NIST SP 800-53 Rev. 5 IA-2(8) — Access To Accounts -- Replay Resistant

What this control requires

Implement replay-resistant authentication (e.g., nonces, time-synchronous authenticators) for privileged/non-privileged accounts to prevent replay attacks. This control supports the Authentication Solution capability within the Identification and Authentication family.

In plain English

Implement replay-resistant authentication (e.g., nonces, time-synchronous authenticators) for privileged/non-privileged accounts to prevent replay attacks. In practice, this means you can prove you access management-level controls on a defined cadence.

Why it matters

SP 800-53 is the catalogue every U.S. federal authorisation (FedRAMP, FISMA, CMMC) and most regulated industries point at. A missing control surfaces as a Plan of Action & Milestones (POA&M) item that an Authorizing Official must approve before the Authority To Operate is granted or renewed.

This control is rated high. Auditors expect a named owner, a remediation SLA, and a tooling artefact that evidences continuous operation.

What an auditor looks for

A 3PAO (FedRAMP) or Independent Assessor (NIST RMF) tests against NIST SP 800-53A assessment procedures. For each control they expect a documented implementation that addresses every assessment objective (Examine, Interview, Test) and an implementation summary in the System Security Plan.

Within Identification and Authentication, the assessor will trace your implementation back to the catalogue reference (Control IA-2(8)) and look for objective evidence on the latest two assessment cycles.

How to implement

1. Write a short policy stating intent, scope and named owner.
2. Encode it as a platform guardrail — SCP, Azure Policy initiative, Organisation Policy, or repository policy.
3. Wire a monitoring signal that catches drift (CSPM rule, SIEM rule, scheduled query, Workspace alert) and ticket it.
4. Review on a documented cadence and capture the review in the risk register or compliance tracker.

Operational checklist

• Access. Document the trigger, the owner and the cadence.
• Review. Document the trigger, the owner and the cadence.
• Authentication. Document the trigger, the owner and the cadence.
• Time. Document the trigger, the owner and the cadence.
• Identity. Document the trigger, the owner and the cadence.
• Scope: management, accounts, authentication, e, time, identity, review, capability.

Evidence to collect

• Identity Scan. IAM / IdP exports — Entra ID, Okta, IAM Identity Center, Workspace directory — showing accounts, roles, MFA state and last sign-in.

Identity analytics (Okta, SailPoint, Access Analyzer) demonstrates least-privilege. Focus: Access To Accounts -- Replay Resistant.

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.

• NIST SP 800-171 Rev. 3 3.5.4 — Replay-Resistant Authentication
• CIS Controls v8 14.9 — Conduct Role-Specific Security Awareness and Skills Training
• SOC 2 (2017 TSC) CC6.2 — Access Provisioning
• ISO/IEC 27001:2022 A.8.2 — Privileged access rights
• ISO/IEC 27701:2025 A.3.8 — Identity management

Related controls in NIST SP 800-53 Rev. 5

• Control IA-2(9) — Network Access To Non-Privileged Accounts -- Replay Resistant
• Control IA-2(3) — Local Access To Privileged Accounts
• Control IA-2(4) — Local Access To Non-Privileged Accounts
• Control IA-2(5) — Individual Authentication With Group Authentication
• Control IA-2(1) — Multi-Factor Authentication To Privileged Accounts
• Control IA-2(2) — Multi-Factor Authentication To Non-Privileged Accounts

References

• NIST Computer Security Resource Center — NIST SP 800-53 Rev. 5
• Catalogue identifier: Control IA-2(8)

Topics: identity accessprivileged accessidentity managementaccess review