Spectrum in the US is incredibly valuable to science, education, commerce, transportation, and contemporary life. Wireless bandwidth needs are rapidly growing, but allocation of spectrum to wireless users should not come at the expense of scientific observation in astronomy and earth science which are already under-allocated and subject to interference when operating opportunistically outside the narrow protected bands. This project is developing new secure and accountable sharing protocols that not only enable more efficient sharing of the spectrum between terrestrial commercial wireless systems and passive receivers, but also empowers passive systems to force a particular interfering transmitter to switch band. Improved coexistence allows more reliable operation of radio astronomy receivers. This project is creating open source software and data, and working with the ITU-R to ensure that results impact the research community and future spectrum sharing policy. Developments are impacting undergraduate and graduate education through course material and research experiences, and the project is engaged in K12 outreach.
This project is developing RF watermarks that embed random pseudonyms into transmitted wireless communication signals so that passive receivers can demodulate the pseudonym of any interferer. The proposed system then allows passive receivers to indirectly inform the interfering device to change band. To prevent any other device from inferring private information, the proposed system leverages differential privacy to quantitatively limit privacy leakage. Further, the project is adapting software attestation to develop proof of correct execution of spectrum decision on user equipment, and complementing the watermark-based detection system with spectrum policy enforcement. Protocols under study are being implemented and tested on PAWR testbeds as an open source project. Extensive experimentation, including at the Owens Valley Radio Observatory, is validating the technical contributions, and quantifying its performance and robustness to attacks.
Neal Patwari (neal.patwari@utah.edu) at The University of Utah
Ning Zhang (zhang.ning@wustl.edu) at Washington University in St. Louis
Greg Hellbourg (ghellbourg@astro.caltech.edu) at California Institute of Technology
Spectrogram-based interference source attribution at OVRO: An over-the-air validation using pseudonymetry [PDF]
M. G. Weldegebriel, Z. Li, G. Hellbourg, N. Zhang, N. Patwari
National Radio Dynamic Zones Workshop at the 2026 IEEE RFID Conference, 16 June 2026
Sensing and Stopping Interfering Secondary Users: Validation of an Efficient Spectrum Sharing System [PDF]
M. G. Weldegebriel, Z. Li, D. Maas, G. Hellbourg, N. Zhang, N. Patwari
IEEE International Symposium on Spectrum Innovation (DySPAN 2026), May 12-14, 2026, Washington DC
EMILY: Electro Magnetic Interference Ledger & registrY [PDF]
G. Hellbourg, N. Patwari, N. Zhang
2026 USNC-URSI National Radio Science Meeting (NRSM), 9 Jan. 2026
ConTest: Taming the Cyber-physical Input Space in Fuzz Testing with Control Theory [PDF]
J. Wang, H. Zhang, C. Jiang, A. Clark, N. Zhang
ACM Conference on Computer and Communications Security (CCS), 2025
Software Availability Protection in Cyber-Physical Systems [PDF]
A. Li, J. Wang, N. Zhang
USENIX Security Symposium, 2025
Tintin: A Unified Hardware Performance Profiling Infrastructure to Uncover and Manage Uncertainty [PDF]
A. Li, M. Sudvarg, Z. Li, S. Baruah, C. Gill, N. Zhang
USENIX Symposium on Operating Systems Design and Implementation (OSDI), 2025
Reactive interference management for radio astronomy in radio dynamic zones using ASTRA [PDF]
A. Sarbhai, D. Johnson, K. Webb, L. Stoller, O. Collaco, A. Orange, S. Zachary, B. Pearce, S. Tadik, S. Llosa, A. Aradhya, A. Pollak, W. Farah, J. Van der Merwe, K. Gifford, N. Patwari, G. Durgin, D. DeBoer, S. Kasera
2025 IEEE International Symposium on Dynamic Spectrum Access Networks (DySPAN), pp. 1-10, May 2025
Augmenting channel estimation via loss field: Site-trained Bayesian modeling and comparative analysis [PDF]
J. Wang, M. G. Weldegebriel, N. Patwari
Computer Networks, vol. 258, no. 110993, Feb. 2025
Watermarking of OFDM for pseudonymetry: Analysis and experimental results [PDF]
M. G. Weldegebriel, J. Wang, G. Hellbourg, N. Zhang, N. Patwari
2024 IEEE International Conference on Communications Workshops (ICC Workshops), pp. 317-322, June 2024
Please Tell Me More: Privacy Impact of Explainability through the Lens of Membership Inference Attack [PDF]
H. Liu, Y. Wu, Z. Yu, N. Zhang
IEEE Symposium on Security and Privacy (Oakland), 2024
Dynamic RFI management in radio astronomy using pseudonymetry [PDF]
G. Hellbourg, N. Patwari, M. G. Weldegebriel, N. Zhang
2024 United States National Committee of URSI National Radio Science Meeting (USNC-URSI NRSM), pp. 282-283, Jan. 2024
Spectrum management at the Owens Valley Radio Observatory
G. Hellbourg
URSIGASS, 2023
ARI: Attestation of Real-time Mission Execution Integrity [PDF]
J. Wang, Y. Wang, A. Li, Y. Xiao, R. Zhang, W. Lou, Y. Hou, N. Zhang
USENIX Security Symposium, 2023
IP Protection in TinyML [PDF]
J. Wang, Y. Wu, H. Liu, B. Yuan, R. Chamberlain, N. Zhang
Design Automation Conference, 2023
SlowLiDAR: Increasing the Latency of LiDAR-Based Detection Using Adversarial Examples [PDF]
H. Liu, Y. Wu, Z. Yu, Y. Vorobeychik, N. Zhang
IEEE / CVF Computer Vision and Pattern Recognition Conference, 2023
RIATIG: Reliable and Imperceptible Adversarial Text-to-Image Generation With Natural Prompts [PDF]
H. Liu, Y. Wu, S. Zhai, B. Yuan, N. Zhang
IEEE / CVF Computer Vision and Pattern Recognition Conference, 2023
Pseudonymetry: Watermarking Closed-loop SpectrumCoordination with Passive Receiver
M. G. Weldegebriel, J. Wang, N. Zhang, N. Patwari
IEEE Transactions on Cognitive Communications and Networking, 2023
PolyRhythm: Adaptive Tuning of a Multi-Channel Attack Template for Timing Interference [PDF]
A. Li, M. Sudvarg, H. Liu, Z. Yu, C. Gill, N. Zhang
IEEE Real-Time Systems Symposium (RTSS), 2022
Sensing and Stopping Interfering Secondary Users: Validation of an Efficient Spectrum Sharing System [Github Repo]
Tintin: A Unified Hardware Performance Profiling Infrastructure to Uncover and Manage Uncertainty [Tintin-Kernel] [Tintin-User]
Software Availability Protection in Cyber-Physical Systems [Github Repo]
Watermarking of OFDM for pseudonymetry: Analysis and experimental results [Github Repo]
ARI: Attestation of Real-time Mission Execution Integrity [Github Repo]
SlowLiDAR: Increasing the Latency of LiDAR-Based Detection Using Adversarial Examples [Github Repo]
RIATIG: Reliable and Imperceptible Adversarial Text-to-Image Generation With Natural Prompts [Github Repo]
IP Protection in TinyML [Github Repo]
This project is supported by NSF under award #2229427 and #2229428.