An Approach to Construct Secure View for XML

XML has been in prevalent use nowadays, so it is necessary to take measures to ensure the security of XML data. Recently, many access control models have been presented and many models are based on the concept of security views, which provide for each user group (a) an XML view consisting of all and only the information that the users are authorized to access, and (b) a view DTD that the XML view conforms to. Security views effectively protect sensitive data from access and potential inferences by unauthorized users, and provide authorized users with necessary schema information to facilitate effective query formulation and optimization. In this paper we study secure access control policies and provide new methods to build secure views for XML DTD with recursion. The main idea is to transform recursive DTD to the equipollent DTD without recursion. And we present a more efficient algorithm to derive such security views.