Master secure signing, encryption and token handling in your Java applications with JOSE. With this book, discover how to implement JWS, JWE, JWK, and JWT to build authentication and authorization systems that are scalable, interoperable and secure in real-world environments.

You’ll explore JOSE from the ground up, beginning with core concepts such as cryptography, token structure, and validation logic. Through clear examples and step‑by‑step code, the book teaches you how to issue, parse, validate, encrypt, and decrypt tokens using Java’s standard APIs and widely adopted JOSE libraries. You’ll learn why vulnerabilities often stem not from broken cryptography but from incorrect validation, unsafe defaults, key mismanagement, and misunderstanding of claims. You’ll learn to avoid common pitfalls and errors by designing and reviewing tokens with security correctness in mind.

This book bridges the gap between JOSE specifications and real Java implementations used in APIs, microservices, OAuth 2.0, and OpenID Connect systems. It draws on security audits, production failures, and enterprise requirements to show how JOSE breaks in practice and how to build defenses that last.

What You Will Learn: 

• Correctly issue, parse, and validate JWTs in Java applications
• Choose between JWS and JWE based on concrete confidentiality and integrity needs
• Implement secure claim validation, including issuer, audience, expiration, and replay checks
• Manage cryptographic keys using JWKs, including rotation, lifecycle management, and safe storage
• Debug and analyze token failures in real production environments using structured techniques
• Identify and avoid common JOSE vulnerabilities, including algorithm confusion and unsafe defaults

Who This Book is for: 

Backend Java developers, platform engineers and software architects working on APIs or distributed systems.

Shahid Salim is a senior Java and security engineer with 25 years of extensive hands-on experience designing, implementing, and reviewing secure authentication and authorization systems using JWT, OAuth 2.0, and JOSE standards. He has worked on enterprise Java and microservice architectures where correct cryptographic usage, token validation, and key management are critical for security, compliance, and long-term maintainability.

Across multiple projects, he has encountered recurring JWT and JOSE vulnerabilities—such as algorithm confusion, incomplete claim validation, improper key rotation, and overreliance on framework defaults, even in experienced engineering teams. This book is shaped by those real-world failure modes and focuses on explaining not only how JOSE works, but why certain implementation choices are dangerous and how to avoid them.

He also brings an enterprise and regulatory perspective to the topic, including practical alignment with OAuth 2.0, OpenID Connect, and eIDAS requirements, which is rarely addressed in typical JWT-focused books.