DESIGN AND SECURITY OF QUANTUM KEY DISTRIBUTION

Abstract

Quantum Key Distribution (QKD) is one of the most mature applications of quantum technologies. It brings provable high levels of security to secret communication. In this thesis, we improved two technical results and used them to analyse a few QKD protocols and to optimise their design parameters. The first one is a generalisation of the decoy-states technique to use both source and detector modulation. The second one is a generalisation of the universal squashing framework to multimode protocols. The application examples include the security analysis of single photon QKD with practical light sources and detectors, the analysis of the coherent-one-way QKD protocol with a fully passive setup, the analysis of measurement device-independent and twin-field QKD protocols and the analysis of a protocol based on uncharacterised homodyne detection.