A virtual grouping based fault-tolerant scheme for autonomous networks

In an autonomous network environment, each independent node communicates with others by some agreement mechanism to make sure that the majority of nodes can take a common corresponding action. Under a constraint on the amount of faulty nodes, the classical solution, Byzantine Agreement (BA), has been proved to effectively make all healthy nodes able to obey the same command issued from the commander node. The major challenge for BA is its considerable amount of exchanged messages among nodes to reach the consensus, especially when BA is applied to a network environment, which comprises a lot of cooperative nodes. Such a situation may hinder BA from being practically applied in the modern network environment, such as an autonomous wireless sensor network. Thus, we propose a Virtual Grouping Byzantine Agreement (VGBA) scheme to compromise between the percentage of nodes, which can obtain the common command, and the number of exchanged messages produced in the network. That means that VGBA may suffer a lower tolerance capability of faulty nodes and a lower percentage of healthy nodes having the command, but it significantly reduces the message volume. Consequently, the improved VGBA scheme is still applicable while facing a larger number of nodes.