NIST SP 800-171 Rev. 3 3.5.11 — Authentication Feedback

What this control requires

This control requires obscuring feedback of authentication information during the authentication process to prevent unauthorized individuals from compromising authentication mechanisms. It includes measures like displaying asterisks for passwords or limiting the visibility of authentication feedback to reduce the risk of shoulder surfing. This control supports the Authentication Feedback Mechanism capability within the Identification and Authentication (3.5) family.

In plain English

This control requires obscuring feedback of authentication information during the authentication process to prevent unauthorized individuals from compromising authentication mechanisms. In practice, this means you can prove you information management-level controls on a defined cadence.

Why it matters

DoD contractors and their subcontractors must implement all 100 SP 800-171 requirements to keep CUI handling contracts. Gaps are scored against the SPRS scoring methodology; below a 110-point starting score, each unmet requirement deducts points and a below-threshold score can disqualify a bid.

What an auditor looks for

A C3PAO conducting a CMMC Level 2 assessment uses NIST SP 800-171A objectives. They expect a System Security Plan (SSP), Plan of Action & Milestones (POA&M) for any gaps, and objective evidence (configurations, ticket records, training records) for every requirement.

Within Identification and Authentication, the assessor will trace your implementation back to the catalogue reference (Requirement 3.5.11) and look for objective evidence on the latest two assessment cycles.

How to implement

Policy Management

Docs. Keep each policy in version-controlled Markdown alongside the code that implements it; ship a signed PDF snapshot at each annual review and link the SHA into the SoA.

Operational checklist

• Information. Document the trigger, the owner and the cadence.
• Authentication. Document the trigger, the owner and the cadence.
• Risk. Document the trigger, the owner and the cadence.
• Policy. Document the trigger, the owner and the cadence.
• Scope: management, authentication, feedback, passwords, individuals.

Evidence to collect

• Policy Document. A signed and version-controlled policy / standard / procedure document.

Signed policy or standard documents the safeguard. Focus: Authentication Feedback.

Common pitfalls

• Policies that no engineer has read; the version in Confluence drifts from the version that's actually being enforced.

How it maps to other frameworks

Computed from shared tags, control component and key-operation subjects — handy when you are reconciling controls across an audit.

• ISO/IEC 27001:2022 A.5.17 — Authentication information
• NIST SP 800-53 Rev. 5 IA-8(4) — Use Of Defined Profiles
• HIPAA (45 CFR Part 164) 164.524(e) — Documentation
• SOC 2 (2017 TSC) CC2.3 — External Communication on Internal Control Matters

Related controls in NIST SP 800-171 Rev. 3

• Requirement 3.5.12 — Authenticator Management
• Requirement 3.5.5 — Identifier Management
• Requirement 3.5.7 — Password Management
• Requirement 3.1.10 — Device Lock
• Requirement 3.5.1 — User Identification and Authentication
• Requirement 3.13.15 — Session Authenticity

References

• NIST Computer Security Resource Center — NIST SP 800-171 Rev. 3
• Catalogue identifier: Requirement 3.5.11

Topics: governance riskidentity managementpolicy management