Suppose we compare your data center to a water balloon. Both have a relatively secure perimeter. Both contain valuable content (water is the raison d'etre of a water balloon). Both face significant threats from pointed attacks. And in both cases, bad things happen when the perimeter is breached.

So why the comparison? Consider the following: How much do you spend to protect your data center applications from outside attacks? How about from attacks launched inside your network security perimeter? How secure is your valuable data against the misuse of privileged access accounts? When was the last time you changed all of your database passwords or all of your server passwords? Often, the answers to these questions reveal that a typical data center is about as secure as a water balloon.

In this article we burst the bubble of some common yet risky misperceptions about data center security. The goal is to get you thinking about threats that you may not have considered before. Then we describe some proven strategies you can adopt to resist these threats and improve the security of your valuable data.

Perimeter security is only a first step

If you're like many organizations, in the past decade you've focused your IT security efforts on strengthening the perimeter security of your data center. For instance, you may have installed an intrusion detection system (IDS). In our balloon analogy, this is like using thicker rubber: the barrier is stronger, but it remains the only defense against breaches.

A security strategy based on perimeter security assumes a lot of faith in the strength of the barrier. While it may be possible to resist known threats, the trouble is attackers eventually find new ways around barriers. And when they do, you'll want to have additional layers of defense in place to limit the scope and depth of the breach.

By itself, perimeter security is problematic for another reason: it's increasingly hard to define exactly where the perimeter is. As your company expands through organic growth or acquisitions, so too does the makeup and complexity of your network. Partners and customers gain ever more access to your online services, blurring the line between your network and theirs. New applications and technologies deployed beside your legacy systems create new administrative silos that may span historic network boundaries. How do you resolve the conflicting challenge of enabling easy access to and availability of your corporate data, while ensuring that the data is secure? It's tough to fill a balloon with water when the balloon itself is dissolving.