High‐Speed Privacy Amplification Scheme for Quantum Key Distribution

ABSTRACT Privacy amplification (PA) is a crucial step in Quantum Key Distribution (QKD). The original key with the risk of information leakage is transformed into the final key with information theory security through PA. The speed of PA limits the overall rate of QKD. This article proposes a novel approach of PA. This method connects Square Hash (SQH) and number‐theory transform Hash (NH) in series and utilizes number‐theoretic fast Fourier transform (NTT) to reduce its computational complexity to . This paper provides a security proof based on information theory. To implement the scheme based on field programmable gate arrays (FPGA), this paper designed a new architecture to support it. Several optimization techniques of the PA scheme have been implemented to accelerate computation speed and reduce resource consumption, including parallel NTT computation unit and pipelined carry unit, etc. This architecture is also applicable to other similar PA scheme. The experiment result achieves a higher throughput than the compared FPGA‐based works. After further optimization of the architecture, the clock frequency reaches 250 MHz, and the throughput exceeds 10 Gbps, achieving more than 6 times higher than the fastest PA solution among the compared works.