NTLM Last modified: Monday, October 20, 2008
Abbreviation for "Windows NT LAN Manager" The NTLM protocol was the default for network authentication in the Windows NT 4.0 operating system. It is retained in Windows 2000 for compatibility with down-level clients and servers. NTLM is also used to authenticate logons to standalone computers with Windows 2000. Computers with Windows 3.11, Windows 95, Windows 98, or Windows NT 4.0 will use the NTLM protocol for network authentication in Windows 2000 domains. Computers running Windows 2000 will use NTLM when authenticating to servers with Windows NT 4.0 and when accessing resources in Windows NT 4.0 domains.* NTLM uses 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). The protocol continues to be supported in Windows 2000 but has been replaced by Microsoft Kerberos as the default/standard. * [ Source: Microsoft Knowledge Base]
•E-mail this definition to a colleague• For internet.com pages about NTLM . Also check out the following links! Microsoft home page  The Microsoft home page hosts a collection of company news articles, as well as links to product information, training, support, free software, events, and company information. The NTLM Authentication Protocol  This article seeks to describe NTLM at an intermediate to advanced level of detail, suitable as a reference for implementers. Webopedia's "Did You Know...?" Section  Use this Webopedia knowledge section for an in-depth overview of specific technologies and occurrences in the areas of Computer Science, The Internet, and Computer Hardware and Software.	Network Protocols Networks Security Standards communications protocol handshaking LAN Give Us Your Feedback PDAs paLM Products Shop by Top Models: Palm Zire™ Handheld 1 store offers from $180 - $180 Palm m500 Handheld 1 store offers from $40 - $40 Palm Tungsten E2 Handheld 1 store offers from $570 - $570 Palm m505 Handheld 1 store offers from $390 - $390 Palm T|X Handheld 1 store offers from $550 - $550