A Distributed Authorization System with Mobile Usage Control Policies

Distributed systems, such as the Cloud, are widely used for solving large problems, because they provide big computational power at a low cost. From the security point of view, distributed systems pose new challenges, because the applications running on the components of the system could cooperate to access the system's resources. Hence, the security support should consider all the accesses performed by the applications run by the same user on distinct nodes of a distributed system as the behaviour of that user. To address this problem, this paper proposes mobile usage control policies that, besides regulating the usage of the system resources, also define the exchange of some policy fragments among the nodes of the distributed system. In this way, the usage of resources performed on one node of the distributed system affects the right of accessing resources on other nodes of the system. A reference scenario where mobile usage control policies could be successfully adopted is the Cloud environment.