The best book on the topic I've found. And I'm in fact hooked on the subject, so bear with that :) Here are my reasons:
1. The authors do a lot to carefully describe all the hard concepts one by one, in order, w/o getting bound to any particular implementation. This is not easy and twice or thrice I made a mental note that "I'm missing X here, if I were him/her, I would write about Y", but to my satisfaction, these deficiencies were always fixed in further chapters of the book.
2. I like the comparisons between traditional (centralized) and self-sovereign models - and the fact that the authors were transparent about challenges in front of SSI, BUT sometimes I missed more practical (that's the key word here, because there are many very theoretical ones) examples and indirect challenges (especially for governance and proofs).
3. Chapters 7 and 8 (the two most important ones) could use a bit more polish. I'm not sure everyone will comprehend them at the first read and they are crucial to understanding the whole book.
4. I think it would be good to create a new, separate chapter for "devil advocacy" - to deal with the common statements criticizing the concept of SSI.
5. My favorite chapters: 17 (parallels between identity and money), 3 and 5 (as they set a nice conceptual foundation for the whole book). My least favorite chapters: 19-24 as I don't think they add much to what's covered in 18 (explaining the value of SSI to the business)
In the end: highly recommended. I strongly believe that the concept of SSI will be extremely important in the future - that's actually one of the few implementations on the blockchain that make a lot of sense. Fortunately, this interesting topic has got a very good book - the one it deserves.
It’s a great book to take a systemic overview of the field, and to learn which topics are still immature enough to invest into their development. You shouldn’t expect to get a deep knowledge of some particular topic or answers how to get some practical solution. I’d say it’s more like a great question, that is 50% of the answer. I’d recommend to newcomers in the field to read it with caution. It seems to me that is not a great point to start, because it’s better to start with some particular example. The field and the general topic just hardly fits to our everyday expectation of how the things regarding the identity should be arranged. If I hadn’t had try to implement such solution myself and hadn’t hat got the feedback and questions from particular users, I wouldn’t have understood why some solutions are proposed or questions are raised.
Read Version 9 of the Early access book. Quite interesting topic.
Definitely learned some things about SSI. The more technical, first-principles-cy chapters were especially nice.
Other chapters left me feeling vaguely unsatisfied; big words and abstract concepts like ssi governance, lacking concrete examples. There, I can't tell if it's not just a giant tower of bullshit.
Some of the writings on history of SSI devolved into endless lists of "random" organizations dealing with SSI and the list of their founders. Contrast that with the chapter on the history of free Software/Open Source which actually had some meat to it and interesting context.
May update rating after reading the chapters not yet released.
This book is an example that one can describe a non-trivial topic in a really organized and detailed manner. It covers all the aspects of SSI, from Verified Credentials, through DIDs, Wallets and Agents till Governance. It has a lot of references to actual implementations. I like how authors covered the moon math of ZKP to show how it can be used to assert a given claim without revealing the actual secret.
Beside getting really deep with a good learning curve (the amount of knowledge I absorbed during this read is astonishing), there are also nontechnical parts. One of them, related to pitching and sharing the knowledge was quite intriguing as it's unusual to find a book that goes that deep into the selling part, especially when it's rooted in tech that deep. The other one, covering OSS and hammering the _libre software_ mantra was too religious/zealous. I do understand the concept of Wallet Wars and standards that should emerge, but at the same time we live in times of free OSS labour, which makes me wonder how it will play out.
The appendices part does not disappoint. Covering identity in Ethereum (with various ERCs), or others topics? They are all covered.
One could wish to read more books like this about the world changing technology.