| Scope and covered activity | ISO/IEC 27017 gives cloud-specific security control guidance for cloud service providers and cloud service customers. | ISO/IEC 27018 gives public-cloud PII processor privacy guidance for handling customer instructions, disclosure, deletion, and processor evidence. | Write the scope memo so teams can see when ISO/IEC 27017 is the implementation structure, when ISO/IEC 27018 controls the obligation or assurance question, and where evidence can be reused without changing the source test. Name the primary standard in the memo and file any overlap as a separate decision record. |
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| Who must act | ISO/IEC 27017 ownership should sit with the team that can operate the relevant management system, control process, risk method, supplier relationship, incident process, privacy process, or AI governance scope. | ISO/IEC 27018 ownership should follow that source's role model, such as regulator-facing accountable body, service organization, framework owner, provider, customer, processor, deployer, supplier, or risk owner. | Do not copy owners from one side to the other; map accountable owners, reviewers, and approvers separately. Put the owner name and team in the record before asking for evidence. |
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| Trigger or threshold | ISO/IEC 27017 work is triggered by scope definition, implementation, certification readiness, customer assurance, control gaps, incidents, supplier changes, or management review. | ISO/IEC 27018 work is triggered by its own legal, assurance, framework, contract, customer, or risk-management event. | Use the trigger to route intake: standards implementation, regulatory response, assurance report, framework mapping, customer request, or operational remediation. Log the trigger date and the routing owner so the queue is auditable. |
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| Core obligations | ISO/IEC 27017 requires practical governance: scope, roles, risk or impact decisions, evidence, operating cadence, monitoring, review, and improvement. | ISO/IEC 27018 requires public-cloud PII processor privacy guidance, so the record should show how PII handling expectations are identified and tracked separately from cloud-security controls. | Split the work into two task lists: one for cloud-security controls under ISO/IEC 27017 and one for public-cloud PII processor privacy under ISO/IEC 27018. Assign each task to one owner and one source before implementation starts. |
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| Evidence and records | ISO/IEC 27017 evidence should show the process operating: owners, decisions, registers, control records, test results, review minutes, audit samples, or corrective actions. | ISO/IEC 27018 evidence should match its own proof model, such as regulatory records, attestation evidence, framework profiles, risk analysis, or contractual assurance. | Build an evidence matrix with one row per claim and columns for source, owner, artifact, date, review trigger, and reuse permission. Capture the evidence owner in the matrix so no record is left orphaned. |
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| Timing and cadence | ISO/IEC 27017 timing follows implementation, audit, certification, review, supplier, incident, or change cycles rather than a single universal deadline. | ISO/IEC 27018 timing follows the legal effective date, assurance period, framework version, contract milestone, or publication lifecycle that applies to that side. | Track dates separately so an ISO review cycle does not get mistaken for a statutory deadline or assurance reporting period. Put the next review date in the register and set an alert owner. |
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| Enforcement or assurance route | ISO/IEC 27017 is usually tested through certification audits, internal audits, customer assurance, management review, or governance review, depending on how the organization adopts it. | ISO/IEC 27018 may be enforced, audited, attested, assessed, or used voluntarily depending on whether it is law, assurance criteria, a framework, or guidance. | Separate audit readiness from legal compliance and from voluntary framework maturity so executives see the actual consequence of gaps. Record which route applies and who owns closure. |
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| Overlap and reuse | ISO/IEC 27017 can supply reusable management-system evidence, control operation records, risk decisions, and review outputs. | ISO/IEC 27018 can reuse some of that evidence when the control, process, risk, or duty is genuinely the same. | Reuse evidence only after checking scope, actor, date, data type, service, supplier, and acceptance criteria; otherwise keep separate records. Mark each reused item so reviewers can trace why it qualified. |
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| Practical decision rule | Use ISO/IEC 27017 when the main work is building, operating, reviewing, or proving a management-system or standards-based control process. | Use ISO/IEC 27018 when the main work is satisfying that side's law, assurance route, framework outcome, risk method, or external reporting expectation. | If both apply, keep the primary obligation visible and use the other side as supporting structure, not as a substitute source. Record the chosen primary standard, the supporting standard, and the owner in the decision note. |
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