Security in terahertz WLANs with Leaky wave antennas

This paper presents the first security study of THz networks with Leaky Wave Antennas (LWAs). We employ a mix of analytical models and over-the-air experiments to explore the unique security properties of LWA links. We show via both models and experiments that the LWA's angle-frequency coupling leads to non-uniform secrecy capacity across sub-channels yielding advantages to an eavesdropper at edge frequencies. Yet, because different frequencies emit energy at 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.