Quantum Key Distribution in softwarised networks

Quantum Key Distribution (QKD) is a rising field of research that aims at solving a very common problem in computer security: the problem of cryptographic key exchange. Nowadays, key distribution problem is solved leveraging algorithms that allow to dynamically generate common secrets starting from shared information. For these algorithms security lies in the difficulty for an adversary to compute mathematical operations needed to recover the generated secret. Nevertheless, advent of quantum computers represents a huge concern for classical security, since it has been proved capable of solving these operations in polynomial time. QKD represents a possible solution to this problem, since it allows to exchange keys between two distant parties in a way that is considered secure against both classical and quantum attacks. Recent studies focus their attention on protocols and technologies needed to improve QKD between two parties, with little attention to practical integration in real contexts. This work proposes a different approach: QKD is here used in a softwarised network in order to be accessed from different security services or applications that may need it. The goal of this work is to outline main challenges that need to be faced when distributing QKD as a service for multiple clients. A QKD simulator has been developed to understand limits and characteristics of different protocols in such an environment. On the top of it, QKD ETSI standard has been implemented in order to realise a key server capable of distributing quantum distributed keys to different clients. The proposed work provides a new perspective, in which QKD can be used in cloud environments without taking care about the implementation complexity that it carries with it. Moreover, it outlines criticalities and challenges that needs to be faced in order to integrate QKD in such a systems.