach to XML access control through a policy matching tree (PMT) which performs accessibility checks with an efficient matching algorithm, and is shared by all documents of the same document type. The expressiveness can be expanded and real-time updates are supported because of the PTM's flexible structure. Using synthetic and real data, we evaluate the performance and scalability to show it is efficient for checking accessibility for XML databases. © Springer-Verlag Berlin Heidelberg 2005.