Brief announcement: capacity of byzantine agreement with finite link capacity - complete characterization of four-node networks

In this paper, we consider the problem of maximizing the throughput of Byzantine agreement, when communication links have finite capacity. Byzantine agreement is a classical problem in distributed computing, with initial solutions presented in the seminal work of Pease, Shostak and Lamport. The notion of throughput here is similar to that used in the networking/communications literature on unicast or multicast traffic. We identify necessary conditions for an agreement throughput of R to be achievable. We also provide tight sufficient conditions by construction for agreement throughput R in four-node networks.