What are the reasons for increased security when using JWT tokens compared to other authentication methods?

JWT (JSON Web Token) provides enhanced security for several reasons:

• Token signature: JWT is signed using a secret key (HMAC) or a pair of keys (RSA, ECDSA), which guarantees the integrity and authenticity of the token. This prevents token forgery.
• No server-side state: The server does not store sessions, reducing risks associated with session data leaks or theft.
• Embedded data: JWT contains useful information (claims), such as user ID and expiration time, allowing quick rights verification without additional database queries.
• Expiration control: The token specifies a lifetime (exp), after which it becomes invalid.

Example of using JWT in Python with the PyJWT library:

import jwt
import datetime

secret = 'my_secret_key'
payload = {
    'user_id': 123,
    'exp': datetime.datetime.utcnow() + datetime.timedelta(hours=1)
}
token = jwt.encode(payload, secret, algorithm='HS256')

# Token verification
try:
    data = jwt.decode(token, secret, algorithms=['HS256'])
    print('User:', data['user_id'])
except jwt.ExpiredSignatureError:
    print('Token has expired')
except jwt.InvalidTokenError:
    print('Invalid token')

Thus, JWT provides a secure, self-sufficient, and scalable way of authentication.