| Security of Trusted Repeater Quantum Key Distribution Networks
- Louis Salvail, Momtchil Peev, Eleni Diamanti, Romain Alleaume, Norbert Lutkenhaus, Thomas Laenger
- 2009
Abstract
A Quantum Key Distribution (QKD) network is an infrastructure capable of performing long-distance and high-rate secret key agreement with information-theoretic security. In this paper we study security properties of QKD networks based on trusted repeater nodes. Such networks can already be deployed, based on current technology. We present an example of a trusted repeater QKD network, developed within the SECOQC project. The main focus is put on the study of secure key agreement over a trusted repeater QKD network, when some nodes are corrupted. We propose an original method, able to ensure the authenticity and privacy of the generated secret keys.
Note
Read for the A-0127 review, 2026-09-28, section 4 in full. The founding analysis ITU-T X.1713 clause 9 cites for its corrupted-node statement, and sharper than that one-line summary. Topology condition: a corrupted node on every quantum path between the endpoints makes key agreement impossible (clause 4.3). The denial branch as a one-node result: one corrupted node suffices to stop the endpoints agreeing on an identical key, by sending classical messages other than those expected (clause 4.3). Why the failure is silent: without a pre-shared authentication key they cannot detect that they do not share a private key (clause 4.3). And the founding form of multi-path relay: two disjoint paths yield a key unknown to any single node, and over t paths the key is secure unless all t collaborate (clause 4.1). The operator reports a published version in the Journal of Computer Security; the preprint names no journal, volume or DOI, so none is recorded here.