Asymmetric MDI-QKD: Enhancing Security and Performance in Quantum Networks

Measurement-device-independent quantum key distribution (MDI-QKD) completely closes the security loopholes caused by the imperfection of device at the detection terminal. Commonly, the symmetric MDI-QKD model is widely used in simulation and experiment. This scenario is far from a real quantum network, where the losses of channels connecting each user are quite different. To adapt such a feature, an asymmetric MDI-QKD model is proposed. How to improve the performance of asymmetric MDI-QKD also becomes an important research direction. In this work, an advantage distillation (AD) step can further improve the performance of asymmetric MDI-QKD without changing the original key distribution process. Simulation results show that the AD method can improve the secret key rate and transmission distance. Therefore, this scheme will greatly promote the development of future MDI-QKD networks.