Book
Hajimete no Digital Identity (Getting Started with Digital Identity)
Authentication, Authorization, and Identity Management Every Web Service Needs
Ryo Ito
Summary
A Japanese-language guide to digital identity management by Ryo Ito, aimed at IT engineers who develop and operate online services without a specialized background in digital identity. Its premise: building a service is inseparable from managing digital identity, and treating authentication apart from a service's overall identity management invites operational problems and security oversights even as passkeys and OIDC draw attention. Rather than treating signup, login, logout, account recovery, and account closure as separate features, the book frames them as one identity lifecycle, arguing this lowers security risk and improves user experience. It builds from that view, starting with identity verification and authentication, then covering authentication methods, identity federation, and ID-management technologies, in plain language for readers new to the subject.
Target Readers
- Engineers involved in designing web services or apps, who need identity management treated as a whole system rather than a collection of separate features
- Service developers who implemented authentication as a stopgap and want to revisit it as part of a proper identity lifecycle before it causes operational or security problems
- People commissioning a system that includes authentication, who need enough grounding in identity management to evaluate what they're asking for
Tags
Colophon
- Publisher
- Gijutsu-Hyohron
- ISBN
- 978-4-297-15376-2
- Published
- Jan 2026
- List price
- ¥2,420incl. taxMay differ from the actual selling price on Amazon
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Prerequisites
- Recommended
Ango Gijutsu Nyumon, 3rd Edition (An Introduction to Cryptography)
Alice in the Land of Secrets
Hiroshi Yuki
Reason: With hashing and signatures as your cryptographic foundation, see how they play out across a real identity lifecycle. This book traces registration through login, recovery, and account closure as one continuous flow, moving from single-service authentication/authorization to identity-provider federation.
Next Books
- Recommended
OpenID Connect Nyumon (Introduction to OpenID Connect)
Practical Technical Guide for Application Developers
Kohei Toki
Reason: Grasping the whole picture of ID management—from signup to logout to identity federation—in plain language lays the groundwork for the more specialized, detailed implementation covered by the OAuth 2.0 and OIDC protocol specs. Having organized the relationships among identity verification, authentication, and session management in Getting Started with Digital Identity makes it easier to place the authorization code flow and token validation covered in Introduction to OpenID Connect.
- Recommended
OAuth 2 in Action
Justin Richer, Antonio Sanso
Reason: Once you hold the shape of ID management and identity federation, step into the implementation of the authorization protocol at its core. Working through OAuth 2.0's grants and flows in code clarifies pitfalls like token leakage and redirect URI tampering from first principles.