Is JSON Web Token (JWT) the Best Choice for Session Management?

?? First, what is JWT? ??

JWT (JSON Web Token) is a way to securely transfer data between two parties (Server and Client). You can think of it as a data package ?? in JSON format, signed to verify that the information inside it comes from a trusted source.

??? How does it work?

In simple steps:

1?? When a user logs in to a website, the website creates a JWT and sends it to the server.

2?? The JWT contains user data, like their name, permissions, and role.

3?? The website sends the JWT with every request the user makes.

4?? The server verifies the JWT's signature to ensure it hasn't been tampered with. It then uses the data inside to confirm the user's identity and permissions.

5?? If the user is authorized, the server grants access to the requested resources.

?? Now, let's talk about the main drawbacks of using JWT

You might wonder, “But so many websites use it! How can it have drawbacks?” ??

?? Every tool has its limitations, and JWT is no exception. Understanding them helps us manage its use effectively.

1?? Large size ?? JWTs are much larger compared to traditional ?? cookies. For example, storing a simple user ID like user123 in a JWT takes up more space because of its structure (?? Header, ?? Payload, and ?? Signature).

2?? Duplicate signatures ?? Many frameworks already add a secure signature to cookies. Adding JWTs with their own signature inside cookie-based sessions creates unnecessary duplication without extra benefits.

3?? Fixed validity ?? Since JWTs are stateless tokens, they remain valid until they expire. This can lead to:

• Logout not invalidating the token.
• If a JWT is compromised, an attacker can use it until it expires.

4?? Outdated data ? JWTs don’t reflect changes made after their creation. For example, if a user’s permissions are updated, the JWT will still carry the old data until it expires. This can allow unauthorized access based on outdated roles.

5?? Security concerns ?? Most JWTs are signed but not encrypted, meaning anyone who has access to the JWT can easily read its content.

• Not using HTTPS makes JWTs vulnerable to attacks like ?? Man-in-the-Middle.

6?? Session management complexity ?? Managing sessions with JWT is tricky. Features like revoking tokens or updating permissions dynamically are hard to implement compared to traditional session methods.

?? Summary:

JWT is a powerful tool when used appropriately, such as for Stateless or One-Time Authorization scenarios. However, misuse—like using it for long sessions or storing sensitive data—can expose you to the challenges mentioned above.

?? How to handle it properly?

• Use short expiration times so tokens can be refreshed regularly, reducing the risk if compromised.
• Avoid storing sensitive or critical data inside JWTs.
• If you’re working in a Stateful system, consider more secure alternatives like Sessions or Cookies with CSRF Tokens.