How Companies Can Protect Against Leakers

How Companies Can Protect Against Leakers
By Bruce Schneier
Aug 21 2013

Ever since Edward Snowden walked out of a National Security Agency facility in May with electronic copies of thousands of classified documents, the finger-pointing has concentrated on government’s security failures. Yet the debacle illustrates the challenge with trusting people in any organization.

The problem is easy to describe. Organizations require trusted people, but they don’t necessarily know whether those people are trustworthy. These individuals are essential, and can also betray organizations.

So how does an organization protect itself?
Securing trusted people requires three basic mechanisms (as I describe in my book “Beyond Fear”). The first is compartmentalization. Trust doesn’t have to be all or nothing; it makes sense to give relevant workers only the access, capabilities and information they need to accomplish their assigned tasks. In the military, even if they have the requisite clearance, people are only told what they “need to know.” The same policy occurs naturally in companies.

This isn’t simply a matter of always granting more senior employees a higher degree of trust. For example, only authorized armored-car delivery people can unlock automated teller machines and put money inside; even the bank president can’t do so. Think of an employee as operating within a sphere of trust — a set of assets and functions he or she has access to. Organizations act in their best interest by making that sphere as small as possible.

Limiting Damage
The idea is that if someone turns out to be untrustworthy, he or she can only do so much damage. This is where the NSA failed with Snowden. As a system administrator, he needed access to many of the agency’s computer systems — and he needed access to everything on those machines. This allowed him to make copies of documents he didn’t need to see.

The second mechanism for securing trust is defense in depth: Make sure a single person can’t compromise an entire system. NSA Director General Keith Alexander has said he is doing this inside the agency by instituting what is called two-person control: There will always be two people performing system-administration tasks on highly classified computers.

Defense in depth reduces the ability of a single person to betray the organization. If this system had been in place and Snowden’s superior had been notified every time he downloaded a file, Snowden would have been caught well before his flight to Hong Kong.


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