A Flexible Attribute Based Access Control Method for Grid Computing

Grid systems have huge and changeable user groups, and different autonomous domains always have different security policies. The attribute based access control (ABAC) model, which is flexible and scalable, is more suitable for Grid systems. This paper describes a method of building a flexible access control mechanism that is based on ABAC and supports multiple policies for Grid computing. Firstly an attribute based multipolicy access control model ABMAC is submitted. Compared with ABAC, ABMAC can describe multiple heterogeneous policies, and each policy is encapsulated without changing its descriptions. Then by extending the authorization architecture of XACML, the paper puts forward an authorization framework that supports ABMAC and is implemented in the Globus Toolkit release 4 (GT4) (Few parts of the authorization framework described in this paper can only be found in Globus Toolkit CVS repository. A more completed authorization framework will be appeared in the Globus Toolkit release 4.2). Basing on the concept of policy encapsulation, the framework provides a flexible and scalable authorization mechanism that can support multiple existing policies in a Grid system. The design and implementation details of GT4 authorization framework are also well discussed.