Public cloud

What does public cloud mean?

A public cloud offers cloud services to a broad customer base. Different companies can use the same provider’s offerings. NIST classifies public cloud as a deployment model; IaaS, PaaS and SaaS describe the type of service. Offering a service to the public does not require your stored data to be publicly readable.

Microsoft describes the responsibility customers retain for data, identities and access management. The other operational layers your team handles depend on the service and its configuration. The provider’s name alone does not answer that question.

A portal with protected documents

In the fictional customer portal P-32, the application runs in a public cloud. Project document D-17 should be accessible only to authorised members of the relevant project. Project membership is checked on the request; simply knowing the document address must not grant access. This is a requirement of our example, not a guaranteed feature of every cloud offering.

Before use, test authorised access, access without signing in and access from a different project. Also establish storage location, data export, backup and responsibility for changes. Public cloud specifies neither a particular region nor a fixed price or automatically lower total costs.

Sources

• NIST — The NIST Definition of Cloud Computing (SP 800-145)

• Microsoft — Shared responsibility in the cloud