Satellite-based quantum key distribution (QKD)

The group focuses on advancing practical and operational satellite-based quantum key distribution (QKD) to bring science into real-world applications. The challenges towards this goal range from basic quantum theory science, proof of principle and breadboard tests, space and software engineering up to the tasks of integration testing and standardization.

Currently, the team has the scientific lead within the Eagle-1 project, a dedicated European satellite mission funded by ESA with over 20 collaborators under the lead of the satellite service provider SES. Its goal is to demonstrate QKD from Low Earth Orbit (LEO) using a phase-encoded BB84 decoy state QKD protocol. This project exemplifies the collaboration of science and engineering, combining quantum communication protocols with satellite infrastructure development. The system consisting of a satellite and two ground stations will demonstrate key exchange between two ground users in a final in-orbit validation. The mission lays the groundwork for a QKD service to secure Europe’s critical infrastructure and enable intercontinental communication.

The group has the responsibility of the QKD protocol development as well as developing and building the quantum receiver prototypes. The group addresses key satellite-based QKD challenges, including single-photon time synchronization, Doppler compensation, atmospheric effects, high losses, and phase locking.

Future prospects are to investigate more existing and newer QKD protocols and security proofs and to explore their potential advantages and how to employ them in QKD satellite systems.