Qubit-Based Synchronization Algorithm for Measurement-Device-Independent Quantum Key Distribution

Measurement-device-independent quantum key distribution (MDI-QKD) is considered one of the most promising protocols due to its high performance and security. To implement the MDI-QKD system in practice, clock synchronization is a crucial step to correctly generate the secret keys. However, as practical applications advance, the complexity and cost of synchronization have become significant challenges for the implementation of MDI-QKD. In this study, we introduce a qubit-based synchronization algorithm specifically designed for MDI-QKD. By utilizing the property of Hong-Ou-Mandel interference, we achieve clock synchronization between parties of MDI-QKD without the need for additional hardware. The cost-effectiveness and simplicity of this approach are expected to significantly facilitate the practical deployment of MDI-QKD.