6 Deployment models
6.2 Private cloud

In a private cloud, the cloud infrastructure is a proprietary operated solely for a single client or organization. It is not shared with other organizations but it can comprise multiple consumers (e.g., business units). The infrastructure may be hosted internally or externally and it can be managed by the organization, by a third party or by some combination of them. It allows organizations to host data and applications in the cloud, in a more secure and controlled environment regarding public clouds. The resources are deployed behind a firewall and may be accessed across private leased lines or secure encrypted connections via public networks to get the specified clients (and only they) can operate. The objective of these mechanisms is to minimize security concerns and limit access to specific clients.

There are two variations of private clouds according to the place where it is hosted [10]:

On-Premise Private Cloud: This type of cloud is hosted within an organization’s own facility. This option is suitable for organizations that have invested in substantial server and storage hardware and want to leverage that investment and repurpose some of such equipment in a private cloud, either for applications that require complete control and configurability of the infrastructure and security.

Externally Hosted Private Cloud: Externally hosted private clouds are hosted by a third party specializing in cloud infrastructure. The service provider facilitates an exclusive cloud environment with full guarantee of privacy. This format is recommended for organizations that prefer not to use a public cloud infrastructure due to the risks associated with the sharing of physical resources.

Undertaking a private cloud project requires a significant level and degree of engagement to virtualize the business environment. Private clouds are more expensive but also more secure when compared to public clouds. An important part of IT decision-makers will focus exclusively on the private cloud, as these clouds offer the greatest level of security and control.

As a summary, a private cloud is the best option when