Extensible Authentication Protocol

Extensible Authentication Protocol (EAP) is an authentication framework included in Windows Client and Windows Server operating systems. EAP in Windows includes many authentication protocols for network access authentication when you deploy dial-up, virtual private network (VPN), 802.1X wireless, and 802.1X wired technologies using Network Policy Server (NPS), Routing and Remote Access Service (RRAS), or both.

EAP includes password-based authentication methods and more secure certificate-based authentication methods that you can use if you deploy a public key infrastructure with Active Directory Certificate Services or other public or private certification authorities.

EAP includes Protected EAP (PEAP) and is extensible because it allows developers to create new authentication types that you can plug in to your existing EAP deployment.

Note: In Windows Server 2003, Network Policy Server was named Internet Authentication Service.