Overview#Windows Integrated Authentication (WIA) or Integrated Windows Authentication (IWA) are a terms associated with Microsoft products that refers to the SPNEGO, Kerberos, and NTLM SSP authentication protocols with respect to SSPI functionality introduced with Microsoft Windows 2000 and included with later Windows NT-based operating systems. The term is used more commonly for the automatically authenticated connections between Microsoft Internet Information Services, Internet Explorer, and other Microsoft Active Directory aware applications.
With Integrated Windows authentication (formerly called NTLM, and also known as Windows NT Challenge/Response authentication), the user name and password (credentials) are hashed before being sent across the network. When you enable Integrated Windows Authentication, the client browser proves its knowledge of the password through a cryptographic exchange with your Web server, involving hashing.
Windows Integrated Authentication is an Authentication Agent for Windows Operating Systems.