Access Control Management in Open Distributed Virtual Repositories and the Grid

The management of access control (AC) policies in open distributed systems (ODS), like the Grid, P2P systems, or Virtual Repositories (databases or data grids) can take two extreme approaches. The first extreme approach is a centralized management of the policy (that still allows a distribution of AC policy enforcement). This approach requires a full trust in a central entity that manages the AC policy. The second extreme approach is fully distributed: every ODS participant manages his own AC policy. This approach can limit the functionality of an ODS, making it difficult to provide synergetic functions that could be designed in a way that would not violate AC policies of autonomous participants. This paper presents a method of AC policy management that allows a partially trusted central entity to maintain global AC policies, and individual participants to maintain own AC policies. The proposed method resolves conflicts of the global and individual AC policies. The proposed management method has been implemented in an access control system for a Virtual Policy that is used in two European 6

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FP projects: eGov-Bus and VIDE. The impact of this access control system on performance has been evaluated and it has been found that the proposed AC method can be used in practice.