Feasibility of Quantum Key Distribution Between Supersonic Aircraft

Abstract

Quantum key distribution (QKD) leverages the laws of quantum mechanics to enable the secure transfer of information and is the only known method of key exchange capable of providing verifiable security. While commercial optical fibre based QKD links are available, there are presently no free space based commercial solutions. Furthermore, QKD on airborne platforms has only been experimentally verified at low altitudes and at low speeds. We first survey the academic literature to identify gaps in research and establish a foundation for our own study. Subsequently, this study utilises computational modelling to find that continuous variable (CV) QKD is feasible for high-speed airborne platforms and can provide sufficient data rates (> 100 Mb/s without multiplexing) at suitable ranges (≈15 km with full wavefront correction) for typical supersonic aircraft use cases. The implementation of such a system is economically viable as it can utilise relatively low-cost standard devices developed by the telecommunications industry, as opposed to the specialised equipment typically required for discrete variable (DV) QKD protocols. Our results highlight how the current capabilities of such devices impose limits on the performance (data rates and ranges) of airborne QKD systems.