Hannover 2010 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
Q: Fachverband Quantenoptik und Photonik
Q 56: Quantum Information: Quantum Communication II
Q 56.1: Vortrag
Freitag, 12. März 2010, 10:30–10:45, A 310
Experimental demonstration of an exploit of detector deadtimes in QKD — •Sebastian Nauerth1, Henning Weier1, Harald Krauss1, Martin Fürst1, Markus Rau1, and Harald Weinfurter1,2 — 1Ludwig-Maximilians-Universität München — 2Max-Planck-Institut für Quantenoptik Garching
The security of real world quantum key distribution (QKD) systems depends heavily on their thorough implementation. Eavesdroppers can benefit from technical imperfections to gain information on the generated keys. Because some of these attacks are beyond the scope of current security proofs, they possibly will remain unnoticed by the legitimate communicating parties.
One of these imperfections, which is common to almost all QKD systems, is the so called dead time of most single photon detectors (SPD), i. e. the time for which an SPD is rendered inactive after a detection event.
We present our experimental results of a very simple yet highly effective method to exploit this detector imperfection by sending carefully timed blinding pulses into the detectors. Without introducing additional quantum bit errors, thus without being detected by state of the art QKD protocols, an adversary could successfully guess each keybit with a probability greater than 98%. While, in this work, we attack a BB84 system with four detectors, many other schemes are vulnerable to the evesdropping strategy we developed. Yet, we propose an evenly simple and effective countermeasure to inhibit the demonstrated and similar attacks already by the detector electronics.