The Foreword is by Identity luminary (and friend) Kim Cameron and if I’m keeping it real, rather than describe the book’s contents, I wish he’d shared more thoughts around the problem space, the approach to the solution and the roadmap BEYOND cardspace. Here’s Kim’s take on the book [LINK].
The book itself is an easy read. Not a tome by an means. Easy to pickup as a reference or to sit with and read chapter by chapter.
It succeeds at describing Identity Federation from a conceptual level as well as from a technical level (as it pertains to Cardspace). It even addresses some of the less obvious issues such as the notion of auditing and non-auditing IdPs.
Be warned, this book focuses on Cardspace fairly exclusively. There isn’t a lot on interoperability here between things like OpenID and Cardspace for example. That’s a topic for another book and could not easily be incorporated without devoting a lot of pages to OpenID.
The technical section is navigated through use cases that tackle things from an end-user experience as well as from the developer angle. This is effective as often it’s hard to understand one without the other. At every point the reasoning behind the solution is presented also. This worked well.
For me personally, I wish they’d spent a little more time on things like GetToken() although using this directly will likely not be of interest to 90% of folks out there.
Unique to books of this type is a section devoted to Practical Considerations. Why one would want to setup an IdP or simply play the role of Identity Consumer for example. In today’s environment the business value of establishing yourself as an IdP is questionable and I was glad to see this point addressed head on.
Vittorio, Garrett and Caleb have done an terrific job of describing and grounding one of the most compelling and abstract problems faced by the internet today. This an excellent book and for many will serve as a one-stop-shop for all your Cardspace questions.