Cloud CIO: The Two Biggest Lies About Cloud Security

Treating the cloud security discussion as a black-and-white issue, where public clouds are insecure and private cloud are secure, is overly simplistic and leaves organizations that pursue either type of cloud environment vulnerable.

By Bernard Golden
Fri, May 27, 2011

CIO — Survey after survey note that security is the biggest concern potential users have with respect to public cloud computing. Here, for example, is a survey from April 2010, indicating that 45 percent of respondents felt the risks of cloud computing outweigh its benefits. CA and the Ponemon Institute conducted a survey and found similar concerns. But they also found that deployment had occurred despite these worries. And similar surveys and results continue to be published, indicating the mistrust about security persists.

Most of the concerns voiced about cloud computing relate to the public variant, of course. IT practitioners throughout the world consistently raise the same issues about using a public cloud service provider (CSP). For example, this week I am in Taiwan and yesterday gave an address to the Taiwan Cloud SIG. Over 250 people attended, and, predictably enough, the first question addressed to me was, "Is public cloud computing secure enough, and shouldn't I use a private cloud to avoid any security concerns?" People everywhere, it seems, feel that public CSPs are not to be trusted.

However, framing the cloud security discussion as a "public cloud insecure, private cloud secure" formula indicates an overly simplistic characterization. Put simply there are two big lies (or, more charitably, two fundamental misapprehensions) in this viewpoint, both rooted in the radical changes this new mode of computing forces on security products and practices.

Cloud Security Lie #1

The first big lie is that private cloud computing is, by definition, secure merely by way of the fact that it is deployed within the boundaries of a company's own data center. This misunderstanding arises from the fact that cloud computing contains two key differences from traditional computing: virtualization and dynamism.

The first difference is that cloud computing's technological foundation is based on the presence of a hypervisor, which has the effect of insulating computing (and the accompanying security threats) from one of the traditional tools of security: examining network traffic for inappropriate or malicious packets. Because virtual machines residing on the same server can communicate completely via traffic within the hypervisor, packets can be sent from one machine to another without ever hitting a physical network, which is where security appliances are typically installed to examine traffic.

Crucially, this means that if one virtual machine is compromised, it can send dangerous traffic to another without the typical organizational protective measures even being involved. In other words, one insecure application can communicate attacks to another without the organization's security measures ever having a chance to come into play. Just because an organization's apps reside inside a private cloud does not protect it against this security issue.

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