Reaching strong consensus in a general network

Abstract

The strong consensus (SC) problem is a variant of the conventional distributed consensus problem (also known as the Byzantine agreement problem). The SC problem requires that the agreed value among fault-free processors be one of the fault-free processor's initial values. Originally, the problem was studied in a fully connected network with malicious faulty processors. In this paper, the SC problem is re-examined in a general network, in which the components (processors and communication links) may be subjected to different faulty types simultaneously (also called the hybrid fault model or mixed faulty types) and the network topology does not have to be fully connected. The proposed protocol can tolerate the maximum number of tolerable faulty components such that each fault-free processor obtains a common value for the SC problem in a general network.