Who Protects The Internet?

Doomsday Scenario

Is there a guaranteed way to eliminate the threat? According to Barabasi, no. This is a property of scale-free networks, he says. "You can’t eliminate this vulnerability. There is no patch for it."

In the event of major hub failure, Barabasi believes the only option is damage control. He cites research by Adilson E. Motter, an assistant professor in the department of physics and astronomy at Northwestern University, showing that the selective removal of additional hubs immediately following a disaster can contain the damage around the stricken site. By shutting down the hubs most closely connected to the one under attack, you can prevent the failure from cascading through the entire network, Barabasi says. "If you shut down the hubs around an infected hub, the damage can be controlled."

Ultimately, the only real defense is to make Internet exchanges impregnable. Terremark’s newest facility is in Culpeper, Virginia, 60 miles southwest of Washington, D.C.—just outside the blast zone should a nuclear strike hit the capital. The facility is surrounded by a 10-foot-high earth berm, guards patrol the perimeter, and the staff includes Department of Defense–trained antiterrorism personnel.

"People have been worried about attacks on [hubs] since the Cold War," says Lewis of the CSIS. For instance, "since Eisenhower, the telecommunications network has been hardened against nuclear attack." What keeps SecureWorks’s Jackson awake at night is the prospect of a chemical, biological or dirty-bomb attack on a hub like Terremark. If no one can enter the building to staff the meet-point rooms, and everyone inside is already dead, it won’t be long before things start to fall apart. "There are so many different ways things could go wrong," he says. "Only one or two hardware faults can cause a cascade of failures that need constant manual intervention to resolve. You’d be lucky to limp along for two days until something catastrophic happens."

In Case of Code Red

Even something less than an all-out assault—a hybrid virtual and physical attack, for instance—might be enough to bring down an Internet exchange. If terrorists managed to gain remote access to a facility’s command-and-control system, they could, for example, cause the generators to overheat and explode. That would take out the cooling system and, soon enough, the meet-point rooms would be filled with the smell of burning motherboards.

If such attacks happened simultaneously at a sufficient number of hubs, the principles of scale-free networks dictate that the entire Internet could come down. Statistics on these types of assaults are hard to come by, but there were, for example, an average of 2,332 attempted virtual attacks each day on the supervisory control and data acquisition (SCADA) systems of SecureWorks’s utility clients last September, according to the firm. Only a small fraction of these attacks targeted actual command-and-control systems, but the sheer number of attempts is itself a cause for concern.

In fact, a successful command-and-control attack has already taken place in the U.S. In March 2007, the Department of Homeland Security staged an assault on a massive diesel generator of the kind used to run power plants and Internet exchanges. Hackers managed to gain control of the machine and cause it to self-destruct. Even a single exchange attacked in this way would take months to repair, according to John Bambenek, an information-security researcher who scans the Web for cyber-attacks as an incident handler with the Internet Storm Center, an early-warning network staffed by volunteers. "If two or three went out, you would run into manpower problems," he says. "There is not enough staff anywhere to do it. We are not as redundant as we think we are."

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