1. Elisa Bertino Dept. of Computer Science University of Milano Page 1 Author-X Secure and selective access and flexible distribution mechanisms for XML documents Elisa Bertino

2. Dept. of Computer Science University of Milano Page 2 Features of Author-X Varying protection granularity levels Propagation of authorization across document nested structures Protection of documents not conforming to DTD Content-based access control Support for large and dynamic user population (based on credentials) Protection under different document distribution modes (pull, push)

3. Elisa Bertino Dept. of Computer Science University of Milano Page 3 Open issues Support for trust negotiation Extension to access control for services and general resources Access policies taking into account contextual information concerning users, such as the user location or the time of the day Integration with platforms for privacy preferences