Reach Unanimity Problem on an Unknown Network

Abstract

The Byzantine Agreement is an important topic in the reliable distributed system because the system can cope with the influences from faulty components only when the agreement is achieved. In the literature concerned, the BA problem has been well formulated in a Fully Connected Network (FCN), a Generalized Connected Network (GCN), and a MultiCasting Network (MCN) under the assumption that each processor in the network has the common knowledge of the graphic information about the entire network structure. However, in the real world, each processor may not have the common knowledge of the graphic information about the entire network structure. That is, the processors may only have the partial knowledge as to their own graphic information. In this paper, the Byzantine Agreement problem will be visited in an Unknown Network (UNet) to increase the capability of fault tolerance by allowing faulty processors with dual failure mode. The proposed protocols, the Unknown Agreement Protocol (UAP) and the Relay Fault-tolerance Channel (RFC), use the minimum number of rounds of message exchange and can tolerate the maximum number of faulty processors allowed.