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Posterior laser-locking technique for MDI-QKD
St. Petersburg Polytechnical University Journal: Physics and Mathematics. 2022. Vol. 15. No. 3.3. P. 194–197.
Mekhtiev E. E., Gerasin I. S., Rudavin N. V., Duplinsky A. V., Kurochkin Y. V.
We present a novel soft-ware based method to ensure independent lasers mutual coherence required for practical realization of advanced Measurement Device Independent Quantum Key Distribution (MDI-QKD) protocols. Proof of principle experiment has proved validity of the method, providing mutual coherence time while upper bound dictated by uncontrollable phase drift in optical fiber being ~ 100 µs.
Filyaev A. A., Losev A. V., Zavodilenko V. V. et al., St. Petersburg Polytechnical University Journal: Physics and Mathematics 2023 Vol. 16 No. 3.1 P. 237–241
In this paper an important parameter of single-photon detectors, such as quantum efficiency, is considered. Errors in determining this parameter lead to significant errors in the parameters of a quantum key distribution system, where such detectors find their application. Three models are proposed to estimate photon detection efficiency or quantum efficiency and their main advantages ...
Added: May 6, 2026
Automated verification of countermeasure against detector-control attack in quantum key distribution
Acheva P., Zaitsev K., Zavodilenko V. V. et al., EPJ QUANTUM TECHNOLOGY 2023 Vol. 10 No. 1 Article 22
Attacks that control single-photon detectors in quantum key distribution using tailored bright illumination are capable of eavesdropping the secret key. Here we report an automated testbench that checks the detector’s vulnerabilities against these attacks. We illustrate its performance by testing a free-running detector that includes a rudimentary countermeasure measuring an average photocurrent. While our testbench ...
Added: April 19, 2024
Zavodilenko V. V., Losev A. V., Filyaev A. A. et al., Optoelectronics, Instrumentation and Data Processing 2023 Vol. 59 P. 148–155
Automated measuring stand (AMS) for evaluation of the operational parameters of single-photon detectors (SPD) has been developed together with the software that implements the method of evaluating SPD efficiency parameters from the experimental data measured with AMS. We present graphical interface of the software, which allows generating recommendations for configuring operation mode of the detector ...
Added: September 1, 2023
Gerasin I. S., Mekhtiev E. E., Maksimova E. L. et al., St. Petersburg Polytechnical University Journal: Physics and Mathematics 2022 Vol. 15 No. 3.3 P. 198–201
The preparation of indistinguishable quantum states by remote users is one of the crucial tasks in MDI-QKD. To solve this problem, laser injection techniques or modulation of the CW laser on the transceiver side are used. These techniques require a complex setup or a pair of modulators. Here we present a different setup for generating ...
Added: May 11, 2023
N. V. Rudavin, Gerasin I. S., Mekhtiev E. E. et al., St. Petersburg Polytechnical University Journal: Physics and Mathematics 2022 Vol. 15 No. 3.2 P. 56–60
Commercial fiber quantum key distribution systems require the implementation of a protocol for synchronizing the frequency synthesizers of the transmitter and receiver nodes. Frequency mismatch may be due to temperature fluctuations, mechanical effects and imperfections in the technological processes. In this work, an algorithm for automatically adjusting Alice's and Bob's frequency to Charlie's frequency is ...
Added: December 19, 2022
Rudavin N V, Gerasin I. S., Mekhtiev E. E. et al., Journal of Physics: Conference Series 2021 Vol. 2086 Article 012098
Polarization-encoding fiber QKD requires compensation of polarization distortion caused by birefringence in optical fiber. Solving this task inevitably requires losing some effectiveness in terms of the final key rate. In this work, a time-division multiplexing protocol for polarisation calibration is suggested. This protocol was implemented in a QRate commercial QKD fiber system, utilizing BB84-protocol. Parameters ...
Added: May 18, 2022
Mekhtiev E. E., Gerasin I. S., Rudavin N V et al., Journal of Physics: Conference Series 2021 Vol. 2086 Article 012092
The crucial task for polarization-encoding fiber QKD is to compensate polarization drift occurring in a quantum channel. To solve this problem, the receiver usually uses a polarization controller. For proper operation, this device must be efficiently managed in real-time. In this work, a gradient-descent-based algorithm is proposed to solve this problem. The algorithm was implemented ...
Added: May 18, 2022
Elezov M., Roman Ozhegov, Gregory Goltsman et al., Optics Express 2019 Vol. 27 No. 21 P. 30979–30988
We present an active anti-latching system for superconducting nanowire single-photon detectors. We experimentally test it against a bright-light attack, previously used to compromise security of quantum key distribution. Although our system detects continuous blinding, the detector is shown to be partially blindable and controllable by specially tailored sequences of bright pulses. Improvements to the countermeasure ...
Added: October 23, 2019
Moshkova M., Divochiy A., Morozov P. et al., Journal of the Optical Society of America B: Optical Physics 2019 Vol. 36 No. 3 P. B20–B25
The use of improved fabrication technology, highly disordered NbN thin films, and intertwined section topology makes it possible to create high-performance photon-number-resolving superconducting single-photon detectors (PNR SSPDs) that are comparable to conventional single-element SSPDs at the telecom range. The developed four-section PNR SSPD has simultaneously an 86±3%86±3% system detection efficiency, 35 cps dark count rate, ∼2 ns∼2 ns dead time, and maximum ...
Added: January 9, 2019