NTLM

NTLM, or NT Lan Manager, is an authentication protocol used by Microsoft systems to verify a user's identity. It allows users to log in to networks and access resources securely. NTLM works by encrypting user credentials and relies on a challenge-response mechanism; when a user tries to log in, the system asks for proof of identity without transmitting the actual password. While it was widely used in earlier Windows environments, NTLM has security weaknesses and has largely been replaced by more secure protocols like Kerberos in modern systems. However, it is still encountered in certain legacy systems.