I found this book very disappointing. Two out of the four glowing reviews in the 'product description' are not for this book, but for Dominic Frisby's seemingly better received book: Life After the State.
If you want a rather rambling journey through the characters involved in starting up cryptocurrencies, including a somewhat lengthy discourse on who the creater of Bitcoin was (or is!), then the book might be of some interest. If you really care who Satoshi Nakomoto is, and there is a complete appendix devoted to the issue, then there will probably be something of interest (it clearly became a bit of an obsession for Dominic Frisby).
However, if you are interested in Bitcoin, the currency itself, and for learning about what it is and how it works then this is not the book for you. If you are just happy to learn that Bitcoin is outside state control and somehow relies on a block chain to ensure security and uses complicated puzzles to mine new bitcoins, then fine; if it's just the personalities that interest you, you'll probably enjoy this book.
If you instead want some decent explanation of how Bitcoin actually works, how a block chain works in practice, how new bitcoins are actually mined, how security is guaranteed in practice, etc etc so you can actually start to understand cryptocurrences and take an informed view on their future, then look elsewhere. Dominic Frisby does write about the future of currencies and cryptocurrencies, but without the bedrock of being able to understand the mechanism of how cryptocurrencies actually work, one can't appreciate whether his predictions and observations have any sort of grounding in reality.
It is pretty clear that Dominic Frisby doesn't actually know much about the mechanics of Bitcoin. If he wanted to concentrate on personalities, he could have relegated some of the currency details to an appendix or appendices which just aren't there. Instead, in chapter one, we are told that bitcoins are mined by finding "the answer to a complex mathematical puzzle" along with many other simplified explanations that end up actually explaining nothing. In the acknowledgments, Dominic Frisby mentions that "the world of computer programming and cryptography was new to me six months ago..." and it shows. At the end of chapter one we are told "Well Done. You've just finished the hardest chapter in the book." Well, I would suggest that most people don't like being patronised. The patronising is all the worse because complicated detail just isn't there! I know no more about cryptocurrencies than I did when I started the book, and that was very little indeed.
I wasn't looking for a mathematical textbook on cryptography and cryptocurrencies, but I was really hoping for a book that would actually explain how Bitcoin and cryptocurrencies actually exist and work in practice. If you are hoping for the same, look elsewhere.