Byzantine Fault Tolerance (BFT)

Byzantine Fault Tolerance (BFT) is the ability of a distributed system, such as a blockchain, to continue functioning correctly even when some of its nodes or participants act maliciously or fail to communicate properly. The term originates from the "Byzantine Generals' Problem," a theoretical issue in distributed computing where decentralized parties must agree on a strategy to avoid failure, despite some participants potentially being dishonest. In blockchain systems, BFT is crucial for maintaining network security and ensuring that consensus can be reached even if some nodes behave maliciously. Blockchains like Ethereum 2.0 and Cosmos implement variations of BFT in their consensus mechanisms to ensure that the network remains secure and operational even in the presence of faults or attacks. For example, in a proof-of-stake blockchain, BFT helps ensure that validators reach consensus on the state of the ledger, preventing double-spending and maintaining the network's integrity.