Research On Parallel Update And Publication Methods For XML Data In Distributed Systems

With the rapid developments of internet-based distributed systems, XML is becoming a facto standard of these systems for data representation and exchange over Internet. Because of the scalability properties and the ability of efficiently managing large number of clients and great amount of data, Parallel modification and publishing based third-party for XML data in distributed systems are receiving growing attention, and has become a hot research topic in XML field.Efficiency, confidentiality and integrity are the main properties in parallel modification for XML data in a distributed system. Nowadays, investigation of efficiency and integrity is not as much as that of confidentiality. A strategy is proposed to support parallel modification to XML data in distributed environments. An optimized algorithm, symmetric keys an digital signatures are used to ensure the efficiency, confidentiality and integrity respectively. Different users are able to simultaneously modify different portions or the same portions of the same XML data, and decentralized management of update operations is supported in which a user can perform his privileges and verify the correctness with the digital signature technology and without interaction with the data server. Dynamic users and dynamic policies are supported which means a user may join in or drop out of during the modify process and the privilege of a user over some portions of a XML data may be changed.There is a distinction among the data manager, the data publisher and the client in the third-party architecture. The data manager is the producer and manager of the XML information, the data publishers are responsible for control the XML information and for answering client queries, the clients are the data consumer and update the XML data sometimes. Because it is difficult to verify the data publishers to be trusted, the relevant issue in the third-party architecture is how the data manager can ensure a secure publishing of its XML data. Based on the available publishing methods of XML data and use of digital signature, we propose a XML data publishing architecture with high efficiency and security which clients can easily verify the authentication and completeness of query results.