Brazilian Navy Officer’s Award-Winning NPS Research Advances 5G Network Security

Brazilian Navy Lt. Fernando De Oliveira has been awarded the Naval Postgraduate School’s (NPS) Outstanding Academic Achievement Award for International Student for his NPS thesis research, a patent-pending breakthrough in 5G network security that could provide operators with a scalable, mission-tuned approach for secure tactical communications.

“Lt. De Oliveira’s academic achievement is a testament to the high caliber of education NPS provides to our partners and allies as a coalition-building institution,” said Dr. Mowafiq W. Alanazi, deputy director of NPS’ International Graduate Programs. “What sets NPS apart from other educational institutions is its ability to combine advanced scientific instruction with real-world operational application—preparing graduates to tackle complex challenges and develop practical solutions.”

De Oliveira, who graduated from NPS’ computer science program with the 2026 Winter Quarter class in March of this year, says receiving the award came as a complete surprise.

“I was not expecting to get this award,” he noted. “I was just doing the best that I could during the whole time I was here — participating in the community, engaging with other students, and focusing on my research.”

And that research has proven to be anything but ordinary. The military doesn’t use 5G just for “faster internet.” Rather, it’s integrated as a foundational enabler of modern warfare, logistics and base operations, connecting sensors, troops, weapons and data systems, all in real time.

“Lt. De Oliveira has developed a new technical architecture for secure and granular user authentication in 5G Standalone (SA) and emerging 6G-oriented mobile networks,” said NPS computer science department chair Gurminder Singh. “This architecture has been successfully implemented in the NPS 5G test environment and has demonstrated potential applicability in defense communications, tactical networks, secure corporate environments, and multinational mission scenarios.”

Battlefield communications, command and control; the “Internet of Battlefield Things (IOBT)”; intelligence, surveillance and reconnaissance (ISR); autonomous systems and drones, logistics and “smart bases”; and electronic warfare and resilience are all increasingly reliant on 5G networks. However, a critical gap exists in modern telecommunications security, especially within defense applications.

While commercial 5G networks allow devices to connect seamlessly once authenticated, De Oliveira identified a key vulnerability: the lack of continuous, user-specific verification. In high-stakes environments such as military operations, simply trusting a device is not enough.

His thesis, titled “Slice-Aware User Authorization and Enforcement Manager for Fifth-Generation Networks: Testbed and Evaluation,” directly addresses this challenge.

“When you connect your phone to a 5G network today, you don’t need additional authentication beyond the device itself,” he explained. “But in a defense scenario, how do you know it’s really the authorized user? What happens if a device is lost or stolen?”

His solution introduces a second layer of security based on user identity, role and mission requirements. Built around the concept of network slicing, the system allows different users, such as commanders and frontline personnel, to access distinct segments of a network with tailored permissions and controls.

“For example, an admiral could access a command-and-control slice with higher privileges, while a soldier would access a different slice with more limited capabilities,” De Oliveira said. “Each user must authenticate, and their access is continuously verified.”

According to De Oliveira’s advisor, computer science professor Geoffrey Xie, the innovation lies not only in the concept but in how it is implemented.

“I’d say the most innovative aspect of Fernando’s system is that it allows enterprises to rapidly deploy customized security controls,” Xie said. “This is achieved by minimizing dependencies on standard 5G core functions.”

This flexibility makes the system particularly valuable in dynamic operational environments, where security requirements can vary significantly across mission sets and users.

The approach also aligns with the U.S. Department of War’s broader “zero trust” cybersecurity model, which assumes no user or device is inherently trustworthy and requires ongoing verification.

Turning theory into practice required significant technical innovation. Working in NPS’ Spanagel Hall, De Oliveira built a fully functional 5G testbed using a combination of open-source software and shared laboratory equipment.

The setup included a radio, antenna, computing system and mobile devices — all configured to simulate a private 5G network environment. After months of effort, he was able to successfully connect devices to the network.

“I spent about three months just getting the phone to connect to the 5G network in the lab,” he said. “That was the first challenge.”

Xie noted that the technical hurdles were substantial, particularly given the complexity of 5G systems and the limitations of available tools.

“The biggest challenge was the combination of the complexity of the 5G networking architecture and the limitations of available open-source codebases,” he said. “Fernando addressed this by leveraging existing functionality to the fullest extent and filling the remaining gaps with innovative code.”

After establishing the network, De Oliveira spent months developing the user authentication layer, implementing multiple verification methods including passwords, temporary codes and biometric-based authentication similar to modern passkey systems.

The system also allows administrators to enforce session time limits, automatically requiring users to reauthenticate after a specified period – further strengthening security.

In testing, the prototype demonstrated effective isolation between network slices, reliable enforcement of user permissions as well as the ability to control performance metrics such as bandwidth allocation.

“The testbed worked perfectly,” De Oliveira said. “We were able to prove the concept and show that this approach can enhance security in 5G systems.”

Beyond technical success, the research carries significant operational implications.

“Fernando’s innovation represents a major step forward in making 5G networks compatible with the security and agility requirements of U.S. military deployment,” Xie said. “His solution works across both public 5G infrastructures and privately operated 5G networks.”

De Oliveira’s work has already gained attention beyond the classroom. He presented his prototype at NPS’ Converge research event, and his advisor later showcased the research at the 2026 Department of the Navy Digital Warfighting Symposium West (WEST Conference) in San Diego.
The project has also entered the patent process, with initial approval granted by NPS – an indication of its novelty and potential impact.

“When the system worked for the first time, my professor said, ‘We should patent this,’” De Oliveira recalled. “We searched for similar work and couldn’t find anything close to what we developed.”

Several commercial companies have already expressed interest in De Oliveira’s work, he said, and in investing in equipment for 5G network research at NPS.

De Oliveira is quick to credit the support system around him for his success. Weekly meetings with his advisor helped him stay on target and maintain steady progress, while the broader NPS environment, which brings together students from around the world, sustained him.

“NPS was the place where I found myself as a researcher,” De Oliveira said. “I learned not only from American culture but from many different countries from my fellow students.”

As a father of two, he participated in school and community events, reinforcing the international connections NPS attendance is designed to celebrate. De Oliveira credits his family — his wife and children — with helping him navigate the challenges of an ambitious research project far from home.

“There were moments when I thought, ‘I won’t be able to do this,’” he said. “My wife told me ‘I believe in you’ and my children reminded me to stop working and spend time with family. Otherwise, I would have stayed in the lab all the time.”

Following his NPS graduation, De Oliveira has returned to Brazil to continue his naval career, but he has hopes of potentially returning to Monterey in the future. His NPS advisor team has recommended that he consider pursuing a Ph.D., continuing the important work in secure 5G communications that he started.

“I hope Fernando will be able to pursue a Ph.D. at NPS,” Xie said. “He has all the skill sets and motivation to be a top-notch researcher.”

Regardless of where he continues his work, De Oliveira plans to build on his research and maintain collaboration with NPS.

“I want to replicate this 5G lab [in Brazil] and continue developing the project,” he said. “I will stay connected with NPS and support other students working on related research.” In fact, multiple students have already begun building on his work at NPS, ensuring its continued impact.

De Oliveira’s success demonstrates the value of international collaboration in advancing both education and national security. His work not only contributes to emerging technologies but also strengthens ties between the United States and Brazil.

“I thank the Brazilian Navy and NPS for this collaboration,” he said. “This project is not finished — it’s just one stage. I want to continue this research and keep building on it.”

NPS, located in Monterey, California, provides warfighting-focused graduate education, including classified studies and interdisciplinary research, to advance the operational effectiveness, technological leadership, and warfighting advantage of the naval service. Established in 1909, NPS offers master’s, doctoral, and distance learning certificate programs to Department of War military and civilian students, along with international partners, to develop warfighters and leaders who can think critically, solve complex operational problems, and deliver mission-ready solutions through advanced education and research.