Cloud computing has raised the eyebrows of many enterprises today. If you have begun to delve beneath the surface of this new computing model, you have certainly discovered that there are many "clouds" to consider, and it is not one single cloud that will be part of your future. One of the hottest trends we are seeing right now among enterprises is the shift to private clouds. What is a private cloud, and how does it fit in your future?

The National Institute of Standards and Technology (NIST) offers a definition of clouds that is useful to consider. In their taxonomy, four different cloud deployments exist:

• Public Cloud: As the name implies, this type of cloud offering is generally available across the Internet and serves a virtually unlimited number of customers with the same infrastructure. Popular public cloud offerings, such as those from Amazon, Rackspace, Salesforce.com, Microsoft and Google, compete to provide a wide variety of IT services and business applications.
• Private Cloud: This type of cloud is purpose-built for a single organization, such as a financial institution or a government agency. Typically, the organization leverages technology for virtualizing operating systems and networks, and as a result may be able to collapse the number of servers and network devices - or at least manage them in a more coherent fashion.
• Community Cloud: This is a cloud that is built for a discrete and well-defined number of organizations. A supply chain or combination of several government agencies are good use cases to keep in mind when exploring this type of cloud.
• Hybrid Cloud: This defines a combination of a multiple of the above cloud deployments, which are integrated in some way to achieve communications in support of some business initiative. A user may need to access multiple clouds with a single set of credentials, data may need to flow between clouds, or a private cloud application may need to temporarily use public cloud resources (known as "cloud bursting").

When building a cloud computing strategy, many enterprises have been restricted to the comparison between public and private clouds. This is a fair starting point; large organizations have over time built relatively sophisticated IT architectures, systems and processes. This "internal" network provides context for considering a private cloud, while notions of outsourcing provide context for migrating systems into a public cloud. When comparing public and private clouds today, organizations should consider the following key factors:

• Cost: Which type of cloud is most cost-effective in the short-term and/or the long-term?
• Security: How does the security of a public cloud compare to what I can accomplish internally, and what are the risks to my organization?
• Compliance: Am I able to demonstrate compliance to regulatory mandates if I use a public cloud?
• Governance: What sort of visibility do I have into both the technology and the business practices of a public cloud provider, and do I have tools to manage the cloud provider?

Today, many organizations are making plans to both implement private clouds and utilize some services within public clouds. Organizational decision processes differ, however, as some may be using sophisticated risk-based decision support processes, while others may be driven solely by cost to determine which IT service is handled by which cloud deployment type. Private clouds are getting more attention now as they provide the means for gaining some benefits of cloud computing while maintaining a sense of control. In the long run, it is doubtful that organizations will be able to compete with the efficiencies of public cloud providers, and the short run of private clouds may in fact be very lengthy as organizations deal with very sensitive data and mission-critical systems.

Private and public clouds are no doubt a part of the future of your enterprise. Welcome to the world of hybrid clouds, and the key identity management standards that will enable it.