Small Byzantine Quorum Systems

In this paper we present two protocols for asynchronous Byzantine Quorum Systems (BQS) built on top of reliable channels—one for self-verifying data and the other for any data. Our protocols tolerate ¢ Byzantine failures with ¢ fewer servers than existing solutions by eliminating nonessential work in the write protocol and by using read and write quorums of different sizes. Since engineering a reliable network layer on an unreliable network is difficult, two other possibilities must be explored. The first is to strengthen the model by allowing synchronous networks that use time-outs to identify failed links or machines. We consider running synchronous and asynchronous Byzantine Quorum protocols over synchronous networks and conclude that, surprisingly, ”self-timing” asynchronous Byzantine protocols may offer significant advantages for many synchronous networks when network time-outs are long. We show how to extend an existing Byzantine Quorum protocol to eliminate its depen...

• Type: Conference
• Year: 2002
• Where: DSN
• Authors: Jean-Philippe Martin, Lorenzo Alvisi, Michael Dahlin
• Keywords: Asynchronous Byzantine Quorum, Byzantine Quorum Protocol, Computer Networks, DSN 2002, Synchronous Networks