What are different Authentication Protocols available in Windows Server 2003?

Windows Server 2003 provides the ability to authenticate a variety of client operating systems. Because client operating systems support various levels of authentication protocols, Windows Server 2003 supports two primary authentication protocols: NTLM and Kerberos.
The NTLM authentication protocol uses a challenge-response mechanism to authenticate users and computers running Windows Me and earlier operating systems, or computers running Windows 2000 or later that are not part of a domain. A user is prompted (the challenge) to provide some private piece of information unique to the user (the response). Windows Server 2003 supports the following three methods of challengeresponse authentication:
LAN Manager (LM). Developed jointly by IBM and Microsoft for use in OS2 and Windows for Workgroups, Windows 95, Windows 98, and Windows Me. It is the least secure form of challenge-response authentication because it is susceptible to eavesdropping attacks, and servers that authenticate users with LM authentication must store credentials in an LMHash.
NTLM version 1. A more secure form of challenge-response authentication than LM. It is used for connecting to servers running Windows NT with Service Pack 3 or earlier. NTLMv1 uses 56-bit encryption to secure the protocol. Servers that authenticate users with any version of NTLM authentication must store credentials in an NT Hash.
NTLM version 2. The most secure form of challenge-response authentication available. This version includes a secure channel to protect the authentication process. It is used for connecting to servers running Windows 2000, Windows XP, and Windows NT with Service Pack 4 or higher. NTLMv2 uses 128-bit encryption to secure the protocol.
Kerberos is the default authentication protocol for Windows Server 2003, Windows 2000, and Windows XP Professional. Kerberos is designed to be more secure and scalable than NTLM across large, diverse networks.