A privilege is a security attribute which may be shared by possibly many principals. We focus on the kinds of privileges defined in the XGSS and CORBA specifications, that include groups, roles, clearances and capabilities [7]. For example, Bill Clinton might have the privileges:
role: President-of-USA
capability: OccupyWhiteHouse
group: AmericanPresidents
accessId: WilliamClinton
Note that the permission to occupy the White House may be a capability transiently issued to him, with an expiration at the end of his presidency.