A real-time QKD system based on FPGA
This work addresses the need for practical, real-time QKD systems for secure communication, though it appears incremental as it builds on existing FPGA-based methods.
The authors developed a real-time Quantum Key Distribution (QKD) system using FPGA to handle secure key extraction processes, achieving a final key rate of 17 kbps over a 20 km optical fiber with a 20 MHz photon repetition frequency.
A real-time Quantum Key Distribution System is developed in this paper. In the system, based on the feature of Field Programmable Gate Array (FPGA), secure key extraction control and algorithm have been optimally designed to perform sifting, error correction and privacy amplification altogether in real-time. In the QKD experiment information synchronization mechanism and high-speed classic data channel are designed to ensure the steady operation of the system. Decoy state and synchronous laser light source are used in the system, while the length of optical fiber between Alice and Bob is 20 km. With photons repetition frequency of 20 MHz, the final key rate could reach 17 kbps. Smooth and robust operation is verified with 6-hour continuous test and associated with encrypted voice communication test.