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A novel decoy state BB84 QKD transmission scheme using optical-switch-based polarization multiplexing

De-Wei Liao, Yuan-Ren Yeh, Chong-You Hong, Jhih-Heng Yen, Chin-Cheng Hu, Yu-Ping Yu, Yu‐Han Hung

Published Apr 5, 2024• 0 citations

Abstract

Due to today's communication demands, we require a highly secure key rate. However, there is still a significant room for improvement. This paper proposes a method to enhance the decoy state BB84 Quantum Key Distribution (QKD) on the transmitter side. Since some studies have indicated that the switching speed of optical switches can reach the attosecond level, we aim to utilize optical switches to generate more qubits per unit of time. Due to the need for proper experimental equipment and single photon detectors, we could only conduct a proof-of-concept experiment to validate our idea. We also generate the electrical signals using Python Productivity for ZYNQ (PYNQ) to control the intensity modulator for creating decoy states and our switch design for generating polarization states. Our experimental results clearly distinguish between decoy states and polarization states. Furthermore, it also aligns with our simulation results. The advantages of our transmitter design include: a) Using an optical switch to increase the critical rate. b) Enhancing system stability by employing a single laser and a fixed polarization generation instrument. c) FPGA is easily integrated with other systems. d) User-friendly key generation and comparison are done through Python. In addition, while this paper focuses on the study of decoy-state BB84, it is also feasible to consider the utilization of optical switches in other QKD protocols.

DOI: 10.1117/12.3022656

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