Radiofrequency emanations of a single-photon detector
John J. Pantoja, Alfonso Tello, Dimitris E. Anagnostou, J. Kirrane, Mark Stonehouse, A. Koehler-Sidki, Michele Natrella, Ross J. Donaldson · IET conference proceedings. · 2023
Quantum key distribution (QKD) offers the possibility of information theoretic secure key establishment. However, non-ideal behaviour of some components used in practical implementations causes security risks and loopholes that need to be addressed. Previously identified loopholes have resulted in changes to hardware and the invention of new QKD protocols. In this document, we report an investigation into the eavesdropping risk due to out-of-band radiofrequency emanations produced by a QKD receiver. We present experimental results that show a QKD receiver may produce significant pulsed-like emissions that can be detected by a passive eavesdropper antenna to identify clicks in single-photon detectors.