This second part of the Stateless Spring Security series is about exploring means of authentication in a stateless way. If you missed the first part about CSRF you can find it here. So when talking about Authentication, its all about having the client identify itself to the server in a verifiable manner. Typically this start with the server providing the client with a challenge, like a request to fill in a username / password. Today I want to focus on what happens after passing such initial (manual) challenge and how to deal with automatic re-authentication of futher HTTP requests.