Yaling Yang, an associate professor of electrical and computer engineering, is the lead investigator for two projects funded by the National Science Foundation (NSF). The first is a $750,000 collaborative research project that seeks to provide privacy and confidentiality in an environment where users share wireless spectrum. The second is a $200,000 project to improve communication for ocean vessels.

The first project, entitled "Collaborative research: Preserving user privacy in server-driven dynamic spectrum access," is a collaboration with the University of Buffalo. The research focuses on ways to protect user privacy when the Federal Communications Commission (FCC) makes the shift to sharing portions of the radio spectrum.

The booming demand for wireless service has led to a shortage of radio spectrum the band of radiation that enables telecommunication. There are too many users for the available spectrum. To solve the crisis, the FCC has proposed to open a cluster of its private radio bands, which were reserved for priority users like the military, to commercial users. While this will promote more efficient spectrum use, there are certain challenges for sharing bands between priority users and commercial users.

User interaction will be managed by something called a Spectrum Access System (SAS) database. The SAS requires devices to check in, report their location, request permission to transmit, and wait to be assigned a specific frequency.

Although sharing spectrum and taking turns sounds like a kindergarten lesson, SAS functions are complex, and privacy issues are paramount. Federal users often deal with classified information, and commercial data may hold trade secrets. The SAS database is not necessarily run by a trusted third party and could be breached by attackers.

The Virginia Tech-led project will develop a privacy-preserving SAS where both federal and commercial users need only share encrypted versions of their data with the SAS server. The server then performs homomorphic computation encrypted computations carried out on encrypted data to shield the data from any snooping party, including the SAS itself.

"Our design also ensures that the communication between users and the database is kept to a minimum," said Yang. "Users do not need to stay connected with the SAS system beyond the most basic handshakes."

Yang is also the lead investigator of a second NSF-funded project called "NeTS: Small long-range ocean communication links powered by energy harvesting," working with Virginia Tech associate professors Majid Manteghi, from electrical and computer engineering, and Lei Zuo, from mechanical engineering.

This project addresses the state of maritime communications, which lags far behind land-based innovation. Most existing marine communications technologies are limited and expensive. The Virginia Tech project looks to fill the void of broadband wireless communications at sea by developing self-powered ocean mesh networks. A collection of floating base stations, or nodes, "talk" to each other to create a network connection across a large area. Once they've been dropped in the water, the base stations start to harvest energy from ocean waves and automatically form a mesh network. Users can then connect to the Internet.

"The research of this project is the first that aims to provide broadband networking services to the vast majority of vessels and oil rigs at sea," said Yang. "It could have a significant impact on all aspects of maritime industry."

By improving the security and efficiency of communications for wireless users on land and at sea, Yang's research will provide faster, safer wireless connections farther abroad.