What consensus mechanism does Hyperledger Fabric primarily use?

Hyperledger Fabric primarily uses Practical Byzantine Fault Tolerance (PBFT) as its consensus mechanism. PBFT is designed to enable a distributed network to reach consensus despite a certain number of faulty or malicious nodes, specifically in environments where participants are known and permissioned. This mechanism focuses on ensuring that as long as a supermajority of participants (typically two-thirds) is honest, the network can function correctly and reach agreement on transactions.

In Hyperledger Fabric’s architecture, transactions are proposed, endorsed, and then committed in a way that emphasizes efficiency and scalability, which is characteristic of PBFT. This approach is particularly well-suited for enterprise applications where trust is established among the participants, making it efficient for consortium blockchains that use known identities rather than open public blockchains.

In contrast, Proof of Work and Proof of Stake are consensus mechanisms typically associated with public blockchains like Bitcoin and Ethereum, focusing on game-theoretic incentives and requiring significant resource expenditure, which are not suited for the needs of permissioned networks. Delegated Byzantine Fault Tolerance, while it also addresses Byzantine faults, differs in its design and is less commonly implemented in Hyperledger Fabric than PBFT.