Date & Time: 

  2025 /11 / 21  (Fri) 14:20 - 16:20

 

Location: 

  Delta Building R216, NTHU

 

Speaker: 

  葉佳宜 教授

  國立臺灣大學 電機工程學系

 

Topic: 

   Security in High-Frequency Wireless Links

 

Abstract: 

   Millimeter-wave (mmWave) to terahertz (THz) bands spanning from 100 GHz to 1 THz are a key spectrum frontier for 6G networking. Highly directional “pencil beams” in such bands are often cited as inherently resilient to passive eavesdropping, despite a lack of empirical evidence. In this talk, I will share our work on high frequency link security considering its unique properties: high directivity and large bandwidth. First, we experimentally demonstrate practical eavesdropping threats of highly directional THz links despite the highly focused transmissions. Next, we examine the security challenges and opportunities of wideband mmWave and THz links due to the frequency-dependent radiation behavior. We show experimentally how joint coding across frequency channels enhances link secrecy when large bandwidth directional transmissions are subject to angular dispersion, in which different carrier frequencies emit towards different angles. Further, we propose to establish a stronger notion of security, which we term “absolute security,” by exploiting the spatial minima of the antenna pattern at different frequencies with secure coding.

 

Autobiography: 

    Chia-Yi Yeh is an Assistant Professor at the Graduate Institute of Communication Engineering at National Taiwan University. She received her Ph.D. and M.S. in Electrical and Computer Engineering from Rice University in 2022 and 2018 under the supervision of Prof. Edward W. Knightly, and her B.S. in Electrical Engineering from National Taiwan University in 2014. From 2022 to 2024, Chia-Yi Yeh was a Postdoctoral Associate affiliated jointly with the Department of Electrical Engineering and Computer Science (EECS) at Massachusetts Institute of Technology and the School of Engineering at Brown University, under Prof. Muriel Médard and Prof. Daniel M. Mittleman. Her research interests are design, implementation, and experimental demonstration of next-generation wireless systems for communication, security, and sensing based on theoretical foundations, for systems including massive MIMO, millimeter wave and terahertz networks.