The chapter discusses the architecture of Hyperledger Fabric, a permissioned blockchain platform developed by the Hyperledger Project. Hyperledger Fabric is designed for enterprise-grade, open-source distributed ledger applications, aiming to advance blockchain technology through a cross-industry open standard. The platform supports smart contracts and is built on a modular architecture that allows for pluggable consensus protocols. Key features of Hyperledger Fabric include: - **Permissioned Blockchain with Immediate Finality:** Ensures that transactions are secure and final once confirmed. - **Non-Validating Peers:** Act as proxies to connect clients to validating peers, though they do not execute transactions. - **Consensus Protocol:** Uses a BFT (Byzantine Fault Tolerance) consensus protocol to execute replicated state machines, handling three types of transactions: deploy, invoke, and query. - **Security Infrastructure:** Supports enrollment, transaction authorization, and confidentiality through public-key certificates and symmetric-key encryption. The chapter also highlights the modular nature of the consensus protocol, which allows for independent development and future enhancements. The current implementation uses PBFT ( Practical Byzantine Fault Tolerance) due to its established research and practical benefits. Hyperledger Fabric is actively developed and maintained by the Hyperledger Project, with ongoing improvements planned for future versions.The chapter discusses the architecture of Hyperledger Fabric, a permissioned blockchain platform developed by the Hyperledger Project. Hyperledger Fabric is designed for enterprise-grade, open-source distributed ledger applications, aiming to advance blockchain technology through a cross-industry open standard. The platform supports smart contracts and is built on a modular architecture that allows for pluggable consensus protocols. Key features of Hyperledger Fabric include: - **Permissioned Blockchain with Immediate Finality:** Ensures that transactions are secure and final once confirmed. - **Non-Validating Peers:** Act as proxies to connect clients to validating peers, though they do not execute transactions. - **Consensus Protocol:** Uses a BFT (Byzantine Fault Tolerance) consensus protocol to execute replicated state machines, handling three types of transactions: deploy, invoke, and query. - **Security Infrastructure:** Supports enrollment, transaction authorization, and confidentiality through public-key certificates and symmetric-key encryption. The chapter also highlights the modular nature of the consensus protocol, which allows for independent development and future enhancements. The current implementation uses PBFT ( Practical Byzantine Fault Tolerance) due to its established research and practical benefits. Hyperledger Fabric is actively developed and maintained by the Hyperledger Project, with ongoing improvements planned for future versions.