One key to protecting networks: cut bandwidth requirements

A DOD official told Congress that reducing use of bandwidth could help shrink the attack surface for network-enabled systems.

The Defense Department, naturally, doesn’t like to go into detail about military plans, but it has lifted the veil a bit on what’s behind its Third Offset Strategy, in the name of transparency and deterrence. Knowing what you’re capable of can keep an adversary from attacking you.

DOD is pursuing five technical areas, including human-machine collaboration, learning systems and network-enabled, cyber-hardened autonomous weapons. One thing they have in common is high bandwidth requirements and, particularly with regard network-enabled weapons, some in Congress are concerned about DOD’s ability to protect them.

“You know we’re not really good at keeping adversaries out of our networks – let me rephrase that, we are good at it, at keeping them out, but they still get in,” Sen. Deb Fischer (R-Neb.) said at an April 12 subcommittee hearing. “So how are we going to have confidence that we have the ability to build this cyber-hardened network and do you think that the network should come before we think about the pieces that rely upon it? Should we make sure we have the security there before we get the bells and the whistles that depend upon it?” 

“I believe there’s a real opportunity here to co-design these capabilities in ways we have not in the past,” Assistant Secretary of Defense for Research and Engineering Stephen Welby responded.  Welby then expanded on the concept of autonomous systems and the man-unmanned teaming concept, noting how reducing bandwidth can shrink the attack surface of systems making them safer from intrusions. 

“We’re talking about manned-unmanned teaming and trying to understand how that works, what kind of bandwidth is required, where and when systems need to interact, I think is very important in scoping the networks required to support those,” he said. “We did some recent studies where we looked at just how little bandwidth was required to ensure control over, in a simulated environment, or some notional unmanned-manned system concepts, and we were very enthusiastic about the ability to shrink that amount of bandwidth required in very interesting ways. The smaller the pipe, the easier it is to protect. And so we’re thinking about very novel ideas in that space.”

Welby’s response prompted Fischer to ask if DOD needs all the precious spectrum it has. “Today I think we need all we have and more. We need it all,” Welby said.

While Welby noted that large bandwidth sensors are really challenged in the spectrum space and auctioning spectrum has caused DOD to shift in complex ways, he is excited about agile spectral use. “I am enormously excited about the initiatives that [the Defense Advanced Research Projects Agency] has started here in the last two weeks to set up prizes associated with very novel use of the spectrum…to think about new ways that we can architect our commercial and military systems to be really efficient users locally, regionally and globally to make the most use of the spectrum we have,” he said. 

Welby was referring to DARPA’s Spectrum Collaboration Challenge, which aims to imbue radios with advanced machine-learning capabilities to collectively develop strategies for optimizing use of the wireless spectrum that aren’t possible today due to the intrinsically inefficient approach of pre-allocating exclusive access to designated frequencies. 

Despite the efforts of DARPA and others, Welby warned, “The demand for spectrum is only going in one direction – wide-bandwidth applications on the commercial side, wide-bandwidth applications on the military side are going to grow. But in the fight…we’re going to want to be able to, if we lose that spectrum, to still be able to fight through. And we think there’s very interesting ways we can do that.”   

This notion has been seconded by DOD CIO Terry Halvorsen. “[T]here is a physical limitation to how fast we can move the DOD systems either into the ability to share spectrum or out of some spectrum,” he told Congress in March. “And I worry maybe because we’re victims of our own success – we’ve done very well and the legislation that’s been written and the sharing has all worked to date – but what I hear from industry right now is, ‘Well, we want to go faster.’ And I don’t know that we can go much faster today on how we look at spectrum, make the decisions of whether we can get out and how we would share.”

Halvorsen also worried aloud that national systems could be at risk as the private demand for spectrum could exceed ability to keep pace.