Preface

Blockchain is a disruptive technology that promises to disrupt many sectors of the global economy. This innovative technology aims to revolutionize those industries that rely on intermediation and trust by shifting the paradigm away from the currently dominant centralized architectures and toward decentralization.

The past couple of years have seen the exponential growth of blockchain, which has evolved into multiple forms and currently comprises many different technologies and tools, some mature, others relatively new, all of which makes understanding and mastering the key ideas and concepts a difficult task.

This is where this book enters the picture. There are many books out there aiming to capitalize on blockchain's current popularity, but, in our opinion, a vast majority of them concentrate on blockchain's theoretical or speculative aspects: in other words, what blockchain could be used for in future, without providing any concrete details on how these things can be achieved in practice. This book is different: it's more pragmatic. From the outset, this book details what can be done with blockchain technology now, and how to do it, by guiding the reader through a series of in-depth, hands-on implementations.

The book is organized into several main parts. It starts by providing an introduction and high-level overview of blockchain's concepts, before moving on to present different use cases and practical implementations based on the Ethereum, Bitcoin, and Hyperledger blockchains.

Who this book is for

This book is aimed at the blockchain novice, and aims to provide an easy way to learn how to conduct a blockchain-based project. It provides comprehensive coverage of the technical details associated with different blockchain solutions, and step-by-step guidance on implementing typical blockchain projects. By the end of the book, the reader will be able to build and maintain reliable and scalable distributed systems based on blockchain.

What this book covers

Chapter 1, Say Hello to Blockchain, serves as a general introduction, and explains the general concepts on which blockchain technology is based.

Chapter 2, Building a Bitcoin Payment System, introduces the specifics of Bitcoin by first building a customer-friendly payment system, before moving on to looking in more detail at the use of smart contracts on the Bitcoin blockchain.

Chapter 3, Building Your Own Cryptocurrency, builds on the general understanding of Bitcoin learned in the previous chapter to then create a new currency based on the Bitcoin code base.

Chapter 4, Peer-to-Peer Auction in Ethereum, introduces the basic features, concepts, and tools of Ethereum that are required to build a decentralized application. This chapter introduces the Solidity smart contract language that is used extensively in later chapters.

Chapter 5, Tontine Game with Truffle and Drizzle, builds on the previous Ethereum chapter to create a more complex decentralized application, leveraging more advanced features of Solidity, together with the Truffle development environment.

Chapter 6, Blockchain-Based Futures System, continues to build on the previous two Ethereum chapters, this time focusing on how smart contracts can interact with the outside world using oracles and third-party APIs.

Chapter 7, Blockchains in Business, introduces the idea of private enterprise blockchains and their use cases, before detailing how to implement a private network using an enterprise-focused fork of Ethereum called Quorum.

Chapter 8, Creating an ICO, continues the theme of using the Ethereum blockchain for business by describing, in detail, how to create and run an initial coin offering, also known as a token sale.

Chapter 9, Distributed Storage – IPFS and Swarm, builds on the previous Ethereum chapters to explore how to incorporate decentralized file storage in a decentralized application.

Chapter 10, Supply Chain on Hyperledger, introduces the third blockchain network of the book: Hyperledger. This chapter introduces the main concepts and basic features of Hyperledger, and how it differs from Bitcoin and Ethereum, before describing a practical implementation of how Hyperledger can be used to run a supply chain.

Chapter 11, Letter of Credit (LC) Hyperledger, builds on the basics from the previous chapter to implement a letter of credit issued between two banks and two transacting customers.

To get the most out of this book

The book assumes that you are comfortable using a command-line interface, though doesn't require any formal shell scripting skills. Basic language-agnostic programming knowledge is also assumed, and, in some cases, a familiarity with a particular language would be beneficial, though isn't a requirement.

As the book covers many languages and technologies, it is unlikely the reader will be familiar with all of them. As such, a willingness to learn is certainly recommended.

Download the example code files

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The code bundle for the book is also hosted on GitHub at https://github.com/PacktPublishing/Blockchain-By-Example. In case there's an update to the code, it will be updated on the existing GitHub repository.

We also have other code bundles from our rich catalog of books and videos available at https://github.com/PacktPublishing/. Check them out!

Download the color images

We also provide a PDF file that has color images of the screenshots/diagrams used in this book. You can download it here: https://www.packtpub.com/sites/default/files/downloads/9781788475686_ColorImages.pdf.

Conventions used

There are a number of text conventions used throughout this book.

CodeInText: Indicates code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles. Here is an example: "You can, at any level, use console.log() to print the received values in the console."

A block of code is set as follows:

var bitcoin = require('bitcoinjs-lib');
var rp = require('request-promise');

Any command-line input or output is written as follows:

sudo add-apt-repository ppa:bitcoin/bitcoin 
sudo apt-get update

Bold: Indicates a new term, an important word, or words that you see on screen. For example, words in menus or dialog boxes appear in the text like this. Here is an example: "The customer can check the transaction details before proceeding with the payment by pressing the Transaction details button."

Warnings or important notes appear like this.

Tips and tricks appear like this.

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