NTLM is an authentication protocol used in various Microsoft network protocol implementations and supported by the NTLM Security Support Provider ("NTLMSSP"). Originally used for authentication and negotiation of secure DCE/RPC, NTLM is also used throughout Microsoft's systems as an integrated single sign-on mechanism. . NTLM employs a challenge-response mechanism for authentication, in which clients are able to prove their identities without sending a password to the server. It consists of three messages, commonly referred to as Type 1 (negotiation), Type 2 (challenge) and Type 3 (authentication).
libntlm0-dev | Development files for the NTLM authentication library | Mehr ...
Libntlm is a library that implements Microsoft's NTLM authentication. This package contains all the files necessary for developing programs with NTLM support.