The cryptography team at AIT published a paper as part of the ARES 2025 workshop SECPID. In that paper the team addresses the trusted node issue of QKD Networks especially relevant for the KMS layer. One possible mitigation strategy is to use multi-path techniques, which is the main focus of the paper published via Springer.
The abstract of the paper reads:
“Quantum Key Distribution (QKD) networks are receiving growing attention by researchers and funding agencies, with the largest projects spanning hundreds of kilometers and large, multi-national initiatives well under way. The growing scale of QKD networks poses some extra challenges, in particular due to the current impossibility of establishing end-to-end security between nodes: for large distances, reliance on intermediate trusted nodes is required, an aspect which increases the attack surface of QKD networks. A possible mitigation strategy for this problem lies in leveraging the complexity of the network: by making use of multiple paths and applying techniques issued from cryptography and/or error-correcting theory, it is possible to mitigate some attacks and force an adversary to compromise more nodes in the network.
This paper discusses relevant approaches to leverage multi-path aspects of QKD networks for increased security, analyzing the different security assumptions, guarantees, and performance of different techniques, and presenting their applicability to the different networks.”