Access control model and labelling scheme for efficient querying and updating XML data

In this thesis, we make two major contributions that help the tasks of querying, updating, and managing XML data become quick and safe. First, we propose a new labelling scheme for dynamic XML data that supports the representation of the ancestor – descendant relationship and sibling relationship between nodes. Our unique way of labelling codes can also help users easily determine the depth (level) of the XML tree. Moreover, it also supports the process of updating XML data without the need of re-labelling existing labels, hence facilitating fast update. Some experimental works have been conducted to show its effectiveness. Secondly, for XML security purposes, we propose a fine-grained access control model, named SecureX, which supports read and write privileges. With our novel access control concept, various access types are introduced, including those for determining if a user has the right to change XML structure. SecureX ensures that, crucial information will be accessible only to authorized entities. Furthermore, SecureX can be integrated well with a dynamic labelling scheme to eliminate repetitive labelling and pruning processes when determining a user view. This brings about advantages of speeding up searching and querying processes