What Does Windows NT LAN Manager (NTLM) Mean?
Windows NT LAN Manager (NTLM) is a security protocol suite for Microsoft Windows NT 4.0. NTLM replaced Windows LAN Manager (LANMAN). NTLM is used for down-level client and server compatibility up to Windows 2000.
NTLM was replaced by Microsoft Kerberos.
Techopedia Explains Windows NT LAN Manager (NTLM)
NTLM authenticates clients and servers via a challenge-response method composed of three messages, as follows:
- Negotiation: Advertises capabilities
- Challenge: Establishes identity
- Authentication: Authenticates the client or server
NTLM uses one or more server-stored hashed passwords for authentication. Each password value is a 16-byte LM hash or NT hash. Microsoft does not recommend NTLM for current applications, due to weak encryption.