Shaikhanov Paper to be Presented at IEEE Symposium on Security and Privacy

University of Maryland ECE Assistant Professor Zhambyl Shaikhanov, in collaboration with researchers from Los Alamos National Laboratory, Sandia National Laboratories, Rice University, and Brown University, has developed aproactive defensive technology that not only thwarts radar-based audio eavesdropping on smartphone conversations but also actively spoofs the eavesdropper with false audio information.

With millimeter-wave radars becoming ubiquitous, driven by 5G/6G and automotive sensing, attackers can purchase off-the-shelf radars and aim at unsuspecting victims to intercept sensitive audio conversations. By analyzing the subtle phase shifts in the reflected chirps, an adversary can detect tiny vibration patterns and reconstruct entire phone calls. Unfortunately, this analog micro-information cannot be encrypted or protected by existing methods, enabling attackers to bypass digital encryption and invade user privacy without installing malware or requiring physical proximity.

Shaikhanov and his team have pioneered a system that not only prevents attackers from decoding the true audio signal but also injects false signals to fool attackers into believing that they have succeeded. They developed an on-phone programmable metasurface and an audio-misinformation encoding technique that enables users to conceal private acoustic signals while simultaneously injecting an alternative signal to mislead attackers. In experiments involving audio conversations that included personal identifiers, bank account numbers, and Social Security numbers, the researchers demonstrated the capability; eavesdroppers recovered none of the original words and reconstructed only the injected misinformation.

“With the privacy of audio being of paramount importance, our technology transforms defensive measures from reactive to proactive and provides defenders with major strategic and security advantages. Such capabilities have applications across civilian, corporate, and military contexts,” said Zhambyl Shaikhanov.

The researchers’ paper describing the technology, titled “Spoofing Eavesdroppers with Audio Misinformation,” will be presented at the 46th IEEE Symposium on Security and Privacy on May 14, 2025. The IEEE Symposium on Security and Privacy is the premier forum for presenting developments in computer security and electronic privacy. It is sponsored by the IEEE Computer Society Technical Committee on Security and Privacy, in conjunction with theInternational Association for Cryptologic Research.

Published May 13, 2025