Can you share your experience using JSON Web Tokens in projects?

In PHP projects, I used JSON Web Tokens (JWT) for implementing user authentication and authorization. JWT allows transmitting user information in an encrypted form between the client and server without the need to store sessions on the server.

Main steps for using JWT:

1. Upon successful authentication, the user receives a JWT containing payload data (e.g., user ID, roles).
2. The token is signed with a secret key to prevent forgery.
3. The client stores the token (e.g., in localStorage) and sends it in the Authorization header for subsequent requests.
4. The server verifies the token's signature and extracts data to determine access rights.

Example of creating a JWT using the firebase/php-jwt library:

use Firebase\JWT\JWT;

$payload = [
    'iss' => 'your-domain.com',
    'iat' => time(),
    'exp' => time() + 3600, // validity period of 1 hour
    'userId' => 123
];

$jwt = JWT::encode($payload, $secretKey, 'HS256');

// For verification:
$decoded = JWT::decode($jwt, $secretKey, ['HS256']);

Using JWT simplifies application scaling, as it does not require storing sessions on the server, but it is important to properly configure the token's expiration time and handle its renewal.