Byzantine fault tolerance
termcloudsecurity
Stands for: BFT
Agreement that survives members which do not merely fail, but lie - sending different answers to different peers, whether through corruption or malice.
Ordinary consensus assumes a failed node goes quiet. Byzantine tolerance drops that assumption, which is much harder and much more expensive: the classic result is that agreement needs more than two thirds of members to be honest. Most enterprise systems do not pay for it, and are right not to, because they control every node. It becomes necessary exactly when they do not - blockchains, and any system whose participants are mutually distrustful - which is the real technical distinction between a distributed database and a ledger.
Also known as: BFT, byzantine generals