Byzantine fault tolerance (BFT) is a distributed system feature that allows the system to operate continuously even if one or more system components fail or have unexpected consequences. BFT is also an example of a fault tolerance system that can control unexpected faults, such as faults that cause system components to become non-functional or convey information that is not as expected.

It features a solution to the Byzantine Generals problem, which is a game theoretic problem that describes the shortcomings in communication between Byzantine generations that require high power to reach consensus. The problem states that Byzantine generations have the power to destroy the consensus made by other generations, resulting in a dysfunctional system.

BFT can be obtained through consensus algorithms that use Byzantine fault control protocols, such as Practical Byzantine Fault Tolerance (pBFT). pBFT is a consensus algorithm that uses quorum to control Byzantine faults. This algorithm can be implemented in distributed systems, such as blockchains.