We assess the overall performance of our quantum key distribution (QKD) system implementing the measurement-device-independent (MDI) protocol using components with varying capabilities such as different single photon detectors and qubit preparation hardware. We experimentally show that superconducting nanowire single photon detectors allow QKD over a channel featuring 60 dB loss, and QKD with more than 600 bits of secret key per second (not considering finite key effects) over a 16 dB loss channel. This corresponds to 300 km and 80 km of standard telecommunication fiber, respectively. We also demonstrate that the integration of our QKD system into FPGA-based hardware (instead of state-of-the-art arbitrary waveform generators) does not impact on its performance. Our investigation allows us to acquire an improved understanding of the trade-offs between complexity, cost and system performance, which is required for future customization of MDI-QKD. Given that our system can be operated outside the laboratory over deployed fiber, we conclude that MDI-QKD is a promising approach to information-theoretic secure key distribution.
@article{arxiv.1501.07307,
title = {Measurement-device-independent quantum key distribution: from idea towards application},
author = {Raju Valivarthi and Itzel Lucio-Martinez and Philip Chan and Allison Rubenok and Caleb John and Daniel Korchinski and Cooper Duffin and Francesco Marsili and Varun Verma and Mathew D. Shaw and Jeffrey A. Stern and Sae Woo Nam and Daniel Oblak and Qiang Zhou and Joshua A. Slater and Wolfgang Tittel},
journal= {arXiv preprint arXiv:1501.07307},
year = {2015}
}