NIST SP 800-53 Rev. 5 SC-17 — Public Key Infrastructure Certificates

What this control requires

Issue public key certificates under an organization-defined certificate policy or obtain them from an approved service provider. Ensure that only approved trust anchors are included in trust stores or certificate stores managed by the organization. Trust anchors, such as root certificates from a certificate authority (CA), serve as authoritative sources for trust in cryptographic systems. This control supports the Public Key Infrastructure (PKI) System capability within the System and Communications Protection family.

In plain English

Issue public key certificates under an organization-defined certificate policy or obtain them from an approved service provider. In practice, this means you can prove you policy 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 critical in the source catalogue. Treat gaps here as production incidents in the risk register, not housekeeping.

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 System and Communications Protection, the assessor will trace your implementation back to the catalogue reference (Control SC-17) 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

• Policy. Document the trigger, the owner and the cadence.
• Security. Document the trigger, the owner and the cadence.
• Protection. Document the trigger, the owner and the cadence.
• Cryptographic. Document the trigger, the owner and the cadence.
• Chain. Document the trigger, the owner and the cadence.
• Scope: management, organization, system, service, only, protection, sources, capability.

Evidence to collect

• Vendor Risk Management. vendor_risk_management evidence

Third-party risk management evidence (assessments, contracts, due diligence) shows supplier oversight. Focus: Public Key Infrastructure Certificates.

Related controls in NIST SP 800-53 Rev. 5

• Control SC-7(19) — Block Communication From Non-Organizationally Configured Hosts
• Control SA-9(3) — Establish And Maintain Trust Relationship With Providers
• Control SC-23(5) — Allowed Certificate Authorities
• Control SA-12 — Supply Chain Protection
• Control SC-29 — Heterogeneity
• Control SC-30(2) — Randomness

References

• NIST Computer Security Resource Center — NIST SP 800-53 Rev. 5
• Catalogue identifier: Control SC-17

Topics: vendor riskvendor managementcertificate managementsupply chain securitykey management