Darmstadt 2008 – scientific programme
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Q: Fachverband Quantenoptik und Photonik
Q 28: Poster Quanteninformation
Q 28.11: Poster
Tuesday, March 11, 2008, 16:30–19:00, Poster C2
QKD Decoy Protocol with Photon Number Measurement — •Malte Avenhaus1, Wolfgang Mauerer1, Patrick Bronner2, and Christine Silberhorn1 — 1Max Planck Research Group IOIP, Günther-Scharowsky-Str. 1 / Bau 24, 91058 Erlangen — 2Friedrich-Alexander-Universität Erlangen Nürnberg, Staudtstr. 7, 91058 Erlangen
Quantum decoy protocols provide an advantageous alternative to various conventional QKD protocols. Decoy protocols feature a lower threshold for detecting a potential eavesdropper and thus increase the secure communication distance. The principle of operation is that Alice uses photons as quantum carriers and interposes a decoy photon distribution within the signal.
We investigate the experimental implementation of a decoy protocol. On Alice’s side, a pulsed laser beam pumps a PDC process in a PPKTP wave-guide. The PDC process shows high source brightness and converts photons from the pump mode at 1550nm in signal and idler mode of 800nm and 1550nm respectively. The signal mode is particularly apt for photon number measurements on Alice’s side, whereas the idler mode is used for low loss transmission via telecommunication fibre to recipient Bob. The decoy subset during communication may be chosen a posteriori while performing a classical communication.