An Optimal Agreement Protocol for Hybrid Fault Model

Abstract

The Byzantine agreement (BA) problem is one of the most important problem in designing the fault-tolerant distributed system. In practice, the components in a network (either processors or links) may be subjected to different failure types simultaneously (or called hybrid fault model or mixed faulty types). Most of the earlier work of the BA problem under a hybrid fault model assume that links are fault-free;however, a link can also fail in various faulty types. Examples of link failure include crash, omission, struck-at. or malicious faults. In this paper, we consider the BA problem under a hybrid fault model on communication links. The proposed protocol uses the minimum number of message exchanges and can tolerate the maximum number of allowable faulty links to make each processor reach a common agreement.