A Brief History Lesson
Prior to World War II, Abraham Wald was a rising mathematician in Europe. Unable to obtain an academic research position in Austria due to his Jewish heritage, Wald eventually made his way to the U.S. to become one of the most important statisticians of the 20th century.
One of Wald’s most prominent works was produced for the U.S. government’s World War II-era Statistical Resource Group. The project examined aircraft that had returned from their combat missions and the locations of armor on the planes. Placement was, of course, no trivial matter. Misplaced armor would result in a negatively balanced, heavier and less maneuverable plane, not to mention a waste of precious wartime resources.
Tasked with the overall goal of minimizing Allied aircraft losses by placing additional armor in strategic locations on the plane, Wald challenged the natural instincts of military commanders. Conventional wisdom suggested that the planes’ survival rates might benefit from additional armor placed in the areas that suffered the highest volume of direct hits. But Wald found that was not the case.
Securing the Soft Spots
Leveraging data stemming from his examinations of planes returning from combat, Wald made a critical recommendation based on the observation of what was not actually visible: He claimed it was more important to place armor on the areas of the plane without combat damage (e.g., bullet holes) than to place armor on the damaged areas. Any combat damage on returning planes, Wald contended, represented areas of the plane that could withstand damage, since the plane had returned to base.
Wald reasoned that those planes that were actually hit in the undamaged areas he observed would not have been able to return. Hence, those undamaged areas constituted key areas to protect. A plane damaged in said areas would not have survived and thus would not have even been observed in the sample. Therefore, it would be logical to place armor around the cockpit and engines, areas observed as sustaining less damage than a bullet-riddled fuselage.
The complex statistical research involved in these and Wald’s related findings led to untold numbers of airplane crews being saved, not only in World War II, but in future conflicts as well.
Wald’s Strategy Applied to IT Security
What does this have to do with IT security? Let’s jump forward 70 years and apply Wald’s lessons to the IT security realm. Today, when it is not a question of if but when and where you will suffer a cyberattack, you must place your armor where it truly matters.
Basically, that means placing firewalls, network monitoring tools and other security products strategically around your PII, critical systems and your secret sauce. Do not lose sight of the big security picture just because you see thousands of scans of the external network a day or small individual cases of malware on noncritical systems.
Focus on Critical IT Assets
In the IT security realm, it is important to realize we cannot protect everything all the time. Attempting to secure everything would make network environments overly cumbersome and detrimental to business goals. We cannot afford to leverage protective technologies or resources with systems and data that are not critical since we live in a world of finite resources.
The lesson from Wald is simple: Identify what’s critical within your environment and place your armor where you need it — not in areas that, in the grand scheme of things, can sustain damage. In the present security landscape, it is essential to identify your critical IT assets and concentrate resources in those areas.
Today, it is almost a foregone conclusion that IT security incidents will occur. The key lesson from Wald is that the sheer volume of attacks must not obscure what is critical and should not influence you to concentrate resources inappropriately. What you actually see is not necessarily the true threat to your critical IT assets.