What evidence do auditors commonly ask for on CRY-03 Encryption of sensitive data for storage?

Storage encryption design identifying where the customer holds the private key material; Signed terms covering key custody and any agreed departure from customer-only knowledge; Written exception procedure together with the log of exceptions actually invoked; Demonstration that provider personnel cannot retrieve keys held by the customer.

What is the most common gap auditors find on CRY-03?

Provider-managed keys presented as customer keys while the provider retains full retrieval ability

BSI C5 (121-criteria catalogue) · C5: Cryptography and Key Management

`CRY-03` Encryption of sensitive data for storage

Encrypt cloud customer data while it is stored and keep the private keys known only to the customer, handling any exception through a specified procedure that is contractually agreed with that customer.

Source: BSI C5 (121-criteria catalogue), CRY-03. 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 BSI C5 (121-criteria catalogue) in the compliance library.

The edition of the catalogue is not stamped here; check the edition your attestation is issued against.

artefacts

held by a system

at each review

hard

to go live

Document repository

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

none for this control

periodic reviewEvidence produced at each review

none for this control

governing documentDocuments that govern the control

Storage encryption design identifying where the customer holds the private key material · Document repository
Signed terms covering key custody and any agreed departure from customer-only knowledge · Document repository
Written exception procedure together with the log of exceptions actually invoked · Policy repository / GRC workspace
Demonstration that provider personnel cannot retrieve keys held by the customer · Document repository

First move

No system holds this evidence for you: it is people and documents. Reminders and routing to the owner still save time. Put the document under version control with an owner and review date, and log each review as a record with reviewer and date.

Common gaps auditors find

Provider-managed keys presented as customer keys while the provider retains full retrieval ability
Departures from customer key custody practised operationally without any agreed basis
Encryption switched on for primary storage but absent on replicas, snapshots and archives

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

CRY-02 Encryption of data for transmission (transport encryption) · CRY-04 Secure key management