ISO/IEC 27017 FAQ Shared Responsibility

Build the allocation for one customer entity, provider entity, named service and tier, service model, region, current architecture, and provider chain. For each task, record the actor, action, input, handoff, evidence, exception route, and outcome. Clause 6.1.1 says the parties should agree their roles, state them in an agreement, and confirm that the customer can fulfil its allocation. CLD.6.3.1 adds that shared roles should be documented, communicated, and implemented by both sides.

Map identity, customer and provider administration, configuration, vulnerability handling, event logging, monitoring, backup, incident response, digital evidence, data and record protection, provider change, continuity, and exit where relevant. Use provider-owned, customer-owned, or shared only after naming the work. For a shared backup row, for example, state whether the provider supplies snapshots or another capability, who selects scope and retention, who initiates or automates backup, who protects access, who performs restoration, and who tests the result.

Use service-model examples as prompts, not fixed classifications. In IaaS, provider logging can be limited to infrastructure while the customer logs virtual machines and applications, and backup generally resides with the customer unless the provider offers it. In PaaS and SaaS, the provider can operate more layers, but the customer still owns its service decision, customer identities and available settings, customer procedures, and agreed handoffs.

Trace inherited duties through upstream providers. An organization can buy infrastructure as a customer while supplying its own application service as a provider. ISO/IEC 27017 says a provider using peer cloud services should maintain or exceed the information-security levels promised to its own customers and pass security objectives into the supply chain. An upstream dependency does not erase the direct provider's downstream commitment.

Keep the executed agreement and incorporated versions, service-specific responsibility matrix, provider documentation, customer procedures, configuration evidence, access and logging reviews, incident contacts, backup specifications and restore tests, change records, assurance material, and exit plan as applicable.

Test the highest-risk handoffs and at least one routine handoff. Trace a provider alert to customer receipt and response, a provider backup capability to the customer's restore test, or a provider change notice to customer impact assessment. Record the service, trigger, owners, expected data and timing, observed result, exception, follow-up owner, and due date.

ISO/IEC 27017 does not prescribe internal approval titles. As a practical model, the cloud service owner can approve the complete allocation, each customer control owner can accept the activities assigned to that team, and supplier management can maintain provider and upstream commitments.

Security should challenge gaps and inconsistent allocations. Include privacy, legal, resilience, or regulatory owners when their requirements apply, and send unresolved gaps to the authorized risk owner.

ISO/IEC 27017:2015 sets no universal review interval. Set one from risk and applicable requirements, then review when the service model, tier, provider chain, architecture, data location, agreement, provider capability, assurance scope, or customer operating model changes.

Also review after an incident or failed handoff exposes an incorrect assumption. Update the agreement, matrix, procedures, risk treatment, and evidence links together so they describe the same boundary.