Grant: Collaborative Research and Development Grants

The emergence of quantum computers forces us to change the cryptographic infrastructure securing our data storage and communication structures. Quantum Key Distribution (QKD) will be part of this new infrastructure as it can provide implementation security independent of future technological and algorithmic advances. Much conceptional and practical effort has to be made to make QKD compatible with modern optical communication technology to allow adoption of this technology within the broader telecom service provider market. QKD could be used to secure the telecommunication infrastructure or also to provide key management service to end customers. The requirement for the successful adoption will be stable equipment that fits seamless to existing infrastructure and use essentially the same components as the modern classical communication equipment.Over the recent years, immense progress has been made in our ability to analyze the security and performance of quantum key distribution protocols and their optical implementation. Initially the focus was on QKD technology that requires technology able to detect single photons, the smallest amount of light detectable. More recently, QKD systems based on modern homodyne and heterodyne detection technology were developed which use standard optical detection schemes as they are used in modern optical communication. No single-photon detection is required for these protocols, opening potentially the path for cheaper and faster QKD schemes. However, while some idealized situations of these protocols can now be readily analyzed, some desirable protocols, so called discrete-modulated continuous variable protocols, have resisted yet a full security analysis due to missing security proof techniques. In this proposal we will be developing new tools and methods for security proofs that are applicable to these desirable protocols. Only with clear formulated security proofs will we be able to deploy the new schemes to secure our infrastructure.