2[3]ITUT-X.509:Information technology-Open Systems Interconnection-The Directory:Public-key and attribute certificate frameworks[S].P15-20.
3[1]WFMC-TC-0021019.Workflow Management Coalition Work-flow Security Considerations White Paper.http://www.wfmc.org.
4[2]John A.Miller,Mei Fan,Amit,P.Sheth and Kry J.Kochut.ACM Trans.on Information and System Security.Security in Web-based Workflow Management Systems.2002.
5[3]Kandala S,Sandhu R.Secure Role-based Workflow Models[J].In Proceedings of the 15th IFIP WGl1.3 Working Conference on Database Security,Kluwer,2002:45-58.
6[5]R K Thomas,R Sandhu.Task-based authorization controls (TBAC),A family of models for active and enterprise-oriented au-thorization managenent.In:T Y Lin.S Qian eds.Database Security XI:Status and Prospects.CA:Chapman & Hall,1997,166-181.
