Author: Tiana Laurence
Publisher: Wiley
Date: May 2019
Pages: 256
ISBN: 978-1119555018
Print: 1119555019
Kindle: B07QGHDQMV
Audience: Managers needing to sound convincing and other non-technical readers
Rating: 4.5
Reviewer: Alex Armstrong

The blockchain is still being hyped as the next revolution. Time for a second edition?

This really is a book for dummies - well if you interpret "dummy" as someone who wants to know all the words without understanding much. As a dummy you are most likely going to be thrown by the use of unexplained words like "hash" and "merkle tree" unless you just accept them as jargon. There is a diagram of a merkle tree, but little explanation of what it is or how it works. At a slightly less technical level the introductory chapters have a tendency to use terms such as the Byzantine General's problem and similar.

OK, this is all fine as you might not buy the book to find out how the blockchain works - just to find out why you keep hearing about it. The problem is that the book doesn't really distinguish between the different algorithms used in association with the blockchain and the basic idea of a blockchain. It claims that the blockchain solves the problem of who you can trust and this isn't true in any sense.

The blockchain solves two  problems. The first is that it provides a way to create a public ledger that cannot be modified without that modification being noticed. The reason is that the blocks are linked together by cryptographic hashes which depend on blocks earlier in the chain. Any changes to the earlier blocks become immediately obvious as the chain becomes inconsistent. Why is this important to know? Because it indicates the essential properties of the blockchain. The deeper into a chain a block becomes the more it is fixed and unchangeable because changing it means rebuilding and revalidating the chain from that point on.

The issue of trust isn't part of the blockchain's main algorithm, but part of the proof of work algorithm, which addresses the second problem regarding trust. While the blockchain doesn't prove that you can trust the person elected to validate the block. It does provide a trustworthy way of selecting that agent. The agent you select could be corrupt, but there is no way that any corrupt agents can manipulate the selection procedure so that they are certain to be selected to mal-administer the blockchain.

OK, that's the blockchain in a nutshell and this book doesn't do a good job of telling you this.

What the book does do is to give you some very rough ideas of what a blockchain is and then takes you through some examples.  Chapter 1 is an introduction to the ideas of the blockchain and in many ways this is about as technical as the book gets. Chapter 2 is about picking a blockchain and is a vague management guide. Chapter 3 tells you how to get a bitcoin, use a wallet and what a smart contract is. Its final few pages explain Ethereum.

Part 2 of the book is a tour of using different blockchains. Chapter 4 describes the Bitcoin blockchain, which is where it all started. From here we have chapters on Ethereum, Waves, Factom (the author's own company) and EOS. This selection has changed slightly from the first edition and this is a reflection of how fast moving, a.k.a unstable, the whole blockchain world is.

Then in Part 3 the tour continues with Hyperledger, Azure and IBM Bluemix. Each is more or less a user's guide rather than being deep and technical.

Part 4 of the book deals with application areas. We have chapters on financial technology, real estate, insurance and government and a final one on other smaller areas.

The final part will seem a little strange if you are not familiar with other books in the For Dummies series. Called The Part of Tens it consists of three chapters that each lists ten things - ten resources, ten rules and ten projects. This is part of the standard format and seems to work in this case. 

This is the sort of book you might buy and read if you were about to attend a meeting where you needed to sound as if you knew all about blockchain. It will give you all the jargon and it will introduce you to the best known blockchain implementations. This might be enough but don't buy this book if you are looking to understand the principles of the blockchain or how to implement innovative algorithms. This is targeted at management dummies rather than techie dummies.

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