Effects of Cooperation--Based Peer-to-Peer Authentication on System Performance

Fully distributed file sharing systems, where participants share content and collaborate in a peer-to-peer (P2P) manner, have to deal with a highly dynamic environment to ensure that even when some nodes are unavailable, others can still perform the task through the coalition of cooperating parties. Therefore, cooperation-based services have been extensively deployed over the majority of P2P networks. This leads, however, to significant challenges for network services and data management, especially facilitating security properties. In a previous work, we presented a protocol for content authentication based on attribute certificates that does not rely on the existence of a public key infrastructure. Instead, peers cooperate to guarantee data integrity. In this context, it is reasonable to assume that peers would cooperate aimed at maximizing the expected benefit, but, generally, efficiency performance pays dearly for this. In this paper, we present an experimental evaluation of our analytical model in order to validate its dependability, and also discussing its tolerance under failures.