Trustworthiness-Based Broadcast Algorithm in Scalable P2P Group

Nowadays information systems are being shifted to distributed architectures, i.e. Grid and P2P models to obtain the benefits like scalability, autonomy, and fault-tolerance. We consider the peer-to-peer (P2P) model as a fully distributed, scalable system, which is composed of peer processes (peers). A group of multiple peers cooperate with each other. Here, peers have to efficiently and flexibly deliver messages to every peer of the group in P2P overlay networks. In order to efficiently and reliably broadcast messages in a scalable group, we take advantage of the multipoint relaying (MPR) mechanism. Here, each peer sends messages to only a subset of its acquaintances. However, if a peer to forward messages to other peers fails to forward the messages, the peers cannot receive the messages. In this paper, we newly discuss a trustworthiness-based broadcast (TBB) algorithm where only trustworthy peers forward messages. Even if untrustworthy peers do not forward messages, messages can be delivered to every peer. Here, the transmission fault implied by faults of untrustworthy peers can be reduced. We evaluate the TBB algorithm in terms of the number of messages transmitted.