How to secure a REST API using JWT authentication

REST APIs, known for their logical simplicity and cohesive resource management, face security challenges, particularly when it comes to maintaining user authentication states. A powerful solution is the use of JSON Web Tokens (JWT), which allows secure representation of user identities without transmitting private credentials repeatedly. The process involves a client app sending credentials to an API, which verifies them and returns a signed JWT to the client. This token, structured into a header, payload, and signature, is used for subsequent requests, ensuring continued authentication without resending credentials. The article illustrates a practical example with a payroll API, emphasizing the role-based access control and the benefits of using algorithms like HS256 for encoding. While JWTs enhance security, the article advises that they should be part of a broader security strategy, including HTTPS, to effectively safeguard APIs from potential breaches.