Published: Sept. 22, 2023 By

A team of University of Colorado Boulder researchers is leading a major military-oriented project for 5G wireless security.

The National Science Foundation’s Convergence Accelerator program has awarded CU Boulder $5 million for “GHOST: 5G Hidden Operations through Securing Traffic.” The goal of the work is to ensure American soldiers, businesses, and non-governmental organizations (NGOs) can use 5G cellular networks in foreign countries without untrusted or potentially hostile network operators being able to extract user information.

“This work is important for the United States because it inherently is about keeping our people safe,” said Eric Keller, a researcher on the project and an associate professor of electrical, computer, and energy engineering (ECEE).

While 5G signals are encrypted, preventing malicious operators from listening in on conversations, it is still possible to glean a wealth of data from transmissions. Accessible information includes the users on-line activities and physical location, as well as individual and organizational patterns of usage, according to Keith Gremban, principal investigator on the project and research professor in aerospace engineering sciences.

“We're addressing a problem most people haven’t even thought about,” said Gremban. “These larger issues with patterns of usage – what you’re doing on your phone, when, and where – reveals so much.”

The interdisciplinary team has developed systems to disguise cellular communications by anonymizing user data and locations, hiding pattern of usage information, and even generating intentional false flag communications to make observers believe groups of users are in one location when they are actually in another.

“We’re changing the way a phone or set of phones appears to a network operator,” Gremban said. “This is obviously important for soldiers but it’s so much more than that. A lot of companies and nonprofits operate in regions of the world that are less than stable. There have been a rash of kidnappings of corporate executives in some countries. They’re very interested in preventing people from tracking their cell phones.”

The team received a $750,000 Phase 1 grant last year for initial development of the technology. The new $5 million award is to combine the different components they have created into a single suite and commercialize the product.

“These tools will function as a set of software applications that run on your phone and are hidden so even if the phone is captured, people would have a tough time telling that there's anything unusual going on,” Gremban said.

Keller said the tools could make a big difference in hostile places.

“I've had the great fortune of being able to advise students at CU Boulder who were in the military, and hearing stories of situations they've been in really hits home the impact that GHOST could help keep them safer,” Keller said.

The GHOST Team in front of the Boulder Flatirons.
The GHOST Team in front of the Boulder Flatirons on campus.

A major business partner on the project is Federated Wireless, which builds and manages 5G networks. In addition to developing technology for user anonymization, Federated is helping test prototypes using real-world cellular equipment and is central to the team’s commercialization goals.

“Our work is focused on enhancing security of users of untrusted networks and streamlining private network provisioning,” said Kurt Schaubach, chief technology officer at Federated Wireless. “We are excited to work with university researchers to further enhance the security of private 5G networks for federal, defense, and commercial use."

Gremban said the team’s success in developing the initial technology demonstrates real promise for a forthcoming product.

“I’ve been working in wireless communications for a number of years, so I’m very concerned about wireless security,” Gremban said. “I’ve long had ideas in this area and being able to bring together an incredible team of people who also had ideas and then to turn our research into practice is very exciting.”

In addition to Gremban, Keller, and Schaubach, the team includes CU Boulder professors Alexandra Siegel of political science; Tamara Lehman of ECEE; and James Curry in applied math (APPM); as well as computer science (CS) research associate Stefan Tschimben; graduate students Zach Moolman of ECEE and Tyler Reiser of APPM/Data Science; and undergraduate student Isabella Bates of APPM/CS. Sal D’Itri, vice president of public sector at Federated Wireless, James Neel, senior technologist at Federated Wireless, and Joanna Crosby of RDM Pierce are also key contributors to the project.