EquiCast: Scalable multicast with selfish users

Peer-to-peer (P2P) networks suffer from the problem of "freeloaders", i.e., users who consume resources without contributing anything in return. In this paper, we tackle this problem taking a game theoretic perspective by modeling the system as a non-cooperative game. We introduce EquiCast, a wide-area P2P multicast protocol for large groups of selfish nodes. EquiCast is the first P2P multicast protocol that is formally proven to enforce cooperation in selfish environments. Additionally, we prove that EquiCast incurs a low constant load on each user. © 2009 Elsevier B.V. All rights reserved.