Consider a completely asynchronous network consisting of n parties where every two parties are connected by a private channel. An adversary At with unbounded computing power actively controls at most t = (n 3 - 1) out of n parties in Byzantine fashion. In this setting, we say that is a t-resilient, (1 - )-terminating Asynchronous Byzantine Agreement (ABA) protocol, if satisfies all the properties of Byzantine Agreement (BA) in asynchronous settings tolerating At and terminates (i.e every honest party terminates ) with probability at least (1- ). In this work, we present a new t-resilient, (1 - )-terminating ABA protocol which privately communicates O(Cn6 ) bits and A-casts1 O(Cn6 ) bits, where = 2-() and C is the expected running time of the protocol. Moreover, conditioned on the event that our ABA protocol terminates, it does so in constant expected time; i.e., C = O(1). Our ABA protocol is to be compared with the only known t-resilient, (1 - )-terminating ABA protocol of [5] in th...
Arpita Patra, Ashish Choudhary, C. Pandu Rangan