13 Jul 2026CMMC Phase II suspended: no C3PAO assessments can be designated. DFARS 7012 and Rev 2 still apply.What changed, and what did not

NIST SP 800-171 Rev 2 · 3.5 Identification & Authentication

3.5.4 Replay-resistant authentication

Employ replay-resistant authentication mechanisms for network access to privileged and non-privileged accounts.
SPRS weight
1
1 point deducted from 110 when not implemented.
CMMC level
L2
Level 2 only; not among the 17 Level 1 practices.
Assessment objectives
1
From NIST SP 800-171A, each one a “determine if” an assessor answers.

What an assessor checks

NIST SP 800-171A breaks 3.5.4 into 1 objectives. Every one has to be met for the requirement to be met; a partial answer scores as not implemented.

  1. Determine if replay-resistant authentication mechanisms are implemented for all network account access to privileged and non-privileged accounts.
Examine
[SELECT FROM: Identification and authentication policy; procedures addressing user identification and authentication; security plan; system design documentation; system configuration settings and associated documentation; system audit logs and records; list of privileged system accounts; other relevant documents or records].
Interview
[SELECT FROM: Personnel with system operations responsibilities; personnel with account management responsibilities; personnel with information security responsibilities; system or network administrators; system developers].
Test
[SELECT FROM: Mechanisms supporting or implementing identification and authentication capability or replay resistant authentication mechanisms].

If it is open: POA&M eligibility

May be carried on a Level 2 POA&M · 1 point deducted

A 1-point requirement outside the six named exclusions - eligible to carry, and NOT MET until a closeout assessment confirms it.

A POA&M is only permitted at a score of 88 or above, and closes in one 180-day window. Check a full gap list or compute your score.

Where 3.5.4 maps

NIST SP 800-53 Rev 5

  • IA-7 Cryptographic Module Authentication
  • SC-23 Session Authenticity

NIST CSF 2.0

  • Authentication is managed

SOC 2

No direct mapping.

Query it from your own tools

This page and the MacTech CMMC MCP server render the same dataset. Ask your assistant and it will answer from the methodology, not from memory.

lookup_control 3.5.4
get_assessment_objectives 3.5.4
generate_poam_entries ["3.5.4"]

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From MacZine

Working notes on Identification & Authentication

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