NIST SP 800-53 Rev. 5 SC-40(1) — Electromagnetic Interference

What this control requires

Implement cryptographic mechanisms to protect against intentional electromagnetic interference (EMI) by ensuring that wireless spread spectrum waveforms used for anti-jamming are unpredictable to unauthorized individuals. These measures also reduce the effects of unintentional jamming from legitimate transmitters sharing the spectrum. This control supports the EMI Protection capability within the System and Communications Protection family.

In plain English

Implement cryptographic mechanisms to protect against intentional electromagnetic interference (EMI) by ensuring that wireless spread spectrum waveforms used for anti-jamming are unpredictable to unauthorized individuals. In practice, this means you can prove you review system-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 System and Communications Protection, the assessor will trace your implementation back to the catalogue reference (Control SC-40(1)) and look for objective evidence on the latest two assessment cycles.

How to implement

Secure Development

Pipeline. Require code review, SAST (Semgrep / Snyk Code), SCA (Dependabot / Renovate), secret-scanning and IaC scanning in the merge pipeline.

Branch protection. Protected branches enforce reviews, signed commits and passing CI before merge; document the protection rules as the control evidence.

Code Review Testing

Pipeline. Require at least one human reviewer plus passing CI (lint, type, unit, security scan) before merge — protected branches enforce this.

Operational checklist

• Review. Document the trigger, the owner and the cadence.
• Protection. Document the trigger, the owner and the cadence.
• Wireless. Document the trigger, the owner and the cadence.
• Cryptographic. Document the trigger, the owner and the cadence.
• Unauthorized. Document the trigger, the owner and the cadence.
• Scope: system, protection, review, capability, implement, code, secure, mechanisms.

Evidence to collect

• Code Repo Scan. Source-control evidence — branch protection, required reviewers, CI status, SCA / SAST reports.

Source control pipelines (GitHub, GitLab) enforce SDLC guardrails. Focus: Electromagnetic Interference.

Common pitfalls

• CI security checks set to warn-only; the merge button is faster than the security feedback.

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 3.14.2 — Malicious Code Protection
• BSI C5:2020 OPS-03 — Capacity Management - Controlling of Resources

Related controls in NIST SP 800-53 Rev. 5

• Control SA-14 — Criticality Analysis
• Control SI-8(3) — Continuous Learning Capability
• Control SA-12(13) — Critical Information System Components
• Control CP-10 — System Recovery And Reconstitution
• Control RA-4 — Risk Assessment Update
• Control SC-3(3) — Minimize Nonsecurity Functionality

References

• NIST Computer Security Resource Center — NIST SP 800-53 Rev. 5
• Catalogue identifier: Control SC-40(1)

Topics: governance risksecure developmentcode review testingdevsecops