Synchronous Consensus in Partial Synchrony

We demonstrate a deterministic Byzantine consensus algorithm with synchronous performance in partial synchrony and naturally leaderless operation. Each message is authenticated only with the digital signature of its creator and resilience to any number of tolerated Byzantine processes requires two communication rounds. The algorithm terminates within a bounded interval of time. It is resilient to transient link faults and asynchrony in a fraction of links with a known distinct size per actual number of faulty processes - links asynchrony and faults are circumvented with up to 3-hop epidemic dissemination. Key finding: resilience to asynchrony of links and the enabled by it leaderless consensus ensure algorithm operation with simultaneous validity, safety, and bounded liveness.