What evidence do auditors commonly ask for on 3.7.7 Prevent unauthorized substitution of keys?

Procedure for key loading with authorization and verification (for example key check values); HSM or KMS policy restricting key import to authorized roles and sources; Audit logs of key import or replacement events; Access matrix showing component holders cannot reach other components.

What is the most common gap auditors find on 3.7.7?

Any administrator can import a new key into the KMS without approval

PCI DSS v4.0.1 · Req 3: Protect Stored Account Data

`3.7.7` Prevent unauthorized substitution of keys

Key-management policies and procedures must be in place that stop cryptographic keys from being substituted without authorization. Guidance explains that an attacker who swaps in a key they know can decrypt everything encrypted with it, so encryption solutions should refuse any key that comes from an unexpected process or an unauthorized source, and individuals holding key components or shares should not also be able to reach enough other components to reach the threshold for deriving the key. Objective under the customized approach: unauthorized personnel cannot substitute cryptographic keys.

Source: PCI DSS v4.0.1, 3.7.7. 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 PCI DSS v4.0.1 in the compliance library.

Version 4.0.1 is the active version; 4.0 has been retired. Appendix A1 applies only to multi-tenant service providers, A2 only to card-present POS POI terminals that still use SSL or early TLS, and A3 only when a payment brand or acquirer requires it. Which requirements apply to you follows your validation type.

artefacts

held by a system

at each review

moderate

to go live

SIEM / log platform

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

Audit logs of key import or replacement events · SIEM / log platform

periodic reviewEvidence produced at each review

none for this control

governing documentDocuments that govern the control

Procedure for key loading with authorization and verification (for example key check values) · Policy repository / GRC workspace
HSM or KMS policy restricting key import to authorized roles and sources · Policy repository / GRC workspace
Access matrix showing component holders cannot reach other components · Policy repository / GRC workspace

First move

Start with the 1 of 4 artefacts that already live in a system (SIEM / log platform); keep the periodic reviews but log each one as a dated record with a named reviewer.

Common gaps auditors find

Any administrator can import a new key into the KMS without approval
Key check values not verified on load
No logging of key replacement events

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

3.7.6 Split knowledge and dual control for manual key operations · 3.7.8 Key custodians formally acknowledge responsibilities