What evidence do auditors commonly ask for on AU-9(3) Protection of Audit Information | Cryptographic Protection?

Audit and accountability policy; System security plan; Privacy plan; Access control policy and procedures; Procedures addressing protection of audit information; System design documentation.

What is the most common gap auditors find on AU-9(3)?

No cryptographic mechanism such as hashing or signing protects the integrity of stored audit information

NIST SP 800-53 Rev 5 · AU - Audit and Accountability

`AU-9(3)` Protection of Audit Information | Cryptographic Protection

Implement cryptographic mechanisms to protect the integrity of audit information and audit tools.

Source: NIST SP 800-53 Rev 5, AU-9(3). The statement above is our statement of the clause, read from the published text and cited so you can check it against the official text, not the instrument verbatim. Open NIST SP 800-53 Rev 5 in the compliance library.

Base controls and their enhancements. Which apply follows the baseline you are assessed against (for example FedRAMP Moderate or High, or the low, moderate and high baselines of SP 800-53B). Text in square brackets is a parameter your organisation sets.

artefacts

held by a system

at each review

hard

to go live

Policy repository / GRC workspace

where the evidence lives

teal = a system already holds it · olive = produced at each review. To go live: easy when half or more of the artefacts are already held by a system, moderate from a quarter to a half, hard below a quarter.

These are the artefacts auditors commonly ask for on this requirement, our guidance rather than text from the standard. Your assessor decides what is sufficient in your context, and asks for samples across the period when a report covers one.

system holds itEvidence a system already holds

System hardware settings · Policy repository / GRC workspace

periodic reviewEvidence produced at each review

System audit records · Policy repository / GRC workspace
Test of Cryptographic mechanisms protecting the integrity of audit information and tools · Policy repository / GRC workspace

governing documentDocuments that govern the control

Audit and accountability policy · Policy repository / GRC workspace
System security plan · Policy repository / GRC workspace
Privacy plan · Policy repository / GRC workspace
Access control policy and procedures · Policy repository / GRC workspace
Procedures addressing protection of audit information · Policy repository / GRC workspace
System design documentation · Policy repository / GRC workspace
System configuration settings and associated documentation · Policy repository / GRC workspace

First move

Mostly documents and reviews. Pull the 1 system-held artefact from your Policy repository / GRC workspace on a schedule; put the documents under version control with an owner and review date, and log each review as a dated record with a named reviewer.

Common gaps auditors find

No cryptographic mechanism such as hashing or signing protects the integrity of stored audit information
Audit tools are not integrity protected by cryptographic means, so tampering with the tools would go undetected

Do this for your whole sheet

Paste the rows you run your controls from and get this mapping for every control at once, with the periodic-review ones flagged and a first move per row. No account for the first run.

Build my evidence sheet

AU-9(2) Protection of Audit Information | Store on Separate Physical Systems or Components · AU-9(4) Protection of Audit Information | Access by Subset of Privileged Users