Consensus Protocol

A consensus protocol allows a set of validators to create the logical appearance of a single database. The consensus protocol replicates submitted transactions among the validators, executes potential transactions against the current database, and then agrees on a binding commitment to the ordering of transactions and resulting execution. As a result, all validators can maintain an identical database for a given version number following the state machine replication paradigm.

The XMETA protocol uses a variant of the HotStuff consensus protocol, a recent Byzantine fault-tolerant (BFT) consensus protocol, called XMETABFT. It provides safety (all honest validators agree on commits and execution) and liveness (commits are continually produced) in the partial synchrony model defined in the paper "Consensus in the Presence of Partial Synchrony" by Dwork, Lynch, as well as newer protocols such as Tendermint.