Security and Angle-Frequency Coupling in Terahertz WLANs

TY - JOUR

T1 - Security and Angle-Frequency Coupling in Terahertz WLANs

AU - Yeh, Chia Yi

AU - Ghasempour, Yasaman

AU - Amarasinghe, Yasith

AU - Mittleman, Daniel M.

AU - Knightly, Edward W.

N1 - Publisher Copyright: © 1993-2012 IEEE.

PY - 2024/4

Y1 - 2024/4

N2 - This paper presents the first security study of THz networks employing antennas with the angle-frequency coupling property. Using Leaky Wave Antennas (LWAs) as a representative, we explore the unique security properties due to the frequency-dependent radiation. We show via both analytical models and over-the-air experiments that LWA links exhibit non-uniform secrecy capacity across sub-channels, yielding advantages to an eavesdropper at edge frequencies. Yet, because different frequencies emit towards different angles, the eavesdropper is thwarted from easily intercepting an entire wideband transmission. The experiments diverge from the analytical model in that the model underpredicts the eavesdropper's advantage at angles smaller than the target user and subsequent asymmetric performance across angles. Nonetheless, both the model and measurements show that increasingly wide bandwidth and correspondingly wide beams have only a modest marginal security penalty. Further, we find the LWA link secrecy not only depends on the target user angle (due to nonlinearity of LWA's frequency-angle coupling), but also the beamwidth of the frequency components that constitute the collective LWA transmission.

AB - This paper presents the first security study of THz networks employing antennas with the angle-frequency coupling property. Using Leaky Wave Antennas (LWAs) as a representative, we explore the unique security properties due to the frequency-dependent radiation. We show via both analytical models and over-the-air experiments that LWA links exhibit non-uniform secrecy capacity across sub-channels, yielding advantages to an eavesdropper at edge frequencies. Yet, because different frequencies emit towards different angles, the eavesdropper is thwarted from easily intercepting an entire wideband transmission. The experiments diverge from the analytical model in that the model underpredicts the eavesdropper's advantage at angles smaller than the target user and subsequent asymmetric performance across angles. Nonetheless, both the model and measurements show that increasingly wide bandwidth and correspondingly wide beams have only a modest marginal security penalty. Further, we find the LWA link secrecy not only depends on the target user angle (due to nonlinearity of LWA's frequency-angle coupling), but also the beamwidth of the frequency components that constitute the collective LWA transmission.

KW - angular dispersion

KW - leaky wave antenna

KW - physical layer security

KW - Terahertz

U2 - 10.1109/TNET.2023.3321641

DO - 10.1109/TNET.2023.3321641

M3 - Journal article

AN - SCOPUS:85174849354

SN - 1063-6692

VL - 32

SP - 1524

EP - 1539

JO - IEEE/ACM Transactions on Networking

JF - IEEE/ACM Transactions on Networking

IS - 2

ER -