Consortiums (an association, typically of several participants such as banks, e-commerce sites, government entities, hospitals, and so on) can use blockchain technology to solve many problems and make things faster and cheaper. Although they figure out how blockchain can help them, an Ethereum implementation of blockchain doesn't specifically fit them for all cases. Although there are other implementations of blockchain (for example, Hyperledger) that are built specially for consortium, as we learned Ethereum throughout the book, we will see how we can hack Ethereum to build a consortium blockchain. Basically, we will be using parity to build a consortium blockchain. Although there are other alternatives to parity, such as J.P. Morgan's quorum, we will use parity as at the time of writing this book, it has been in existence for some time, and many enterprises are already using it, whereas other alternatives are yet to be used by any enterprise. But for your requirements, parity may not be the best solution; therefore, investigate all the others too before deciding which one to use.

In this chapter, we'll cover the following topics:

• Why is Ethereum unfit for consortium blockchain?
• What is a parity node and what are its features?
• What is the Proof-of-Authority consensus protocol and what types of PoA are supported by parity?
• How does the Aura consensus protocol work?
• Downloading and installing parity
• Building a consortium blockchain using parity