NTLMSSP


NTLMSSP is a binary messaging protocol used by the Microsoft Security Support Provider Interface to facilitate NTLM challenge-response authentication and to negotiate integrity and confidentiality options. NTLMSSP is used wherever SSPI authentication is used including Server Message Block / CIFS extended security authentication, HTTP Negotiate authentication and MSRPC services.
The NTLMSSP and NTLM challenge-response protocol have been documented in Microsoft's Open Protocol Specification.