An access control mechanism for P2P collaborations

We introduce a fine grained access control mechanism for Peer-to-Peer collaborations. It is based on the local access control components of the participants. The peers export their access control policies in XACML. Two mechanisms are proposed to combine these policies. The first approach establishes mappings between the export policies. The second approach installs a distributed access control directory. While mappings are created between two peers, a directory contains all rights of all users of all peers. We compare these two approaches and discuss their pros and cons.