【Temporarily reduced price. Will return to original price soon.】 Thank you for viewing. This is a set of 3 books from Auth-ya's Atmosphere OAuth series. I am selling these because I have finished the Information Security Specialist examination. This is a set of 3 books. They are not sold separately. ◎ A book that helps engineers who are using OAuth2.0 in a casual way to organize and learn OAuth2.0 by doing hands-on exercises. ◎ A book that helps you organize and understand the differences between OAuth, OAuth authentication, and OpenID Connect. ◎ A book that helps you organize and understand attacks and countermeasures against OAuth/OIDC (Redirect Attack Edition)