JSON Web Tokens (JWT): Deep Dive into Design, Security Risks and Real-World Failures

JWT (JSON Web Tokens) have become a default choice for authentication and authorisation in modern systems. They are widely adopted because they are: Stateless Scalable Easy to integrate across services But in real-world environments, especially distributed systems, JWT often introduces subtle security risks that are not immediately visible. Most JWT implementations are cryptographically correct… but architecturally flawed. This post explains: How JWT actually works Where implementations go wrong