Fundamental research in quantum networks and cryptography – FREQUENCY

In an increasingly connected and globalized world, the notion of security is an imperative, therefore making cryptography a very important research field. In the past two decades, it has been suggested and successfully demonstrated that cryptographic systems that rely on the fundamental laws of quantum physics to ensure the secrecy of transmitted messages offer unprecedented levels of security compared to classical cryptosystems. Research in this field, however, has mainly focused on individual point-to-point links, whose performance in terms of range and user connectivity is inherently limited by the nature of the transmission medium and the implemented protocols. These limitations can be overcome with the advent of quantum cryptography networks. It is therefore now essential to study such networks from both a fundamental and practical point of view, and explore the new capabilities that these networks can offer. This is the goal of the proposed project. Within the general framework of establishing the link between quantum networks and cryptography, we want to look in this project at several different questions that arise in this context. First, we want to develop optimization procedures related to protocols implemented on quantum key distribution networks, network topology, and corresponding cost factors, for network structures that are currently available, or will be available in the near future. In parallel, we would like to define and identify cryptographic primitives, other than quantum key distribution, which can offer advantages in advanced networks such as hybrid classical and quantum structures or fully quantum networks containing quantum repeaters. Finally, we want to study fundamental issues related to guaranteeing the security assurance of quantum cryptosystems that form the building block of any quantum cryptography network. By addressing the above issues, which are all intrinsically linked, we hope to open the way to an entirely new vision of quantum communication systems, and bring this field much closer to the reality of current communication and computer networks. Although our project is mostly of fundamental nature, through links with industrial partners and experimental groups, we expect that our results will lead to specific cryptographic applications and practical solutions for developers of quantum cryptosystems and telecommunication operators wishing to implement quantum cryptography networks, and thus can have a major impact on tomorrow?s secure communications.