Authentication helps you confirm the identity of users requesting access to your Web sites. IIS supports both challenge-based ...

Authentication helps you confirm the identity of users requesting access to your Web sites. IIS supports both challenge-based and login redirection-based authentication methods. Challenge-based authentication methods require clients to respond correctly to a server-initiated challenge. Login redirection-based authentication methods rely on redirection to a login page to determine the identity of the user. You cannot use both authentication methods at the same time. IIS also supports client certificate authentication, which requires configuring Secure Sockets Layer (SSL) for the site.