Drone-based Quantum Key Distribution*

Recent advances in quantum memories point to the future viability of quantum networking, including quantum cryptography. To be truly multi-purpose, future quantum communication networks should consist of a variety of platforms, e.g., airplanes, drones, and ships, though the motion of these platforms precludes the use of fiber-based approaches to quantum cryptography; free-space quantum key distribution (QKD) systems have historically been rather bulky. Small moving platforms, such as multirotor drones, are ideal for reconfigurable networks in both urban and rural environments but are only capable of supporting lightweight payloads (< 10 kg). Here we discuss our current progress in developing a reconfigurable network of two or more small multi-rotor drones implementing a modified BB84 quantum key distribution protocol over a free-space optical channel. This requires the development of fast and lightweight sources of polarized photons with no side channel leakage, miniaturization of time-tagging electronics and single-photon detectors, and the development of a robust signal acquisition and pointing and tracking system.