Boro Sitnikovski - Introducing Blockchain with Lisp: Implement and Extend Blockchains with the Racket Language

Any source code or other supplementary material referenced by the author in this book is available to readers on GitHub via the books product page, located at www.apress.com/9781484269688 . For more detailed information, please visit http://www.apress.com/source-code .

This book aims to be accessible to novices who have some basic working experience with computers, and at least some experience with programming. Knowing how to program is not a strict necessity, although it may help in grasping some concepts. The book also assumes some experience with high school mathematics, such as functions.

One of the reasons for writing this book is that I could not find a single book that explained how to implement blockchain from scratch, covering all the details. I had to do a lot of research on the Internet to come up with a complete picture of what blockchain is, how one can implement it, and what it is good for.

Since its easy to get sidetracked by the amount of information, every chapter contains a summary to serve as recall. Moving back and forth between chapters until information sticks can be useful in aiding understanding.

The recommended approach to the book is to follow along and write the code as its being explained instead of reading passively. This way you will get the most of it. All of the source code is available for download from https://github.com/bor0/racket-coin .

You can access my blog at https://bor0.wordpress.com and check out some of my latest work. Feel free to contact me at buritomath@gmail.com for any questions you might have, and I will do my best to answer.

Thanks to my family, coworkers, and friends for all the support they give to me.

Finally, thank you for purchasing this book! I hope that you will learn new techniques in reading this book and that it will spark more interest in Lisp and blockchain.

The blockchain bazaar, by D. Bozhinovski

This chapter introduces some important blockchain definitions and examples. We will see what properties a blockchain has, what it allows us to do, and what it is good for.

Definition 1-1

Blockchain is a system in which a record of transactions is maintained across several computers that are linked in a peer-to-peer network.

We will give an example that will serve as a motivation, as well as define what encryption and hashing techniques are and how can they help us with our system.

Note that we will hand-wave some of the technical bits in this chapter, as it serves as introductory material. The technical bits will be uncovered later when we start building the blockchain.

1.1 Motivation and Basic Definitions

Lets assume that you and your friends exchange money often, for example, when paying for dinner or drinks. It can be inconvenient to exchange cash all the time.

One possible solution is to keep records of all the bills that you and your friends have. This is called a ledger and is depicted in Figure .