On the complexity of broadcast setup

Abstract

Byzantine broadcast is a distributed primitive that allows a specific party (called "sender") to consistently distribute a value v among n parties in the presence of potential misbehavior of up to t of the parties. Broadcast requires that correct parties always agree on the same value and if the sender is correct, then the agreed value is v. Broadcast without a setup (i.e., from scratch) is achievable from point-to-point channels if and only if t