具有时限性和区域性特征的基于角色转授权模型

对分布式系统基于角色转授权模型（Role based Delegation Model，RDM）进行深入研究。RDM更适合于分布式系统的授权管理，但当前的几种RDM都不支持时限性和区域性。根据分布式系统的特点，首先提出了转授权的区域性特征；基于转授权的时限性特征和区域性特征对RDM2000模型进行扩充，提出了完备的具有时限性和区域性特征的基于角色的转授权模型（Temporary and Domain Role based Delegation Model，TDRDM）；并给出了基于TDRDM的转授权（delegation）和转授权撤销（delegation revocation）机制；最后通过分布式系统实例对TDRDM模型的转授权进行描述。

Temporary and domain role-based delegation model

Access control delegation model of distributed systems was researched in this paper.Role-based delegation model(RDM)is more suitable for distributed system environments,but current RDMs don't support temporal and domanial delegation.The domain feature of delegation was proposed firstly,which based on the character of distributed systems.A temporary and domain role-based delegation model(TDRDM)was presented,which was an extension of RDM2000 by supporting temporary and domain role-based delegation.The new mechanisms of delegation and delegation revocation were explored,which based on TDRDM.Finally,a model test was presented by an example of distributed system.As results,TDRDM not only ensures the time constraints,but also ensures the domain constraints of delegation in distributed system environments.