NIST 800-171, a publication by the National Institute of Standards and Technology, focuses on protecting Controlled Unclassified Information (CUI) in nonfederal information systems. One critical aspect covered in NIST 800-171 is identification and authentication, which ensures only authorized users and devices access these systems.

There are three main requirements within NIST 800-171 regarding identification and authentication. First, organizations must assign unique identifiers to users, processes acting on behalf of users (like automated tasks), and devices. This helps track activity and prevent unauthorized access. Second, organizations must implement methods to verify the identities of users and devices before granting access to CUI systems. This verification process, often called authentication, typically involves credentials like usernames and passwords.

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Finally, NIST 800-171 emphasizes the importance of multi-factor authentication (MFA). MFA adds an extra layer of security by requiring users to provide more than one piece of evidence to verify their identity. This could be a combination of something the user knows (password), something the user has (security token), or something the user is (fingerprint). By requiring MFA, organizations make it significantly harder for unauthorized individuals to gain access to CUI, even if they steal a password.