Overview
Byzantine Fault Tolerance (BFT) is a critical requirement for any decentralized network. It refers to the ability of a distributed computer system to reach a single, correct agreement despite the presence of 'Byzantine faults'—nodes that provide conflicting information or stop responding entirely.
The Byzantine Generals Problem
This is a thought experiment where several generals must agree on a time to attack a city. Some generals may be traitors and try to prevent consensus by sending different messages to different generals. A BFT system is one that can overcome this treachery.
Threshold
Mathematically, most BFT systems can tolerate up to one-third (33%) of the nodes being faulty or malicious while still reaching a correct consensus.