# NIST SP 800-53 Rev. 5 AU-9(3) — Cryptographic Protection - Source: https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/au-9-3-cryptographic-protection - Section: [Compliance](https://support.icompaas.com/compliance) › [NIST SP 800-53 Rev. 5 Controls](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5) › AU — Audit and Accountability - Last updated: 2026-06-05 - Publisher: iCompaas, Inc. (https://www.icompaas.com) **NIST SP 800-53 Rev. 5**·Control `AU-9(3)`·high·Component: **Audit and Accountability** ## What this control requires > Implements cryptographic mechanisms, like signed hash functions, to protect the integrity of audit information and tools from unauthorized changes. This control supports the Cryptographic Module capability within the Audit and Accountability family. > > — NIST SP 800-53 Rev. 5, Control AU-9(3) ### In plain English Implements cryptographic mechanisms, like signed hash functions, to protect the integrity of audit information and tools from unauthorized changes. 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 **Audit and Accountability**, the assessor will trace your implementation back to the catalogue reference (Control AU-9(3)) and look for objective evidence on the latest two assessment cycles. ## How to implement #### Logging Monitoring **AWS.** Org-trail CloudTrail to a central log archive account, GuardDuty in every region, and Security Hub for cross-source correlation. **Azure.** Pipe every diagnostic setting into a central Log Analytics workspace; onboard Microsoft Sentinel for SIEM/SOAR. **GCP.** Aggregate audit logs in a dedicated logging project with sink to BigQuery; enable Security Command Center Premium and route findings to Chronicle SIEM. #### 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. - **Audit.** Document the trigger, the owner and the cadence. - **Information.** 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, information, functions, audit information, protection, capability, accountability, tools. ## 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 - Per-account logging that nobody stitches together at the org level — incidents that cross accounts go undetected for days. - 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. - [**NIST SP 800-171 Rev. 3 3.3.8** — Protection of Audit Information](https://support.icompaas.com/compliance/nist-sp-800-171-rev-3/3-3-8-protection-of-audit-information) - [**ISO/IEC 27001:2022 A.8.34** — Protection of information systems during audit testing](https://support.icompaas.com/compliance/iso-27001-2022/a-8-34-protection-of-information-systems-during-audit-testing) - [**HIPAA (45 CFR Part 164) 164.312(e)(2)(i)** — Transmission Security - Integrity Controls](https://support.icompaas.com/compliance/hipaa/164-312-e-2-i-transmission-security-integrity-controls) ## Related controls in NIST SP 800-53 Rev. 5 - [**Control AU-16** — Cross-Organizational Audit Logging](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/au-16-cross-organizational-audit-logging) - [**Control AU-13(1)** — Use Of Automated Tools](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/au-13-1-use-of-automated-tools) - [**Control AU-16(3)** — Disassociability](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/au-16-3-disassociability) - [**Control AU-6(4)** — Central Review And Analysis](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/au-6-4-central-review-and-analysis) - [**Control SI-8(2)** — Automatic Updates](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/si-8-2-automatic-updates) - [**Control AU-3(3)** — Limit Personally Identifiable Information Elements](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/au-3-3-limit-personally-identifiable-information-elements) ## References - [NIST Computer Security Resource Center — NIST SP 800-53 Rev. 5](https://csrc.nist.gov/Projects/risk-management/sp800-53-controls) - Catalogue identifier: `Control AU-9(3)` Topics: governance risklogging monitoringpolicy management ## Related compliance guidance - [NIST SP 800-53 Rev. 5: a practical implementation guide for cloud teams](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5): Start with the full NIST SP 800-53 implementation guide — scope, roadmap, evidence and how the assessment runs. - [NIST SP 800-171 and CMMC: a practical guide to protecting CUI in the cloud](https://support.icompaas.com/compliance/nist-sp-800-171-rev-3): If your obligation is protecting CUI in your own systems for a federal or defence contract, this derived subset — not the full catalogue — is the requirement. - [SOC 2 compliance: a practical implementation guide for cloud-native SaaS teams](https://support.icompaas.com/compliance/soc-2-trust-services-criteria): Most commercial SaaS already hold a SOC 2 Type 2, and FedRAMP 20x Class A is designed for providers that have one.