libntlm0 binary package in Ubuntu Xenial i386

 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).

Source package