In May, the company released a paper on its approach to cloud services and how the company plans to secure those services. The paper—penned by Microsoft's Global Foundation Services, the group responsible for overseeing the company's software-as-a-service infrastructure—spells out the current dangers for online services, including a growing interdependence between customers and the companies that serve them and more sophisticated attacks on Internet services.

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Microsoft argues that its approach to security, which it carved out with its Trustworthy Computing Initiative in 2002, works as well for online services, with some modification.

"If I take the traditional security principles, that hasn't changed in terms of discipline and approach," said Charlie McNerney, general manager for business and risk management at Microsoft's GFS. "What has expanded is the amount of controls we have applied."

In recent interviews, McNerney and other cloud providers shared their thoughts on Microsoft's approach to securing cloud services and the data centers that power such services.

1. Discuss risk with customers

"What are the defect scenarios and the responsibilities that parties have in that environment when it breaks," McNerney says. "That is the type of thing that large enterprise companies want to talk about the most."

But Microsoft has found that security is not just a worry for their biggest clients. Web sites and e-mail are central to the brand of any company and have to be protected, he says.

"I don't find anyone casual on trust," McNerney says. "The small guy operating on the Web with his commerce site is just as passionate about security as the big guys."

2. Pay attention to compliance

The company reduced 26 different types of audits to a list of 200 necessary controls and mapped those controls across its data-center environments and services, McNerney says. Standardization means that Microsoft does not have to give every customer, or its auditor, access to the company's data centers.

"Larger enterprise customers want to understand the controls, but how many companies can I let into a data center?" he says. "If you think about what that could be, there is no way that I could let all those customers into our facilities."

Instead, Microsoft has an agreed-upon compliance framework that allows auditors to order off a menu of tests and get the results.

"Each company is going to want to understand the tests and results," he says. "Therein lies the opportunity and challenge."

3. Better standards needed

"Amazon has a view; Yahoo has a view; Google has a view," McNerney says. "But all our approaches are still different. The next wave is that all of us will have to come together with a framework that we will have to use to make it super-productive on the Web."

For example, the companies need to agree on a way of handling universal IDs. The problems with federated identity on the Internet have not been solved in the standards, he says.

"Customers are going to expect that this (cloud services) is an interoperable environment for them," he says.

4. Privacy and security are not so different

The result, which is somewhat surprising, he says, is that as the company developed its tools for managing security and privacy, it did not differentiate a lot between the two ideals.

"Most people approach security in one way and privacy in another," he says. "Those come together in a much more blended way in the cloud."

5. Don't generalize on cloud security

The security considerations for every cloud service are different, Chaudhry argues. While serving up office applications, e-mail services, and access to databases may scale well, other services—such as Exchange servers&mdash:require a lot of customization and are harder to secure, he says.

"Companies need to look at specific areas and address them properly," Chaudhry says. "There is not a single thing that can be done across the whole cloud-computing spectrum."

Database-as-a-service, storage-as-a-service and vulnerability-assessment-as-a-service all have different security considerations, he says. And the coming Azure platform-as-a-service will as well.

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