In this chapter, we have seen the differences between permissionless (public) and permissioned (private) blockchains and the main implications of different consensus mechanisms and transaction management. We also addressed the various architectural, application-related, and security-related aspects of Hyperledger Fabric, one of the most popular enterprise-class permissioned blockchains, highlighting the advantages of adopting a modular architecture with Hyperledger Fabric. Special attention was paid to trusted execution environments and preserving transaction privacy by exploiting multi-channel functionality and private data.
In the next chapter, our journey continues with an analysis of the security of decentralized apps and smart contracts in the Ethereum environment.