Shared Responsibility Model

The Shared Responsibility Model is a crucial concept that defines the security obligations of the cloud service provider and the cloud customer. It's a foundational element of cloud security that every user must understand to avoid dangerous gaps in their security posture. The model can be summarized as follows: the cloud provider is responsible for the security 'OF' the cloud, while the customer is responsible for security 'IN' the cloud. The provider's responsibility includes securing the physical infrastructure that runs all of the services offered by the cloud. This includes the hardware, software, networking, and facilities that run the cloud services, such as the physical data centers, host operating systems, and virtualization layer. The customer's responsibility depends on the service model they choose. In an IaaS model, the customer is responsible for a lot: securing the guest operating system (including patches and updates), managing the network configuration (firewalls, subnets), configuring identity and access management, and encrypting their data. In a PaaS model, the provider takes on more responsibility, managing the underlying OS, but the customer is still responsible for securing their application and managing user access. In a SaaS model, the provider manages almost everything, and the customer's main responsibility is managing their data and user access. Misunderstanding this division is a leading cause of data breaches in the cloud.