BFT is the property of a system that is able to resist the class of failures derived from the Byzantine Generals’ Problem. This means that a BFT system is able to continue operating even if some of the nodes in Blockchain network fail or act maliciously.

It is used as one of the consensus mechanisms in Blockchain networks to protect Blockchains from manipulation by rogue nodes or unknown actors. Practical Byzantine Fault Tolerance was introduced by Miguel Castro and Barbara Liskov at MIT Laboratory and used by Blockchain protocols – Hyperledger, Stellar and Ripple.