What is Shared Responsibility Model?

Introduction to Cloud Security

When moving to the cloud, the responsibility for security shifts and evolves, but its importance only grows.

Cloud Security encompasses the policies, technologies, applications, and controls utilized to protect virtualized IP, data, applications, and infrastructure of cloud computing.

It's about ensuring confidentiality, integrity, and availability (CIA triad) of your assets in the cloud environment.

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The Shared Responsibility Model

Understanding this model is absolutely critical, as it clarifies who is accountable for what aspects of security in the cloud environment.

Definition:

• The Shared Responsibility Model is a framework that outlines the security obligations of the cloud service provider and the cloud customer.
• It specifies that the cloud provider is responsible for the security of the cloud (the underlying infrastructure), while the customer is responsible for security in the cloud (their data, applications, and configurations within the cloud environment).

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How It Works & Core Attributes:

• Security of the Cloud (Provider's Responsibility): The cloud provider is responsible for protecting the infrastructure that runs all of the services offered in the cloud. This includes the physical facilities, networking hardware, compute hardware, and the virtualization layer. They handle:
  • Physical security of data centers.
  • Network infrastructure (routers, switches, firewalls that manage traffic between customers).
  • Hardware and software that run the cloud services (e.g., hypervisors, underlying operating systems for PaaS).
  • Global network backbone that connects regions and Availability Zones.
• Security in the Cloud (Customer's Responsibility): The customer is responsible for the security of their data, applications, and configurations within the cloud environment. This responsibility shifts based on the cloud service model (IaaS, PaaS, SaaS). The customer handles:
  • For IaaS: Operating system configuration and patching, application code and configuration, network configuration within their VPC (e.g., Security Groups, NACLs), data encryption, and user access management.
  • For PaaS: Application code, application configuration, data management, and user access management. The provider manages the OS, runtime, and middleware.
  • For SaaS: User access management, data classification, and ensuring appropriate user configuration. The provider manages almost everything else.

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Analogy: A Hotel vs. Your Hotel Room This analogy is often used to simplify the Shared Responsibility Model:

Hotel Management (Cloud Provider):

• The hotel management is responsible for the security of the hotel.
• This includes the building's structural integrity, fire safety systems, external security cameras, elevators, and the cleanliness of common areas. They ensure the building is safe to stay in.

You, the Guest (Cloud Customer):

• You are responsible for the security in your hotel room. This means locking your room door, not leaving valuables lying around, choosing who you invite into your room, and ensuring your personal items are safe.

Shared Responsibility:

• The hotel provides a secure building, but you must secure your own room and belongings within that building. Both parties have a role to play.

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Common Applications/Implications:

• Clarity on Obligations: Helps organizations define internal security roles and responsibilities.
• Risk Management: Ensures both parties address their specific areas of risk, preventing gaps.
• Compliance: Aids in demonstrating compliance to auditors by clearly delineating security controls.
• Security Tooling: Guides customers in selecting and implementing the appropriate security tools and practices for their responsibilities (e.g., using IAM, configuring firewalls, encrypting data).
• Incident Response: Clarifies initial points of contact and responsibilities during a security incident.

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Quick Note: Your Active Role is Crucial

• While cloud providers invest billions in securing their infrastructure, remember that the Shared Responsibility Model places a significant and active role on the customer.
• Ignoring your security responsibilities in the cloud can lead to severe vulnerabilities, data breaches, and non-compliance, even if the cloud provider's infrastructure is perfectly secure.