Nokia Check Point Nokia Siemens Networks IKEv2 specifies that EAP authentication must be used together with public key signature based responder authentication. This is necessary with old EAP methods that provide only unilateral authentication using, e.g., one-time passwords or token cards. This document specifies how EAP methods that provide mutual authentication and key agreement can be used to provide extensible responder authentication for IKEv2 based on methods other than public key signatures.