Tutorial on the Internals of Permissioned Blockchains and on How to Build Applications with Hyperledger Fabric

Blockchain is an emerging technology, considered increasingly often beyond the cryptocurrency world for business-to-business use-cases. In contrast to public blockchains such as Bitcoin, that are open systems in which anyone can participate, in business-to-business scenarios the membership of the service is controlled (permissioned blockchain). This permits the use of Byzantine fault tolerant (BFT) consensus protocols at the core of the service to establish a total order of transactions, instead of the more expensive Proof-of-Work-based consensus protocols. Permissioned blockchains typically set out to solve problems in the space where databases have traditionally resided, with the main difference being that the former decentralizes trust. There are numerous research proposals in the intersection of databases and blockchains. Sadly, there are still many misconceptions about this technology which leads to confusion in the community. The main goal of this primer is to give an overview of the relevant topics and provide pointers for further reading