Cloud Security in a Shared Responsibility Model

Cloud security works best when duties are clearly shared. In cloud computing, the provider protects the underlying infrastructure—physical data centers, network hardware, and the core platform. You protect what you bring: your data, applications, and how users access them. The exact split depends on the service model you choose, from IaaS to SaaS. Understanding who is responsible helps you avoid gaps and misconfigurations.

Understanding the split of duties:

  • IaaS: The provider handles hardware, virtualization, and network services. You manage the guest operating system, your applications, data, and encryption keys.
  • PaaS: The provider takes care of runtime, middleware, and operating system updates. You still own data, application logic, access control, and securely configured applications.
  • SaaS: The provider runs the software stack end to end. You focus on user access, data governance, and high-level security controls.

Practical steps for teams:

  • Map each service to its responsibility and document the line.
  • Use strong identity and access management, with MFA and role-based access.
  • Protect data at rest and in transit; store keys in a dedicated key management service.
  • Harden configurations: baseline templates, least-privilege access, and automated checks.
  • Enable centralized logging and continuous monitoring; alert on unusual activity.
  • Practice vulnerability management: patch known flaws and retire unused services.
  • Prepare an incident response plan and run tabletop exercises regularly.
  • Maintain governance and peer reviews to stay compliant.

A simple cloud scenario: A three-tier web app runs in the cloud. The provider secures the network and the platform; you secure the database, encryption keys, and user access. When a new feature is released, you test it in a staging environment with the same security controls before going live.

Key takeaways

  • Responsibilities depend on the service model; document them to prevent gaps.
  • Strong IAM, encryption, and monitoring reduce risk and improve resilience.
  • Regular drills, audits, and governance help keep security aligned with business goals.

Key Takeaways

  • Responsibilities depend on the service model; document them to prevent gaps.
  • Strong IAM, encryption, and monitoring reduce risk and improve resilience.
  • Regular drills, audits, and governance help keep security aligned with business goals.