Feldman P, Micali S: Byzantine correspondence in a time constantly awaited (and trusting no one). Proceedings of the 26th Annual IEEE Symposium on Foundations of Computer Science pp 267-276, 1985 In World 1, the adversary damages a series $V$ $f/2$nodes that do not contain the specified sender. Suppose $U$ is the remaining nodes. All parties in $V$ behave like honest nodes, except (i) they ignore the first $f/2$ messages sent to them and (ii) they do not send messages to each other. Suppose the honest designated sender has input 0. For validity to be valid, all honest nodes must spend 0. In 1980, the PSL showed the first result of achieving a consensus in the presence of Byzantine opponents. However, their solution had exponential communication complexity (in $n$, the number of parties).
Message Complexity Of Byzantine Agreement