Chapter 3 Design Blockchain Components A blockchain platform has multiple components to establish and manage a blockchain network and deploy smart contracts on it. We will look into these components as follows, such as consensus layer, smart contact layer, network communication layer, data store layer, crypto layer, and services such as identify management and API management, as shown in Figure 3-25. • The Consensus layer is responsible for collecting valid transactions in a block and appending a new block in the blockchain network after taking consensus from the node participating in the network. You can use different kinds of consensus algorithms (POW, POS, DPOS, POA, PBFT, BFT) according to the chosen blockchain platform. • The Smart contract layer is responsible for processing transaction requests and determining if transactions are valid or invalid by executing business logic. The smart contract is developed and deployed by the blockchain developer in the blockchain network. • The Communication layer is responsible for peer-to-peer message transport between the nodes that are participating in the network. It supports the interoperation among different blockchain instances. • The Data store layer allows different data stores to be used by other components in modules. • The Crypto layer contains different crypto algorithms to be swapped out without affecting other modules and layers. • The Identify services contains E-certificates and public key infrastructure (PKI), which establishes the trust during setup of blockchain instances. It interacts with member services for enrollment and registration of identities or system entities during network operation. It also provides authentication and authorization to access the events and transactions in the blockchain network. • Data services and API managements enable clients and other DXP applications to interact with the blockchain application and network. 99