Secure practical indoor optical wireless communications using quantum key distribution

Abstract: Quantum Key Distribution (QKD) can guarantee security for practical indoor optical wireless environments. The key challenges are to mitigate artificial lighting and ambient light at the receiver. A new spectral region for QKD is proposed and an ideal QKD link model is simulated with experimental ambient light power measurements. Simulation, modelling, and analysis indicates that the carbon dioxide and water absorption band (1370 nm) is a new wavelength region for QKD operation in indoor optical wireless environments. For a feasible QKD link, approximately 20 dB of signal to noise ratio (SNR) is required and a maximum quantum bit error rate (QBER) of 11% when using the BB84 protocol. Links in the new spectral region with a FOV of several degrees are feasible, depending on available components.