Best-Practice Criteria for Practical Security of Self-Differencing Avalanche Photodiode Detectors in Quantum Key Distribution


Type
Article
Change log
Authors
Koehler-Sidki, A 
Dynes, JF 
Lucamarini, M 
Roberts, GL 
Sharpe, AW 
Abstract

Fast gated avalanche photodiodes (APDs) are the most commonly used single photon detectors for high bit rate quantum key distribution (QKD). Their robustness against external attacks is crucial to the overall security of a QKD system or even an entire QKD network. Here, we investigate the behavior of a gigahertz-gated, self-differencing InGaAs APD under strong illumination, a tactic Eve often uses to bring detectors under her control. Our experiment and modelling reveal that the negative feedback by the photocurrent safeguards the detector from being blinded through reducing its avalanche probability and/or strengthening the capacitive response. Based on this finding, we propose a set of best-practice criteria for designing and operating fast-gated APD detectors to ensure their practical security in QKD.

Description
Keywords
quant-ph, quant-ph
Journal Title
Physical Review Applied
Conference Name
Journal ISSN
2331-7019
2331-7019
Volume Title
9
Publisher
American Physical Society (APS)
Sponsorship
Engineering and Physical Sciences Research Council (1678703)