Cloud Shared Responsibility Model: AWS vs Azure vs GCP
Learn how the cloud shared responsibility model splits security duties across AWS, Azure and Google Cloud, and what stays yours to own.
Cloud Shared Responsibility Model: AWS vs Azure vs GCP
The cloud shared responsibility model splits security duties between the cloud provider and the customer: the provider secures the underlying infrastructure, while the customer secures what they configure and put in the cloud. Every AWS, Azure, and Google Cloud outage or breach headline traces back to someone misunderstanding where that line sits.
If you are new to cloud security, this concept is the single most important thing to internalize before you touch IAM policies, encryption settings, or network rules. It is also one of the first topics tested on every major cloud security certification, and it shapes how a Cloud & AI Platform Security Engineer actually spends their day.
What the shared responsibility model actually means
Cloud providers describe their side of the split as "security of the cloud." That covers physical data centers, host hardware, the hypervisor, and the global network backbone. Customers own "security in the cloud," which includes their data, identity and access configuration, operating system patching (on unmanaged compute), network controls they define, and application-level security.
The exact dividing line moves depending on the service model:
- Infrastructure as a Service (IaaS), such as a virtual machine, gives the customer the most responsibility. You patch the guest OS, configure the firewall rules, and manage the application.
- Platform as a Service (PaaS), such as a managed database or serverless function platform, shifts more to the provider. They patch the runtime; you still own data, access policies, and application logic.
- Software as a Service (SaaS) puts the least burden on the customer, but identity, data classification, and user permissions are still the customer's job on every model.
According to AWS's official documentation, "AWS is responsible for protecting the infrastructure that runs all of the services offered in the AWS Cloud... Customer responsibility will be determined by the AWS Cloud services that a customer selects." Microsoft frames Azure's model the same way: infrastructure controls stay with Microsoft, while data, identities, and endpoints "never" fully transfer away from the customer, regardless of service tier.
AWS, Azure, and Google Cloud: how the split compares
The core idea is identical across the big three providers, but the terminology and emphasis differ slightly. Google Cloud has also introduced a complementary concept called "shared fate," where Google takes a more active role in helping customers reach secure default configurations rather than simply drawing a responsibility line and stepping back.
| Area | AWS | Azure | Google Cloud |
|---|---|---|---|
| Provider owns | Physical facilities, host hardware, hypervisor, network infrastructure | Physical facilities, host hardware, hypervisor, network infrastructure | Physical facilities, host hardware, hypervisor, network infrastructure |
| Customer always owns | Data classification, IAM policies, guest OS on EC2, network config | Data classification, identities, endpoint security, guest OS on IaaS VMs | Data classification, IAM policies, guest OS on Compute Engine VMs |
| Terminology | "Security of the cloud" vs. "security in the cloud" | Shared responsibility with a fixed customer core (data and identity) | Shared responsibility plus "shared fate," secure-by-default posture |
| Shifts most with | Service model (IaaS/PaaS/SaaS) | Service model (IaaS/PaaS/SaaS) | Service model, with more provider-led guardrails on managed services |
| Certification that tests this deeply | AWS Certified Security - Specialty | Microsoft Certified: Azure Security Engineer Associate (AZ-500) | Google Cloud Certified Professional Cloud Security Engineer |
Notice what stays constant no matter which column you look at: data protection, identity and access management, and configuration of anything you control are permanently the customer's job. Cloud providers will never take that responsibility away from you, which is exactly why IAM misconfiguration and exposed storage remain leading causes of cloud breaches.
Why security engineers need this model on day one
A Cloud & AI Platform Security Engineer uses this model constantly, often without naming it out loud, when they:
- Decide whether a finding belongs to the platform team or the provider's support queue.
- Scope a penetration test or audit to the systems the organization actually controls.
- Explain to a stakeholder why "the cloud provider handles security" is not a complete answer.
- Design IAM policies, encryption, and logging that cover the customer-owned half of every workload.
This is exactly the kind of foundational, hands-on judgment that PrimeSec Academy's curriculum is built around, with labs across AWS, Azure, GCP, and AI platform security rather than slides about theory alone.
Zero trust and the shared responsibility model work together
Shared responsibility tells you who owns what. Zero trust tells you how to defend the part you own. NIST Special Publication 800-207 defines zero trust as a set of concepts "designed to minimize uncertainty in enforcing accurate, least privilege per-request access decisions," shifting focus away from a trusted network perimeter and toward verifying every user, device, and request individually.
In practice, once you know a workload's guest OS, IAM policies, and data are yours to secure under the shared responsibility model, zero trust principles (least privilege, continuous verification, and micro-segmentation) become the toolkit you use to actually secure them.
Common mistakes teams make with this model
- Assuming "managed service" means "no responsibility." A managed database still needs correct IAM grants, encryption settings, and network access rules configured by the customer.
- Treating the model as a one-time training slide instead of an operational checklist. Every new service adopted by an organization needs its responsibility boundary mapped before go-live.
- Skipping identity. Across AWS, Azure, and Google Cloud, identity and access management is universally a customer responsibility and a leading root cause of incidents when it is misconfigured.
- Confusing compliance certification with security guarantee. A provider's compliance certifications (SOC 2, ISO 27001, and similar) cover their side of the model. They do not certify the customer's configuration.
How to build this into your career path
If you are studying for a cloud security role, pair the shared responsibility model with hands-on practice early. Reading about IAM least privilege is not the same as configuring it in a lab, breaking it, and fixing it under time pressure. Programs that combine the AWS, Azure, and GCP shared responsibility boundaries with real projects and a defended capstone tend to produce engineers who can explain and apply the model on day one of a new job, not just recite it in an interview.
If you are earlier in your research, PrimeSec Academy's certifications guide breaks down which cloud security credentials to pursue and in what order, and the career roadmap article walks through the broader path from beginner to hired.
Frequently asked questions
Is the shared responsibility model the same across AWS, Azure, and Google Cloud? The underlying principle is the same across all three: the provider secures the infrastructure, and the customer secures their data, identities, and configurations. The terminology and the specific service-by-service breakdown differ, and Google Cloud adds a complementary "shared fate" concept that emphasizes secure-by-default guardrails.
Does using a managed or serverless service remove my security responsibilities? No. Managed and serverless services shift infrastructure and patching duties to the provider, but you still own data classification, access policies, and how the service is configured and used.
Where does IAM fall in the shared responsibility model? Identity and access management is a customer responsibility on every major cloud platform and in every service model, from IaaS through SaaS. Misconfigured IAM is one of the most common root causes of cloud security incidents.
How does zero trust relate to the shared responsibility model? Shared responsibility defines who owns which parts of the environment. Zero trust, as defined in NIST SP 800-207, is a security approach you apply to the parts you own, based on least privilege and continuous verification rather than trusting a network perimeter.
Which certifications test knowledge of the shared responsibility model? It appears across cloud security certifications, including the AWS Certified Security - Specialty exam, Microsoft's AZ-500 (Azure Security Engineer Associate), and Google Cloud's Professional Cloud Security Engineer certification.
Do I need to memorize every line of the responsibility split for each provider? You need to understand the principle well enough to apply it to a new service you have never seen before: identify what the provider manages, what you must configure, and what stays permanently on your side (data, identity, and access).
Understanding the shared responsibility model is table stakes for any cloud security role, but applying it correctly under real conditions is what gets people hired. If you want structured, hands-on training across AWS, Azure, GCP, and AI platform security that builds this judgment through labs and a defended capstone, apply to PrimeSec Academy or explore the full curriculum to see how the program is structured.