Plan-execute-verify on NIST SP 800-63B password rules, current revision

The current revision is NIST SP 800-63B-4. I read it at https://pages.nist.gov/800-63-4/sp800-63b.html. The page is dated "Tue, 26 Aug 2025", and its abstract says "This publication supersedes NIST Special Publication (SP) 800-63B." I searched the page for "draft", and the only hits were references to other documents, so this is not a public draft. The CSRC publication page (https://csrc.nist.gov/pubs/sp/800/63/b/4/final) returned a 404, so I couldn't check the revision status there. I didn't open the older Rev 3 page, so I make no claims comparing the two.

All password requirements are in Sec. 3.1.1.2, "Password Verifiers", on https://pages.nist.gov/800-63-4/sp800-63b.html:

• Single-factor minimum length: SHALL, 15 characters. The same item says verifiers MAY allow shorter passwords that are only used in multi-factor authentication, but SHALL still require at least eight characters.
• Maximum length: SHOULD, at least 64 characters. Verifiers should permit passwords of at least this length.
• Composition rules: SHALL NOT. Verifiers must not require mixes of character types.
• Periodic change: SHALL NOT. However, verifiers SHALL force a change if there is evidence of compromise.
• Password hints: SHALL NOT. Hints that unauthenticated claimants can see are not allowed.
• Security questions: SHALL NOT. Verifiers must not prompt for knowledge-based authentication or security questions when a password is chosen.
• Blocklist: SHALL. Verifiers must compare a new password against a blocklist of commonly used, expected or compromised passwords. They must compare the whole password and give the reason for any rejection.
• Password managers: SHALL. Verifiers must allow password managers and autofill. They SHOULD also allow pasting.
• Salt length: SHALL, at least 32 bits.
• Hashing scheme: SHOULD, not SHALL as the plan expected. The page says an approved scheme from the latest revision of SP 800-132 (or updated NIST guidance) "SHOULD be used". The separate rule that passwords be salted and hashed with a "suitable" scheme is a SHALL.

{"answers":[
{"topic":"single-factor-minimum-length","keyword":"SHALL","value":"15","quote":"Verifiers and CSPs SHALL require passwords that are used as a single-factor authentication mechanism to be a minimum of 15 characters in length.","url":"https://pages.nist.gov/800-63-4/sp800-63b.html"},
{"topic":"maximum-length","keyword":"SHOULD","value":"64","quote":"Verifiers and CSPs SHOULD permit a maximum password length of at least 64 characters.","url":"https://pages.nist.gov/800-63-4/sp800-63b.html"},
{"topic":"composition-rules","keyword":"SHALL NOT","value":null,"quote":"Verifiers and CSPs SHALL NOT impose other composition rules (e.g., requiring mixtures of different character types) for passwords.","url":"https://pages.nist.gov/800-63-4/sp800-63b.html"},
{"topic":"periodic-change","keyword":"SHALL NOT","value":null,"quote":"Verifiers and CSPs SHALL NOT require subscribers to change passwords periodically.","url":"https://pages.nist.gov/800-63-4/sp800-63b.html"},
{"topic":"password-hints","keyword":"SHALL NOT","value":null,"quote":"Verifiers and CSPs SHALL NOT permit the subscriber to store a hint (e.g., a reminder of how the password was created) that is accessible to an unauthenticated claimant.","url":"https://pages.nist.gov/800-63-4/sp800-63b.html"},
{"topic":"security-questions","keyword":"SHALL NOT","value":null,"quote":"Verifiers and CSPs SHALL NOT prompt subscribers to use knowledge-based authentication (KBA)","url":"https://pages.nist.gov/800-63-4/sp800-63b.html"},
{"topic":"blocklist","keyword":"SHALL","value":null,"quote":"When processing a request to establish or change a password, verifiers SHALL compare the prospective secret against a blocklist that contains known commonly used, expected, or compromised passwords.","url":"https://pages.nist.gov/800-63-4/sp800-63b.html"},
{"topic":"password-managers","keyword":"SHALL","value":null,"quote":"Verifiers SHALL allow the use of password managers and autofill functionality.","url":"https://pages.nist.gov/800-63-4/sp800-63b.html"},
{"topic":"salt-length","keyword":"SHALL","value":"32","quote":"The salt SHALL be at least 32 bits in length and chosen to minimize salt value collisions among stored hashes","url":"https://pages.nist.gov/800-63-4/sp800-63b.html"},
{"topic":"hashing-scheme","keyword":"SHOULD","value":null,"quote":"An approved password hashing scheme published in the latest revision of [SP800-132] or updated NIST guidelines on password hashing schemes SHOULD be used.","url":"https://pages.nist.gov/800-63-4/sp800-63b.html"}
]}