Sky: an Opinion Dynamics Framework and Model for Consensus over P2P Network

The decentralized nature of P2P network increases robustness because it removes single points of failure, however, traditional Byzantine consensus does not work in P2P network due to Sybil attack while existing Sybil-proof consensus based on compute power can't resist adversary with dominant compute power. We proposed the sky framework to apply opinion dynamics in P2P network for consensus, as well as the sky model to maximize performance. The sky framework is Sybil-proof through trust relationships and with it consensus may emerge from local interactions of each node with its direct contacts without topology, global information or even sample of the network involved. The sky model has better performance of convergence than existing models in literatures, and its lower bound of fault tolerance performance is also analyzed and proved. Comparing to compute power based consensus, our approach enables disarming faulty or potentially malicious nodes by unfollowing them. To the best of our knowledge, it's the first work to bring opinion dynamics to P2P network for consensus.