title: JWT token for cross domain authentication
body: <p>I'm trying to create a simple SSO system in PHP for two domains which are thematically connected.</p>
  
  <p>So I was wondering if it is possible to store a signed JWT token containing user username from domain A to the local storage. And then to verify the JWT using the same secret key from a domain B which would lead to a successfull authentication.</p>
  
  <p>I've search google for some answers and I found some of them containing a middle authentication domain, which would take care of authentication. But I would like just to link the two domains I have.</p>
  
  <p>Thanks.</p>