Access Control Policy Combinations for the Grid Using the Policy Machine

Many researchers have tackled the architecture and requirements aspects of grid security, concentrating on the authentication or authorization mediation instead of authorization techniques, especially the topic of policy combination. Policy combination is an essential requirement of grid, not only because of the required remote (or global) vs. local interaction between grid members, but also the dynamic scalability nature of handling the joining and leaving of grid membership. However, evolving from the general security requirements of grid, the independency of a grid member's access control system is critical and needs to be maintained when the access decision is determined by the combination of global and local access control policies. The Policy Machine (PM) provides features which not only can meet the significant independency requirement but also have better performance, easier management, and more straightforward policy expression than most of the popular policy combination techniques for grid.