arXiv subjects

Damien Stucki

Publications and source records attributed to Damien Stucki.

5 recordsLinked to original sources

arXiv2008

High speed coherent one-way quantum key distribution prototype

We report the first real world implementation of a Quantum Key Distribution (QKD) system over a 43dB-loss transmission line in the Swisscom fibre optic network. The QKD system is capable of continuous and autonomous operation and uses the coherent one-way (COW) protocol. This system brings together three key concepts for future QKD systems: a simple high-speed protocol; high performance detection; and integration, both at the component level as well for connectivity with standard fibre networks. Here, we show laboratory and field trial results for this system. The full prototype version uses InGaAs/InP avalanche photodiodes (APDs) and was laboratory tested up to 150km, with a 10-hour exchange averaging around 2kbps of real-time distilled secret bits over 100km. In the field trials, we obtained average distribution rates, during 3 hours, of 2.5bps over a 43dB-loss line of 150km, when using superconducting single photon detectors (SSPDs).

quant-ph↗

arXiv2005

Fast and simple one-way Quantum Key Distribution

We present and demonstrate a new protocol for practical quantum cryptography, tailored for an implementation with weak coherent pulses to obtain a high key generation rate. The key is obtained by a simple time-of-arrival measurement on the data line; the presence of an eavesdropper is checked by an interferometer on an additional monitoring line. The setup is experimentally simple; moreover, it is tolerant to reduced interference visibility and to photon number splitting attacks, thus featuring a high efficiency in terms of distilled secret bit per qubit.

quant-ph↗

arXiv2005

A Fabry-Perot like two-photon interferometer for high-dimensional time-bin entanglement

We generate high-dimensional time-bin entanglement using a mode-locked laser and analyze it with a 2-photon Fabry-Perot interferometer. The dimension of the entangled state is limited only by the phase coherence between subsequent pulses and is practically infinite. In our experiment a pico-second mode-locked laser at 532 nm pumps a non-linear potassium niobate crystal to produce photon pairs by spontaneous parametric down-conversion at 810 and 1550 nm.

quant-ph↗

arXiv2004

Towards practical and fast Quantum Cryptography

We present a new protocol for practical quantum cryptography, tailored for an implementation with weak coherent pulses. The key is obtained by a very simple time-of-arrival measurement on the data line; an interferometer is built on an additional monitoring line, allowing to monitor the presence of a spy (who would break coherence by her intervention). Against zero-error attacks (the analog of photon-number-splitting attacks), this protocol performs as well as standard protocols with strong reference pulses: the key rate decreases only as the transmission $t$ of the quantum channel. We present also two attacks that introduce errors on the monitoring line: the intercept-resend, and a coherent attack on two subsequent pulses. Finally, we sketch several possible variations of this protocol.

quant-ph↗

arXiv2001

Photon counting for quantum key distribution with Peltier cooled InGaAs/InP APD's

The performance of three types of InGaAs/InP avalanche photodiodes is investigated for photon counting at 1550 nm in the temperature range of thermoelectric cooling. The best one yields a dark count probability of $% 2.8\cdot 10^{-5}$ per gate (2.4 ns) at a detection efficiency of 10% and a temperature of -60C. The afterpulse probability and the timing jitter are also studied. The results obtained are compared with those of other papers and applied to the simulation of a quantum key distribution system. An error rate of 10% would be obtained after 54 kilometers.

quant-ph↗