Most banking sites I've seen use a sign in process that is proprietary, or otherwise won't integrate with an external IDP.
Should banks offer integration with services like OpenID, WS-Fed, or Persona systems?
Should a bank use those technologies (WS-Fed, Persona, or OpenID) even if they are "closed" and not federated with 3rd parties?
My desire for this is because they can offer multi factor authentication services even if the target web app doesn't support multi factor.
If a bank supported such a scheme, would a second challenge be useful / appropriate? (Password, OTP, Etc)