Shared roles and responsibilities within a cloud computing environment

“Shared responsibility” in cloud is easy to say and hard to run. ISO/IEC 27017 CLD.6.3.1 narrows the problem to an operator-ready requirement: the security roles and responsibilities between the cloud service customer and cloud service provider must be defined, documented, and communicated. The practical risk is predictable: teams assume the CSP covers a control (logging, backups, key management, vulnerability remediation), a gap appears, and the organization can’t show who owned the obligation, when it was assigned, or how staff were informed.

For a Compliance Officer, CCO, or GRC lead, the fastest path is to treat this as a governance-and-evidence requirement. You need a shared responsibility matrix per cloud service (and per major service model: IaaS/PaaS/SaaS), a RACI that assigns internal accountability, and contract language that aligns the provider’s commitments to your control expectations. Then you operationalize it: embed ownership into workflows (tickets, change management, incident response), and keep artifacts that prove people actually followed the model.

Regulatory text

Requirement (excerpt): “Shared information security roles and responsibilities for the use of cloud services, including those of the cloud service provider and the cloud service customer, shall be defined, documented and communicated.” ¹

What the operator must do:

• Defined: Make explicit which party (CSP vs customer) performs each security activity and who is accountable for outcomes.
• Documented: Record the split in a durable format that is version-controlled and tied to the specific cloud service and deployment pattern.
• Communicated: Ensure relevant stakeholders can access it and demonstrate they were informed (and updates are pushed when responsibilities change).

Plain-English interpretation (what this really means)

You must eliminate ambiguity about “who does what” for cloud security. For every cloud service you rely on, you need a clear statement of:

• What the CSP commits to secure (and where their responsibility ends).
• What your organization must configure, operate, monitor, and prove.
• Which internal teams own those customer responsibilities (with accountable names/roles).

A generic CSP whitepaper is not enough by itself. You can reference provider documentation, but ISO/IEC 27017 expects your organization to define, document, and communicate your adopted responsibility split for your usage.

Who it applies to

Entity types:

• Cloud service customers: any organization consuming IaaS, PaaS, or SaaS and expected to manage security controls in that environment.
• Cloud service providers: organizations delivering cloud services that must clarify responsibilities to customers. ¹

Operational contexts where this becomes audit-critical:

• Multiple cloud models at once (SaaS for business apps, PaaS for data platforms, IaaS for workloads).
• Shared tooling (central IAM, SIEM, key management) spanning on-prem and cloud.
• Regulated data hosted in cloud (financial, health, sensitive personal data), where misaligned responsibilities create control failures.
• Mergers, cloud migrations, or rapid onboarding of third parties that access your cloud environment.

What you actually need to do (step-by-step)

1) Inventory your cloud services and your usage pattern

Build a list of cloud services in scope and capture the specifics that change responsibility boundaries:

• Service model: SaaS, PaaS, IaaS
• Tenant model: single tenant vs multi-tenant (if known/contracted)
• Data types stored/processed
• Critical integrations (SSO, logging pipelines, CI/CD, endpoint management)

Output: Cloud services register annotated with “responsibility complexity” notes.

2) Create a shared responsibility matrix per service (minimum viable version)

For each service, document responsibilities across a consistent set of control areas. A practical minimum set:

• Identity and access management (provisioning, MFA enforcement, privileged access)
• Logging and monitoring (what logs exist, who collects, who reviews, retention ownership)
• Vulnerability and patching (OS, platform components, app components)
• Configuration management (secure baselines, drift detection, change approvals)
• Encryption and key management (at rest/in transit, KMS ownership, key rotation)
• Backups and restore testing (who performs, RTO/RPO ownership if defined)
• Incident response (detection, notification timelines if contracted, forensics support)
• Data lifecycle (classification, retention, deletion, eDiscovery/legal hold)

Represent responsibilities with clear labels: CSP, Customer, Shared, and for “Shared” specify exactly which tasks belong to which party.

Output: Shared Responsibility Matrix (SRM) for each cloud service.

3) Convert the SRM into an internal RACI and assign accountable owners

ISO/IEC 27017 is not satisfied by “IT owns it.” Assign named roles/functions:

• Accountable: the internal role that answers to leadership/auditors (often system owner).
• Responsible: engineers/admins who run the control.
• Consulted/Informed: security, privacy, legal, procurement, business owner.

Tie each responsibility line-item to:

• A control ID in your control library (if you maintain one)
• A runbook/procedure
• A ticket queue or operational team

Output: Service-level RACI plus ownership mapping to operations.

4) Align contracts, SLAs, and third-party due diligence to the SRM

Your SRM must not contradict your agreement. Check:

• Security addendum and shared responsibility terms
• Breach/incident notification commitments (who notifies whom, how, and triggers)
• Audit report availability (SOC reports/assessments, scope, delivery cadence if provided)
• Subprocessors and data location/transfer commitments (if applicable)

Where the CSP is responsible for a control, confirm it is contractually supported or at least formally described in provider documentation you can retain.

Output: Contract crosswalk showing where each CSP responsibility is evidenced (contract clause, security exhibit, or provider attestation artifacts).

5) Communicate and embed the model into day-to-day workflows

Auditors will ask how you made this real. Practical methods:

• Publish SRM/RACI in your GRC repository or knowledge base with role-based access.
• Train: cloud engineering, service owners, security operations, procurement, and incident response.
• Embed into workflows:
  • Change management requires checking “SRM impact” for cloud changes.
  • Incident playbooks include CSP vs customer action steps and escalation paths.
  • New service onboarding checklist requires SRM completion before production use.

Output: Training records, onboarding gates, and workflow checklists referencing SRM.

6) Maintain it with change control

Cloud services change frequently. Add triggers to review and update SRMs:

• New cloud service onboarding
• Material architectural change (new region, new identity model, new logging pipeline)
• Contract renewal or provider policy change
• Major incident or postmortem finding tied to unclear ownership

Output: Version history, review approvals, and change log.

Required evidence and artifacts to retain

Keep evidence that covers all three verbs: defined, documented, communicated.

• Shared Responsibility Matrix per cloud service (version-controlled)
• Service-level RACI with accountable owners
• Cloud services register (inventory)
• Contract/SLA/security addendum crosswalk to SRM items
• Provider documentation package you rely on (saved copies or controlled references)
• Training/communication artifacts: attendance logs, LMS completion, email/announcement records, onboarding checklists
• Operational proof: samples of tickets/changes/incidents showing SRM-based routing (who owned what)
• Periodic review records: approvals, meeting minutes, or control owner attestations

Common exam/audit questions and hangups

Expect questions like:

• “Show me, for this SaaS, who is responsible for logging, review, and retention.”
• “Where is this responsibility documented, and who approved it?”
• “How did you communicate it to engineers and incident responders?”
• “What changed in the last year, and how did you update responsibilities?”
• “Prove that the CSP responsibility is supported by contract or formal documentation.”

Hangups that derail audits: SRM exists but has no owners; owners exist but can’t show they were informed; contract contradicts the SRM.

Frequent implementation mistakes (and how to avoid them)

1. Using a generic CSP shared responsibility diagram as your only artifact.
   Fix: produce your own service-specific SRM and reference CSP materials as inputs.

2. Treating “Shared” as a catch-all bucket.
   Fix: split “Shared” into task-level statements (e.g., CSP provides logs; customer collects and reviews them).

3. No linkage to contracts or procurement.
   Fix: add a contract crosswalk and require SRM review during renewals and onboarding.

4. No operational hooks.
   Fix: add SRM checkpoints to change management, incident response, and onboarding gates.

5. Shadow IT cloud services excluded.
   Fix: align SRM creation to your discovery process (finance spend, SSO catalog, CASB if you run one, procurement intake).

Enforcement context and risk implications

No public enforcement cases were provided in the source catalog for this requirement. Operationally, the risk is control failure from ambiguous ownership: missed patching boundaries, misconfigured storage, incomplete logging, gaps in incident escalation, and untested restores. Your exposure increases if you cannot show who owned the obligation and how the organization ensured the right teams knew their part.

Practical 30/60/90-day execution plan

First 30 days (stabilize and pick the path)

• Identify top-risk cloud services (by data sensitivity and business criticality).
• Build a standard SRM template and RACI template.
• Draft SRMs for the top services and assign accountable owners.
• Start contract crosswalk for those same services.

By 60 days (operationalize and prove communication)

• Publish SRMs in a controlled repository and roll out targeted training.
• Add SRM completion to cloud onboarding and procurement intake.
• Update incident response playbooks to include CSP/customer steps and contacts.
• Capture first evidence samples: changes and incidents routed according to RACI.

By 90 days (scale and harden)

• Expand SRM coverage across remaining cloud services and major platforms.
• Add review triggers to change management and renewal workflows.
• Run a tabletop incident to test the shared model and update gaps found.
• Prepare an audit-ready evidence bundle per critical cloud service.

Where Daydream fits

If you run third-party due diligence and cloud governance in parallel, Daydream can centralize the SRM, RACI, contract crosswalk, and review workflows so the “defined, documented, communicated” evidence is continuously audit-ready rather than rebuilt during assessments.

Frequently Asked Questions

Do I need a separate shared responsibility matrix for every cloud service?

You need service-specific documentation wherever responsibilities differ in practice. Start with a standard template, then tailor it per service and deployment pattern (SaaS vs PaaS vs IaaS, identity model, and logging architecture).

Can I rely on the CSP’s shared responsibility model document alone?

You can reference it, but ISO/IEC 27017 expects your organization to define, document, and communicate the responsibilities for your use of the service. Keep provider materials as supporting evidence, not the full control.

What does “communicated” mean in an audit?

Auditors look for proof that relevant teams received and can access the SRM/RACI, plus evidence it is used (training records, onboarding checklists, incident playbooks, and workflow prompts that reference the model).

Who should be accountable internally: Security or IT?

Assign accountability to the system or service owner role that can drive remediation and coordinate teams. Security often provides oversight and consultation, but accountability should sit with the function that runs the service day to day.

How do I handle “Shared” controls like logging or incident response?

Break “Shared” into discrete tasks with owners on each side. Example: provider generates logs and keeps platform integrity; you collect logs, set alerts, review, and retain them according to your policy.

What if procurement signed a contract that conflicts with our SRM expectations?

Treat it as a gap. Update the SRM to reflect reality, document the risk, and negotiate contract changes at renewal or add compensating controls on your side where feasible.

Footnotes

1. ISO/IEC 27017:2015 Information technology — Security techniques — Code of practice for information security controls based on ISO/IEC 27002 for cloud services