Byzantine Fault Tolerance
Byzantine Fault Tolerance — The ability of a distributed protocol to reach correct outcomes even when some participants behave arbitrarily, inconsistently, or maliciously.
Distributed-Systems Context
Byzantine faults are stronger than crash faults because a faulty node can send conflicting information to different peers. BFT protocols therefore require different quorum assumptions, message complexity, identity/trust models, and often higher latency than crash-fault consensus.