Mapped to NIST 800-171 Requirement: 3.5.3
CMMC Assessment Objective: IA.L2-3.5.3[d]
What This Objective Means
This final assessment check in the series confirms whether replay-resistant authentication mechanisms are truly implemented and working across all applicable accounts and systems.
It brings together everything from:
• Account identification (3.5.3[a])
• Policy enforcement (3.5.3[b])
• Configuration (3.5.3[c])
Now, you need to demonstrate that the implementation is operational and enforced consistently in live environments—not just planned or partially deployed.
Why It Matters
Without confirming implementation:
• Controls may be incomplete or silently failing
• Users may bypass secure authentication paths
• Static or reused credentials may still be in use
• You risk audit failure and real security incidents
Replay resistance only protects your systems if it’s in place—and working.
How to Implement It
1. Validate Enforcement Across All Access Points
• Attempt logins to confirm that replay-resistant mechanisms (e.g., MFA, tokens, Kerberos) are in use
• Test external, remote, and privileged access scenarios
2. Review Logs and System Behavior
• Look for authentication events that prove replay resistance (e.g., time-based tokens, unique challenge-responses)
• Check for absence of static credential reuse or legacy authentication use
3. Interview Technical Staff or Demonstrate Live
• Be prepared to show that replay-resistant mechanisms are live during assessments
• Staff should be able to explain how authentication mechanisms work and where they apply
4. Cross-Check Configuration and Functionality
• Ensure that what’s configured matches how the system behaves
• Use test accounts or sandbox environments to simulate logins and observe enforcement
5. Include System-to-System and API Use Cases
• Confirm that programmatic access also uses replay-resistant methods (e.g., short-lived tokens, OAuth2)
Evidence the Assessor Will Look For
• Live demonstration or screen recordings showing replay-resistant login flows
• Logs of authentication events showing token-based or challenge-response mechanisms
• Screenshots of token expiration, MFA use, or time-based login restrictions
• Reports showing detection of failed replays or stale credential use
• Documentation confirming that replay-resistant controls are applied system-wide
Common Gaps
• Some systems or accounts bypass secure authentication mechanisms
• Legacy services still support basic or static authentication
• Configurations exist, but are not applied universally
• No live evidence to prove enforcement is working
How Cuick Trac Helps
Cuick Trac supports this requirement by:
• Ensuring replay-resistant authentication is enforced across the secure enclave
• Blocking static or legacy authentication methods by default
• Logging successful and failed access attempts using token-based or MFA-protected authentication
• Supporting live validation of secure authentication flows during audits
• Providing documentation, screenshots, and audit logs to prove implementation beyond policy
With Cuick Trac, your security controls are provable—not theoretical.
Final CTA
You can’t just say you’ve implemented secure authentication—you have to show it.
Schedule a Cuick Trac demo to verify that your authentication controls are active, enforced, and resilient against replay attacks.