Category: Cloud Security & Providers

Cloud Service Provider

Also known as: CSP, Cloud Provider, Cloud Solution Provider

Simply put

A Cloud Service Provider (CSP) is a company that delivers computing services, such as servers, data storage, databases, networking, and applications, over the internet on an on-demand, scalable basis. Instead of owning and operating their own physical infrastructure, customers can use resources provided and maintained by the CSP. Readers should note that the acronym CSP can also refer to Microsoft's 'Cloud Solution Provider' partner program, which is a distinct concept.

Formal definition

A Cloud Service Provider (CSP) is a third-party company that provides on-demand, scalable cloud computing resources over the internet, commonly delivered through service models such as Infrastructure as a Service (IaaS), Platform as a Service (PaaS), and Software as a Service (SaaS). Offerings typically include computing power, data storage, databases, and networking. The scope of this definition is limited to the general commercial concept as described in the provided evidence; it does not address government-specific authorization requirements (for example, FedRAMP authorization or DoD provisional authorizations), which impose additional obligations that a reader must verify against current authoritative sources.

Why it matters

Cloud Service Providers have become foundational to how both commercial organizations and government agencies deliver information systems, because they allow customers to consume computing power, storage, databases, and networking on demand rather than building and maintaining their own physical infrastructure. For compliance officers, information system security managers, and authorizing officials, this shift matters because responsibility for security does not disappear when workloads move to a CSP, it is shared. Understanding which controls the CSP operates and which remain the customer's obligation is central to any credible risk determination.

A critical point for defense and public sector readers is that using a commercial CSP does not, by itself, satisfy government authorization requirements. The general commercial concept described here is distinct from the additional obligations that frameworks such as FedRAMP authorization or DoD provisional authorizations impose. Treating a CSP's general availability or its marketing of security features as equivalent to an Authority to Operate would be a serious error; authorization is a separate, time-bound determination that must be verified against current authoritative sources.

Readers should also be careful with terminology. The acronym CSP most commonly refers to a Cloud Service Provider, but it can also denote Microsoft's Cloud Solution Provider partner program, which is a distinct concept describing a reseller and partner authorization model rather than a general category of cloud infrastructure providers. Conflating the two can lead to confusion in contracts, assessments, and documentation, so practitioners should confirm which meaning is intended in any given context.

Who it's relevant to

Authorizing Officials and ISSMs

Those responsible for authorizing or securing information systems need to understand that adopting a CSP introduces a shared-responsibility arrangement, not a transfer of all security obligations. They should confirm which controls the provider operates versus which the customer must implement, and treat any government authorization decision as separate from the CSP's general commercial availability.

Compliance Officers and Auditors

Compliance and audit personnel must distinguish the general commercial concept of a CSP from government-specific authorization requirements such as FedRAMP or DoD provisional authorizations, which impose additional obligations. They should also confirm which meaning of the CSP acronym applies in a given document, since it may refer to a Cloud Service Provider or to Microsoft's Cloud Solution Provider partner program.

Government Contractors and Acquisition Personnel

Contractors selecting or reselling cloud services should verify that a provider's offering meets the specific authorization and contractual obligations applicable to their systems, rather than assuming that commercial cloud availability satisfies those requirements. Terminology and scope should be confirmed against current authoritative sources before commitments are made.

Inside CSP

Service Offering

The infrastructure, platform, or software services a CSP makes available to government and commercial customers, commonly categorized as IaaS, PaaS, or SaaS. The specific service model affects how security responsibilities are divided between the CSP and the customer agency.

Shared Responsibility Model

The delineation of which security and compliance controls the CSP implements versus those the customer organization must implement. The boundary shifts depending on the service model, and customers generally remain responsible for their data, access management, and configuration regardless of the provider's obligations.

Authorization Status

For federal use, a CSP's cloud service offering is typically assessed and authorized through the FedRAMP process, which is maintained by the FedRAMP Program Management Office. Authorization is tied to a specific impact level (such as Low, Moderate, or High as generally defined under FedRAMP) and is time-bound and subject to continuous monitoring rather than permanent.

Authorization Boundary

The defined scope of systems, components, and data flows covered by a given assessment or authorization. Services or configurations outside the documented boundary are generally not covered by the authorization and must be evaluated separately.

Continuous Monitoring Obligations

Ongoing activities a CSP performs and reports to maintain an authorization, which may include vulnerability scanning, incident reporting, and periodic assessment deliverables. These obligations reflect that authorization status depends on sustained compliance, not a one-time review.

Common questions

Answers to the questions practitioners most commonly ask about CSP.

Does a FedRAMP authorization from a CSP automatically satisfy DoD requirements for handling CUI?

No. A FedRAMP authorization and DoD authorization are distinct, and one does not automatically satisfy the other. FedRAMP, managed by the FedRAMP PMO, provides a standardized authorization approach primarily oriented toward federal civilian agency use of cloud services. DoD generally applies additional requirements, and its Cloud Computing Security Requirements Guide (SRG) establishes impact levels and conditions for DoD use of cloud offerings that may go beyond a baseline FedRAMP authorization. A CSP holding a FedRAMP authorization may still need to meet supplemental DoD provisions before its service is acceptable for DoD workloads or CUI. Readers should verify the specific impact level and applicable DoD guidance against current authoritative sources, because requirements and tailoring vary.

Is a Cloud Service Provider's authorization permanent once it is granted?

No. An authorization for a cloud service, like any Authority to Operate, is generally time-bound and subject to continuous monitoring rather than permanent. The authorizing official's decision reflects an accepted level of risk at a point in time, and the CSP is typically expected to provide ongoing monitoring artifacts, report changes, and remediate findings. An authorization can be revoked or require reauthorization if the risk posture changes. Treating a CSP authorization as a one-time, permanent status is a common mistake; readers should confirm continuous monitoring obligations and reauthorization timelines against the applicable program's current requirements.

How should an agency determine which cloud impact level applies to a workload hosted by a CSP?

The applicable impact level generally depends on the sensitivity of the information involved and the governing framework. For federal civilian systems, FISMA-related categorization under the FedRAMP model commonly aligns to low, moderate, and high baselines. For DoD systems, the Cloud Computing SRG defines impact levels that reflect information sensitivity, including provisions for CUI. Agencies should categorize the information and system, then map that categorization to the appropriate impact level under the framework that governs the workload. Because tailoring and agency-specific interpretations exist, the specific determination should be confirmed with the responsible authorizing official and current official guidance.

What is the difference between a CSP's assessment and its authorization?

Assessment and authorization are distinct steps that are often confused. An assessment is the evaluation of a CSP's implemented controls against an applicable control set, typically producing findings and supporting evidence. Authorization is the separate risk-based decision by an authorizing official to accept the residual risk and permit operation. A completed assessment does not by itself constitute authorization to operate. Readers should keep these roles separate and confirm which body performs the assessment and which official issues the authorization for their specific program.

How are security responsibilities typically divided between a customer agency and its CSP?

Responsibilities are generally divided under a shared responsibility model, though the exact allocation varies by service model and offering. In many implementations the CSP is responsible for controls associated with the underlying infrastructure and platform it manages, while the customer remains responsible for configuration, data handling, access management, and controls specific to its own use. The precise boundary is typically documented in a customer responsibility matrix or equivalent artifact. Because this division differs across providers and service models, agencies should review the provider-specific responsibility documentation and confirm which controls they must implement themselves.

Does using an authorized CSP mean an agency's compliance and security obligations are fully met?

No. Using an authorized CSP does not, on its own, make the customer's system compliant or secure. Compliance and security are not the same thing, and the customer generally retains responsibility for the portion of controls within its scope, for its own authorization decisions, and for continuous monitoring of its use of the service. An authorized CSP can be one component of a compliant system, but the customer must still address its own responsibilities and confirm them against the applicable framework and current authoritative guidance.

Common misconceptions

A FedRAMP authorization automatically satisfies DoD requirements for handling defense information.

FedRAMP authorization does not by itself satisfy DoD-specific requirements. DoD generally applies additional criteria, such as the DoD Cloud Computing Security Requirements Guide and impact-level considerations, and requirements for Controlled Unclassified Information may involve further contractual obligations. Readers should verify the applicable DoD guidance and contract terms against current authoritative sources.

Using an authorized CSP transfers all security and compliance responsibility to the provider.

Under the shared responsibility model, the customer organization generally retains responsibility for its data, user access, and configuration of the services it consumes. An authorization covers the provider's defined boundary and does not relieve the customer of its own control obligations.

A CSP authorization is a permanent credential once granted.

An authorization is time-bound and contingent on continuous monitoring and sustained compliance. Authorization status can lapse or be revoked, and it applies only to the assessed service offering, impact level, and authorization boundary as documented.

Best practices

Confirm the CSP's authorization status, impact level, and authorization boundary against current official sources rather than relying on marketing claims, and verify that the specific services you intend to use fall within the authorized boundary.

Map the shared responsibility model explicitly for your service model (IaaS, PaaS, or SaaS) so that customer-side controls for data, access management, and configuration are clearly assigned and documented.

Do not assume a FedRAMP authorization satisfies DoD or other agency-specific requirements; verify additional DoD guidance and contractual obligations, especially where Controlled Unclassified Information is involved.

Treat authorization as time-bound and review the CSP's continuous monitoring deliverables and reporting on an ongoing basis rather than at procurement only.

Document the boundary between authorized and unauthorized services and evaluate any out-of-boundary components separately before relying on them.

Distinguish assessment from authorization and compliance from security in your evaluation, confirming that authorization decisions and residual customer responsibilities are addressed in your own system documentation.