We study communication complexity of consensus in synchronous message-passing systems with processes prone to crashes. The goal in the consensus problem is to have all the nonfaulty processes agree on a common value from among the input ones, after each process has been initialized with a binary input value. The system consists of n processes and it is assumed that at most t < n processes crash in an execution. A consensus algorithm that tolerates up to t failures is called fast when its time complexity is O(t). All the previously known fast deterministic consensus solutions sent Ω(n2 ) bits in messages. We give a fast deterministic consensus algorithm that has processes send only O(n log4 n) bits. In our solution, processes exchange messages according to topologies of overlay graphs that have suitable robustness and connectivity properties related to graph expansion. Categories and Subject Descriptors C.2.4 [Computer-Communication Networks]: Distributed Systems; D.4.5 [Operating...
Bogdan S. Chlebus, Dariusz R. Kowalski, Michal Str