Sublinear-Round Byzantine Agreement under Corrupt MajoritySublinear-Round Byzantine Agreement • February 7th, 2020
Abstract. Although Byzantine Agreement (BA) has been studied for three decades, perhaps somewhat surprisingly, there still exist significant gaps in our understanding regarding its round complexity. A long-standing open question is the following: can we achieve BA with sublinear round complexity under corrupt majority? Due to the beautiful works by Garay et al. (FOCS’07) and Fitzi and Nielsen (DISC’09), we have partial and affirmative answers to this question albeit for the narrow regime f = n/2 + o(n) where f is the number of corrupt nodes and n is the total number of nodes. So far, no positive result is known about the setting f > 0.51n even for static corruption!
