Topology-Hiding Connectivity-Assurance for QKD Inter-Networking

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Abstract:While QKD ensures information-theoretic security at the link level, real-world deployments depend on trusted repeaters, creating potential vulnerabilities. In this paper, we thus introduce a topology-hiding connectivity assurance protocol to enhance trust in quantum key distribution (QKD) network infrastructures. Our protocol allows network providers to jointly prove the existence of a secure connection between endpoints without revealing internal topology details. By extending graph-signature techniques to support multi-graphs and hidden endpoints, we enable zero-knowledge proofs of connectivity that ensure both soundness and topology hiding. We further discuss how our approach can certify, e.g., multiple disjoint paths, supporting multi-path QKD scenarios. This work bridges cryptographic assurance methods with the operational requirements of QKD networks, promoting verifiable and privacy-preserving inter-network connectivity.

Subjects:

Cryptography and Security (cs.CR); Quantum Physics (quant-ph)

Cite as: arXiv:2604.01876 [cs.CR]

(or arXiv:2604.01876v1 [cs.CR] for this version)

https://doi.org/10.48550/arXiv.2604.01876

arXiv-issued DOI via DataCite (pending registration)

Submission history

From: Stephan Krenn [view email] [v1] Thu, 2 Apr 2026 10:30:43 UTC (125 KB)