title: Does jwt always uses same secret key for all the users?
body: <p>I was wondering, In subsequent request to server, client sends back the JWT token to server.
  And at server, server extract header and payload and some secret key which is already at the server, that way server reform the JWT and compare with the signature.
  So I was thinking how server identify which secret key to use to reform the JWT to test the incoming token from the client. Or it always uses the same secret key for all the clients?
  Or how where this green color secret comes from at the server?
  <a href="https://i.stack.imgur.com/801tT.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/801tT.png" alt="enter image description here" /></a></p>