Research Of The Delegation Based On D-TRBAC In Workflow Context

Workflow Technology is a new subject in Computer Support Cooperative Work (CSCW)field. During the use of workflow technology, we often come across the delegate problemconsidering the security of workflow. Delegation problem can be described as followed, someusers may want to delegate a part or the whole of a task to others as they like without theadministrator's help.This paper makes detail analysis and summary on the delegation and access control ofthe workflow technology and finds that most delegation problems are studied based on theaccess control strategies. In the last few years, the access control strategies were being studiedcontinuously and several new access models were developed to adapt to the development ofworkflow technology. Being limited by the old access control strategies, most delegationmodel developed can' t resolve the delegation problem adequately, such as the fine graindelegation problem, multi-delegate, the revocation of delegation. So many people are turningto the study of delegation problem under new access control strategies.According to the problems above, this paper put forward a simple access control modelfor T-RBAC(Task-Role Based Access Control). Based on this model, this paper developed anew D-TRBAC(Delegate in Task-Role Based Access Control) in combination with thedelegate problem. After given the new definition of the items and constrains of this model,this paper put forward a solution for special delegate, multi-delegate, revocation and someother problems based on this model and also proved the correctness of this model. At last, weexpanded these problems to the transfer to task, strong delegation, down-grade revocation andso'on.Based upon theoretical research achievement, a workflow based, universal and adaptivedocument transaction subsystem was developed in the background of ESwing OA system'sdesign and implementation. It also realized the multi-delegate and the revocation ofdelegation problem.