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NIST SP 800-171 CUI Protection Center

03.05.04 — Replay-Resistant Authentication

Read the official CUI requirement and assessment content, then use the separately labeled Bare Metal Cyber perspective to connect it to implementation, evidence, and sustained operation.

1Source controls
2Assessment objectives
3Assessment methods

03.05 — Identification and Authentication · NIST SP 800-171 Revision 3

Active
Official NIST requirement content

Security requirement

Implement replay-resistant authentication mechanisms for access to privileged and non-privileged accounts.

Official NIST discussion

Discussion

Authentication processes resist replay attacks if it is impractical to successfully authenticate by recording or replaying previous authentication messages. Replay-resistant techniques include protocols that use nonces or challenges, such as time synchronous or challenge-response one-time authenticators.

Bare Metal Cyber interpretation

Implementation perspective

Treat Replay-Resistant Authentication as a CUI protection outcome that must be reflected in the system boundary, documented implementation, operational behavior, and assessment evidence. Pay particular attention to identity proofing, authentication strength, authenticator lifecycle, and resistance to credential compromise.

  1. Confirm the requirement is in scope for the CUI system components, services, users, and external connections being assessed.
  2. Resolve every organization-defined parameter through an approved governance and tailoring process.
  3. Map each clause of the requirement to an accountable owner, implementation mechanism, and evidence source.
  4. Verify that inherited and shared implementations are supported by current provider evidence and responsibility boundaries.
  5. Collect evidence during normal operation and review changes, exceptions, and deficiencies on a risk-based cadence.

Questions to ask

  • Which CUI assets, data flows, users, and services are protected by this requirement?
  • Which portions are implemented locally, inherited, shared, or not applicable, and what evidence supports that determination?
  • Do the system security plan, deployed configuration, operating process, and assessment evidence tell the same story?
  • What change, incident, or threshold should trigger reassessment?

Evidence and validation

  • identity proofing records
  • authenticator issuance and revocation logs
  • MFA and federation configuration
  • credential inventories and rotation evidence

Common failure patterns

  • MFA applied only to interactive users
  • service credentials without ownership or rotation
  • weak recovery paths that bypass strong authentication
  • federated trust not reviewed after partner changes
Official NIST SP 800-171A content

Assessment objectives and methods

Assessment objectives (2)
  1. SR-03.5.4.

    replay-resistant authentication mechanisms for access to privileged accounts are implemented.

  2. SR-03.5.4.

    replay-resistant authentication mechanisms for access to non-privileged accounts are implemented.

Examine

  • identification and authentication policy and procedures
  • system design documentation
  • system audit records
  • system configuration settings
  • list of privileged system accounts
  • system security plan
  • other relevant documents or records

Interview

  • personnel with system operations responsibilities
  • personnel with account management responsibilities
  • personnel with information security responsibilities
  • system developers
  • system administrators

Test

  • mechanisms for supporting or implementing identification and authentication capabilities
  • mechanisms for supporting or implementing replay-resistance
Official source-control relationships

Source NIST SP 800-53 controls

These controls are referenced by the official SP 800-171 Rev. 3 OSCAL record. Open the corresponding control pages for complete control text, enhancements, D3FEND mappings, and related learning.

Source controlIA-2(8)Open SP 800-53 control →
Source record

Authoritative sources

Bare Metal Cyber is an independent educational publisher and is not affiliated with or endorsed by NIST. The official publications, the responsible federal agency, and the governing contract or agreement determine applicability, tailoring, assessment depth, and required implementation.