Investigation of Eavesdropping Opportunities in a Meeting Room Scenario for THz Communications

Due to the large available bandwidth, wireless communications in the THz range are foreseen to provide high data-rate transmissions. Compared to transmissions at lower frequency ranges, wireless communications in the THz range are inherently more robust against eavesdropping attacks due to their propagation characteristics such as a high free space path loss. It does not connote, however, that eavesdropping is not possible. In this paper, ray-optical methods and confirming channel sounder measurements at 300 GHz are used to show that even common, ordinary features such as door frames or a TV screen in the selected meeting room scenario can have a significant influence on the wave propagation at 300 GHz. Thus, such objects can provide opportunities for eavesdropping signals even at unexpected locations outside of the main lope of the antenna diagram and behind the transmitter and cannot be neglected.