𝗝𝗪𝗧 𝗧𝗼𝗸𝗲𝗻𝘀 𝗦𝗲𝗰𝘂𝗿𝗶𝘁𝘆 𝗚𝘂𝗶𝗱𝗲

𝗝𝗪𝗧 𝗧𝗼𝗸𝗲𝗻𝘀 𝗦𝗲𝗰𝘂𝗿𝗶𝘁𝘆 𝗚𝘂𝗶𝗱𝗲

Many developers use JWTs wrong. This leads to security leaks. Learn how to use them safely.

A JWT is encoded JSON. It has a digital signature. It is not an encrypted vault. Anyone who sees the token reads the contents. The signature proves the data is not changed.

JWTs have three parts:

• Header: Sets the algorithm.
• Payload: Holds user ID and roles.
• Signature: Checks for tampering.

The flow is simple:

• You log in.
• Server sends a signed JWT.
• You store it in a cookie.
• You send it with every request.
• Server checks the signature.

This removes the need for database lookups. This makes your app fast.

JWTs are stateless. This makes them hard to cancel. Fix this with these steps:

• Set short expiry times.
• Use refresh tokens for new access.
• Block revoked IDs in Redis.

Follow these security rules:

• Always verify the signature first.
• Keep tokens short lived.
• Use httpOnly cookies to block XSS attacks.
• Keep secrets out of the payload.
• Use RS256 for production systems.
• Check expiry and audience claims.

Pick the right algorithm:

• HS256: Simple apps.
• RS256: Microservices.
• ES256: Performance apps.

Remember these points:

• JWTs are signed, not encrypted.
• Store tokens in httpOnly cookies.
• Validate signatures on the server.
• Rotate refresh tokens.

Source: https://dev.to/moksh/jwt-tokens-security-guide-what-every-developer-must-know-4gh9