Distributed Access Enforcement in P2P Networks: When Privacy Comes into Play

In open environments such as peer-to-peer networks, the decision to collaborate with multiple users (e.g., by granting access to a resource) is hard to achieve in practice due to extreme decentralization. The literature contains a plethora of examples where a scalable solution for access control is basic to spur their adoption.Motivated by this need, we introduce a novel protocol to enforce access control in a distributed but also privacy-preserving manner - i.e., so as to minimize the disclosure of privileges and of access policies. Privacy is rather scarce in peer-to-peer systems, for which we believe that our protocol is a valuable contribution. Using extensive simulations on top of real Internet topologies, we illustrate the applicability of our protocol, which is efficient both in terms of communication and rounds of interaction.