Energy-Efficient Agreement Protocols in P2P Overlay Networks

The peer-to-peer (P2P) model is a fully distributed system which is composed of peer processes (peers) which cooperate with each other to achieve a common goal. Here, peers have to efficiently and flexibly make an agreement on one common value which satisfies an agreement condition. We discuss a novel approach to efficiently making an agreement where each peer sends a package of multiple possible values to the other peers at ongoing rounds. By exchanging multiple possible values at once, we can significantly reduce time and number of messages and increase the possibility to reach an agreement. We take advantage of the multipoint relaying (MPR) mechanism to reduce the number of messages to broadcast the messages. Here, if a peer which forwards messages to other peers is faulty, the peers cannot receive messages. In this paper, we newly discuss a broadcast scheme where only the trustworthy peers forward messages. Here, the transmission fault implied by faults of untrustworthy peers can be reduced.