Collaborative Environment, Access Control Model And Technology Research

With the development of Computer Supported Cooperative Work (CSCW) technology, the range and content of collaboration are becoming wider and wider, from traditional office automation, workflow management system (WfMS), interactive groupware, to web-based business process management in virtual organization. However, while people are enjoying the IT civilization, information systems are facing fiercer threats than before. According to the statistic of Computer Security Institute of America, the threat incidents of information system are increasing exponentially and most of them are caused by inter users. So, It is a great challenge and urgent mission to ensure the system security while providing efficient collaboration.Access control is one of the most important security services, which attracts much interests from both academia and industry. In theory, the access control models are used to formally describe the system elements, prove the system security and precisely express the security policy etc. In practice, new technologies are proposed and applied in different areas of business, military and government to directly improve the utility, feasibility and security of information system. In CSCW environment, access control faces more challenges, not only should it prevent outside invasion but also prevent inter unauthorized access due to there are generally thousands of users in large organization to do different task in different period and many partners to collaborate among information systems who may access sensitive information.Based on the analyses of security requirements in collaborative environment, this dissertation addresses a few key problems of access control: security constraint in workflow management system, complex role hierarchy management and interoperation among multi domain etc. The contributions are as following:1. A novel access control model for flexible workflow is presented to solve the problem of security constraint and dynamic adjustment, which considering fine granularity access and active authorization in workflow management system. Using the...