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NIST SP 800-172 Enhanced CUI Protection Center

03.05.05E — Expiration of Cached Authenticators

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.

1Parameters
1Source controls
1Assessment objectives
3Assessment methods

03.05 — Identification and Authentication · NIST SP 800-172 Revision 3

Active
Official NIST requirement content

Security requirement

Prohibit the use of cached authenticators after [Organization-defined: time period].

Official NIST discussion

Discussion

Cached authenticators are used to authenticate to a local machine when the network is not available. If cached authentication information is out of date, the validity of the authentication information may be questionable. This requirement enhances SP 800-171 requirement 03.05.07.

Official organization-defined parameters

Tailoring decisions required

Resolve these values through the governing organization’s approved tailoring and risk-management process before declaring the requirement implemented.

time periodorganization-defined time periodthe time period after which the use of cached authenticators is prohibited is defined.
Official protection strategy classifications

Protection strategies supported

These classifications are carried from the official SP 800-172 OSCAL record and help explain the enhanced requirement’s defensive purpose.

PS-PRAPenetration-Resistant Architecture
Bare Metal Cyber interpretation

Implementation perspective

Treat Expiration of Cached Authenticators as an enhanced CUI protection outcome for elevated threat conditions 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 federal agency selected this enhanced requirement for the critical program or high-value asset and identify the CUI system components, services, users, and external connections in scope.
  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 critical-program or high-value-asset CUI, data flows, users, and services are protected by this enhanced 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 800-172A content

Assessment objectives and methods

Assessment objectives (1)
  1. the use of cached authenticators is prohibited after [Organization-defined: time period].

Examine

  • Identification and authentication policy
  • procedures addressing authenticator management
  • system security plan
  • system design documentation
  • system configuration settings and associated documentation
  • system audit records
  • other relevant documents or records

Interview

  • Personnel with authenticator management responsibilities
  • personnel with information security responsibilities
  • system/network administrators
  • system developers

Test

  • Mechanisms supporting and/or implementing authenticator management capabilities
Official source-control relationships

Source NIST SP 800-53 controls

These controls are referenced by the official SP 800-172 Rev. 3 OSCAL record. Open the corresponding control pages for complete control text, enhancements, D3FEND mappings, and related learning.

Source record

Authoritative sources