Amazon.com is tailoring its cloud computing services to make them more attractive to large enterprise customers. The company this morning launched a Virtual Private Cloud service, giving companies a way to migrate their IT infrastructure onto Amazon's cloud while keeping their security systems in place.

With the new private cloud offering, Amazon customers can connect to a "set of isolated AWS compute resources" through a Virtual Private Network (VPN) and continue to use their existing security tools, firewalls and intrusion detection systems in the Amazon cloud. Customers like Intuit and Eli Lilly are already using the private cloud, Amazon said.

"This enables enterprises to connect their existing infrastructure, which in many cases is billions of dollars, to a set of virtually isolated AWS resources," said Adam Selipsky, Amazon Web Services vice president of product management and developer relations, in an interview with TechFlash. "In other words, companies can create and cordon off isolated resources within the AWS cloud."

Amazon Web Services have made headway with startups and some enterprise customers who have used it for individual projects. But for the business to really take off, Amazon needs to score bigger customers and contracts, and overcome general concerns about the security and reliability of cloud computing.

Sunny Gupta, CEO of Bellevue-based Apptio, said Amazon's new private cloud service "will encourage deeper adoption of Amazon offerings."

"Customers can now migrate mission critical applications into Amazon cloud without worrying about their ability to access secure data and applications that reside within their own private networks," Gupta said. Apptio's online software system helps CIOs assess their IT costs and compare them to those of Amazon's cloud services.

Selipsky said adoption of Amazon Web Services and cloud computing generally is going to "unfold in pieces over a period of years." He added: "The single biggest barrier to enterprise adoption that exists today is the reluctance to live with one foot in each of two worlds, the on-premise IT infrastructure and the world of the cloud. What Amazon Virtual Private Cloud aims to do is bridge those two worlds."

The Amazon Virtual Private Cloud is now limited to the EC2 cloud compute service, though Amazon said it will include other web services in the future.

Amazon also this morning announced Multi-Factor Authentication, an extra security layer for its web services. With the new feature, "users must provide a six-digit, rotating code from a device in their physical possession in addition to their standard AWS account credentials, before they are allowed to make changes to their AWS account settings."

Update: Amazon CTO Werner Vogels in a blog post talks about the challenges Amazon has faced moving big companies and their IT systems to the cloud and writes that the new Amazon Virtual Private Cloud can address that problem:

One important piece of feedback that mainly came from our enterprise customers was that the transition to the cloud of more complex enterprise environments was challenging. We made it a priority to address this and have worked hard in the past year to find new ways to help our customers transition applications and services to the cloud, while protecting their investments in their existing IT infrastructure.

More technical details on the Amazon Web Services blog, including this diagram of how it works:

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