Scalable QKD Postprocessing System With Reconfigurable Hardware Accelerator

Key distillation is an essential component of every quantum key distribution (QKD) system because it compensates for the inherent transmission errors of a quantum channel. However, the interoperability and throughput aspects of the postprocessing components are often neglected. In this article, we propose a high-throughput key distillation framework that supports multiple QKD protocols, implemented in a field-programmable gate array (FPGA). The proposed design adapts a MapReduce programming model to efficiently process large chunks of raw data across the limited computing resources of an FPGA. We present a novel hardware-efficient integrated postprocessing architecture that offers dynamic error correction, mutual authentication with a physically unclonable function, and an inbuilt high-speed encryption application that utilizes the key for secure communication. In addition, we have developed a semiautomated high-level synthesis framework that is compatible with any discrete variable QKD system, showing promising speedup. Overall, the experimental results demonstrate a noteworthy enhancement in scalability achieved through the utilization of a single FPGA platform.