What evidence do auditors commonly ask for on OPS-24 Separation of Datasets in the Cloud Infrastructure?

Tenant separation design describing the isolation mechanism at each layer; Risk analysis output that justified the chosen separation approach; Test results from a deliberate cross tenant access attempt; Isolation configuration of tenant identifiers, network and storage for a sampled customer.

What is the most common gap auditors find on OPS-24?

Isolation enforced in the application layer alone over a shared database with no row level control

BSI C5 (121-criteria catalogue) · C5: Operations

`OPS-24` Separation of Datasets in the Cloud Infrastructure

Separate cloud customer data stored and processed on shared virtual and physical resources strictly, following a documented approach derived from the risk analysis, so that the confidentiality and integrity of that data are preserved between tenants.

Source: BSI C5 (121-criteria catalogue), OPS-24. 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

easy

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

Risk analysis output that justified the chosen separation approach · Document repository
Isolation configuration of tenant identifiers, network and storage for a sampled customer · Cloud console / configuration management

periodic reviewEvidence produced at each review

Test results from a deliberate cross tenant access attempt · Source control / CI pipeline

governing documentDocuments that govern the control

Tenant separation design describing the isolation mechanism at each layer · Document repository

First move

Automate the pull from your Document repository. Version-controlled document with owner, approval and review date as metadata.

Common gaps auditors find

Isolation enforced in the application layer alone over a shared database with no row level control
Separation design not revisited after a shared caching or messaging component was introduced
Cross tenant access asserted in the design but never actually tested
Administrative tooling able to traverse tenants without restriction or logging

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

OPS-23 Managing Vulnerabilities, Malfunctions and Errors - System Hardening · PI-01 Documentation and safety of input and output interfaces