Secrecy of quantum key distribution in case passive basis choice with detection efficiency mismatch

Ivchenko E.I., Trushechkin A.S., Khmelev A.V., Kurochkin V.L.

For Russian citation (Opticheskii Zhurnal):

Ивченко Е.И., Трушечкин А.С., Хмелев А.В., Курочкин В.Л. Секретность систем квантового распределения ключей с пассивным выбором базиса при разной эффективности детекторов // Оптический журнал. 2025. Т. 92. № 7. С. 87–94. http://doi.org/10.17586/1023-5086-2025-92-07-87-94

Ivchenko E.I., Trushechkin A.S., Khmelev A.V., Kurochkin V.L. Secrecy of quantum key distribution in case passive basis choice with detection efficiency mismatch [in Russian] // Opticheskii Zhurnal. 2025. V. 92. № 7. P. 87–94. http://doi.org/10.17586/1023-5086-2025-92-07-87-94

For citation (Journal of Optical Technology):

Abstract:

Subject of study. Different quantum efficiencies of single-photon detectors in quantum key distribution setups using the BB84 protocol with passive basis choice. Aim of study. Determination of the generation rate and security of the final key for quantum cryptography systems depends on the difference in the efficiency of detectors. Derivation of an analytical expression for estimating the secret key generation rate in quantum communication systems with passive basis choice and taking into account different detector efficiency. Method. The calculation of the secret key is carried out by dividing the received data into bases and separately processing each set, after that, the obtained estimates of the secret key are summed up. Main results. An analytical method for estimating the secret key rate with different detector efficiencies for systems with passive basis choice was provided. The satellite-to-ground communication channel was modeled using the parameters of the Zvenigorod Observatory. The developed theory for accounting for different detector efficiencies is applied to a model of a satellite quantum key distribution setup, and the value of the secret key sequence generated in one communication session with the satellite is obtained, equal to 300 Kbit. Practical significance. The results allow us to take into account the effect of different detector efficien-cies when estimating the length of a secret sequence for quantum key distribution systems and to increase their reliability in practice.

Keywords:

quantum cryptography, quantum key distribution, single photon detectors

Acknowledgements:

the work was carried out with the support of the Ministry of Education and Science of the Russian Federation within the framework of the Strategic Academic Leadership Program “Priority 2030” (Strategic Project “Quantum Internet”).

OCIS codes: 270.0270, 040.5570

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