NIST SP 800-53 Rev. 5 CP-9(8) — Cryptographic Protection

What this control requires

Implement cryptographic mechanisms to prevent unauthorized disclosure/modification of backups, ensuring confidentiality and integrity per security category. This control supports the Encryption Software capability within the Contingency Planning family.

In plain English

Implement cryptographic mechanisms to prevent unauthorized disclosure/modification of backups, ensuring confidentiality and integrity per security category. 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 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 Contingency Planning, the assessor will trace your implementation back to the catalogue reference (Control CP-9(8)) and look for objective evidence on the latest two assessment cycles.

How to implement

Policy Management

Docs. Keep each policy in version-controlled Markdown alongside the code that implements it; ship a signed PDF snapshot at each annual review and link the SHA into the SoA.

Operational checklist

• Policy. Document the trigger, the owner and the cadence.
• Security. Document the trigger, the owner and the cadence.
• Data. 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.
• Scope: management, encryption, protection, software, capability, implement, policy, integrity.

Evidence to collect

• Policy Document. A signed and version-controlled policy / standard / procedure document.

Signed policy or standard documents the safeguard. Focus: Cryptographic Protection.

Common pitfalls

• Policies that no engineer has read; the version in Confluence drifts from the version that's actually being enforced.

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.

• HIPAA (45 CFR Part 164) 164.312(e)(2)(ii) — Transmission Security - Encryption
• SOC 2 (2017 TSC) P1.1 — Privacy Notice to Data Subjects
• BSI C5:2020 SP-01 — Documentation, communication and provision of policies and instructions

Related controls in NIST SP 800-53 Rev. 5

• Control SC-28(1) — Cryptographic Protection
• Control MP-8 — Media Downgrading
• Control SI-4(10) — Visibility Of Encrypted Communications
• Control CP-3(2) — Mechanisms Used In Training Environments
• Control CP-7(5) — Equivalent Information Security Safeguards
• Control CP-9(1) — Testing For Reliability And Integrity

References

• NIST Computer Security Resource Center — NIST SP 800-53 Rev. 5
• Catalogue identifier: Control CP-9(8)

Topics: data protectionpolicy management