Lesson 13

Shared Responsibility Model

Security 'of' the cloud vs. security 'in' the cloud — and how responsibilities shift by service type

The Shared Responsibility Model

Security and compliance are a shared responsibility between AWS and the customer. This model relieves the customer's operational burden while giving them the flexibility and control to deploy solutions on AWS. The distinction is commonly phrased as:

AWS is responsible for
Security of the Cloud
Customer is responsible for
Security in the Cloud

AWS Responsibility: Security of the Cloud

AWS operates, manages, and controls the components from the hypervisor virtualization layer down to the physical security of facilities where services operate. AWS protects the global infrastructure that runs all Cloud services.

Physical Infrastructure

  • Nondescript facilities with 24/7 security guards
  • Two-factor authentication for all physical access
  • Access logging and review, video surveillance
  • Disk degaussing and destruction for decommissioned storage

Hardware & Software Infrastructure

  • Servers, storage devices, networking appliances
  • Host operating systems, service applications, virtualization software
  • Routers, switches, load balancers, firewalls, cabling
  • Network monitoring at external boundaries, redundant infrastructure
  • Intrusion detection systems

AWS Global Infrastructure

Regions, Availability Zones, and edge locations are all AWS-managed. Third-party auditors verify AWS compliance with computer security standards and regulations — audit reports are available to customers.

Customer Responsibility: Security in the Cloud

Customers are responsible for security of everything they put in the cloud. The specific steps depend on the services used and the complexity of the system.

Customer-Managed Security

AreaCustomer Responsibilities
ComputeGuest OS patching and maintenance, application software, security group configuration
NetworkVPC configuration, subnet design, NACLs, firewall rules, intrusion detection/prevention systems
DataWhat content to store, which AWS services to use with it, which country it resides in, encryption (at rest and in transit), data format and masking
IAMUser/group/role management, permission policies, password policies, MFA, access key rotation
AccountLogin settings, root user protection, billing reports
Key principle: Customers maintain complete control over their content. They decide who has access, how access rights are granted/managed/revoked, and what security controls to implement.

Responsibility by Service Type

The level of customer responsibility shifts depending on how much the service abstracts away the underlying infrastructure.

TypeServicesCustomer ManagesAWS Manages
IaaSEC2, EBS, VPCGuest OS, applications, security groups, firewall configurationsPhysical, hypervisor, network up to the compute instance
PaaSLambda, RDS, Elastic BeanstalkCode or data, permissions, data classificationOS, database patching, firewall config, disaster recovery
SaaSTrusted Advisor, Shield, ChimeUsage configuration, subscription, data inputEntire infrastructure and application stack
Exam rule of thumb: The more "managed" the service, the more AWS handles. EC2 (IaaS) = customer handles OS patching. RDS (PaaS) = AWS handles database patching, customer handles data. Lambda (also PaaS) = AWS handles everything below the code.

Shared Responsibility Model Quiz

Select one answer per question. You will receive immediate feedback.

1. Under the AWS shared responsibility model, which party is responsible for patching the operating system on an Amazon EC2 instance?
2. Which of the following is solely the responsibility of AWS under the shared responsibility model?
3. A company deploys an application on Amazon RDS. Who is responsible for applying database engine patches?
4. Which security task below is the customer's responsibility, NOT AWS's, under the shared responsibility model?
5. Under the shared responsibility model, who is responsible for ensuring that data is encrypted in transit between EC2 instances?
Progress: 0/5 correct (0%). Answer all questions to see the final recommendation.
Primary Source: AWS Academy Module 4: AWS Cloud Security (module-4.txt) — Section 1: AWS Shared Responsibility Model.
Last updated: June, 2026© 2026 Shahriar Ahmed ShovonCredits