PCI Scope Reduction — Why not?

Bill Mathews, our Guest Blogger, is co-founder and CTO of Hurricane Labs (www.hurricanelabs.com), an information security services firm.

Limiting your PCI compliance scope can be beneficial in several ways. First it minimizes the amount of assets where PCI is applicable, but primarily it limits the number of places you can find credit card data on your network. The latter is the most important. PCI isn’t some huge, scary thing you should run away from and scope reduction won’t solve all your problems – but it can get you to a point where you understand what is really happening on your network. There are a few caveats and “gotchas” you will encounter along the way but the journey is worth it.

In order to reduce your PCI scope you must first classify your assets. This is much harder than it sounds for most organizations. You have to figure out what data goes where and how it flows. This mapping is crucial for proper scope reduction.  This type of awareness not only helps you with reducing your PCI scope but also helps you with general troubleshooting. Ultimately it will improve your process, It’s a win-win. If you don’t know where the data is then the bad guys will help you find it.

After you’ve happily mapped out your data flow and understand where things are and why; then you can move  to segmentation. Segmentation essentially allows you to split up your network into smaller chunks. This splitting up of your network makes implementing our next goal that much easier. Our next goal is implementing the principle of least privilege which essentially says, “if you don’t need access, you don’t get access.” I’ve often argued that proper implementation of least privilege will not only solve nearly all your compliance issues but goes a long way in solving all your security woes as well. Notice I said “proper implementation.” Many implementations of it are flawed. Following up this segmentation with a good access control test is very important, it’s one thing to have controls. It’s quite another to have them properly implemented.

By no means are these the only things you should do; but in my opinion they are crucial for reducing your risk. Accomplish these few things and you’ll be well on your way to both reducing your PCI scope and having a well-balanced security posture on your network. Overall it is worth the effort it takes.

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