An Abstract Model of the Virtual Organization Membership Service

Grid systems involve the coordination of resources and services that are not subject to centralized control, span multiple trust domains and are accessible by a large number of users. They require a functionality for mapping users and credentials that exist at the virtual level to users and credentials that exist at the physical level. In this paper, we present a rigorous modeling of the Virtual Organization Membership Service (VOMS), a credential-based access control system. It enables the management and secure distribution of roles, groups and capabilities of users at the virtual level by improving both scalability and flexibility aspects.