EU: Optical Metrology for Quantum-Enhanced Secure Telecommunication

The goal of this project is to accelerate the development and commercial success of Quantum Key Distribution (QKD) technologies. This presents a number of metrological challenges, which result from the current and predicted development and deployment trajectories of QKD technologies. The current state-of-the-art for QKD industry uses fibre communications (typically providing hundred-kilometre point-to-point QKD links). The development of a worldwide network can be achieved only through ground-air (ground-satellite) communication and this will be the next stage for QKD R&D efforts. Fibre and free-space QKD systems use real devices, which do not have the ideal characteristics envisaged by the initial QKD concept. This means that those practical systems can be vulnerable to one or more of the many quantum hacking attacks proposed and/or demonstrated. Counter-measures against these attacks have already been identified, but their effectiveness should be ensured by rigorous characterisation of the optical components – this will be addressed by the consortium. Another approach against these attacks is represented by entanglement-based QKD techniques such as e.g. device-independent (DI) QKD, measurement-device-independent (MDI) QKD, etc. The development of entanglement characterisation and quantification techniques is essential in order to provide the metrological framework for next-generation (entanglement-based) QKD systems. Addressing these challenges requires collaboration with industrial QKD providers, network providers and standardization bodies. Following the considerations above, the key objectives addressed in this JRP are: 1. The development of efficient measurement techniques for characterisation of counter-measures to side-channel and Trojan-horse attacks in fibre-based QKD systems, and the realisation of pilot measurement comparisons to validate the techniques developed 2. The development of dedicated calibration techniques for new high-speed single-photon detectors for fibre-based QKD 3. The development of measurement techniques for the characterisation of the components of free-space QKD systems for ground-air communication, and the realisation of pilot measurement comparisons to validate techniques developed 4. The establishment of the foundations of the metrology required for QKD systems based on the entanglement of photons 5. The definition of best-practice for the efficient and cost-effective measurements needed by industry and users, and the contribution to international guidelines and standards In addition, the project will organise workshops and/or conferences, present the project’s results at conferences and in high-impact-factor scientific journals. Knowledge will also be disseminated by developing training courses and an advisory board consisting also of industry stakeholders will regularly meet to exchange information with the consortium and ensure that the project is delivering relevant results.