Dual-phase-modulated plug-and-play measurement-device-independent continuous-variable quantum key distribution

We suggest a novel scheme for measurement-device-independent (MDI) continuous-variable quantum key distribution (CVQKD) by integrating plug-and-play (PP) configuration with dual-phase modulation (DPM). With these techniques, MDI-CVQKD system has the ability to overcome a number of impractical problems with no extra performance penalty. In particular, the synchronous loophole of different lasers from Alice and Bob can be elegantly eliminated in the plug-and-play configuration, which gives birth to the convenient implementation when comparing to the Gaussian-modulated coherent-state protocol. Moreover, All LO-aimed attacks can be well defended since the local oscillator (LO) is locally generated. By taking advantage of DPM, the performance degeneration caused by the practical polarization-sensitive amplitude modulator can be eliminated. We also derive the security bounds for the proposed scheme against optimal Gaussian collective attacks. By taking the finite-size effect into account, we show that almost all raw keys generated by the proposed scheme can be exploited for the final secret key generation so that the secret key rate can be increased without sacrificing a part of raw keys for parameter estimation. In addition, we give an experimental concept of the proposed scheme which can be deemed guideline for final implementation. (c) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement