Constant-Space Localized Byzantine Consensus

Adding Byzantine tolerance to large scale distributed systems is considered non-practical. The time, message and space requirements are very high. Recently, researches have investigated the broadcast problem in the presence of a f̀ -local Byzantine adversary. The local adversary cannot control more than f̀ neighbors of any given node. This paper proves sufficient conditions as to when the synchronous Byzantine consensus problem can be solved in the presence of a f̀ -local adversary. Moreover, we show that for a family of graphs, the Byzantine consensus problem can be solved using a relatively small number of messages, and with time complexity proportional to the diameter of the network. Specifically, for a family of bounded-degree graphs with logarithmic diameter, O(log n) time and O(n log n) messages. Furthermore, our proposed solution requires constant memory space at each node. This is the author’s copy of the paper. Please see http://www.springer.de/comps/lncs/index.html c ©Springer-Verlag