Continuous-variable measurement-device-independent quantum key distribution using squeezed states

Abstract

A continuous-variable measurement-device-independent quantum key distribution (CV-MDI QKD) protocol using squeezed states is proposed where the two legitimate partners send Gaussian-modulated squeezed states to an untrusted third party to realize the measurement. Security analysis shows that the protocol can not only defend all detector side channels, but also attain higher secret key rates than the coherent-state-based protocol. We also present a method to improve the squeezed-state CV-MDI QKD protocol by adding proper Gaussian noise to the reconciliation side. It is found that there is an optimal added noise to optimize the performance of the protocol in terms of both key rates and maximal transmission distances. The resulting protocol shows the potential of long-distance secure communication using the CV-MDI QKD protocol.

Noiseless Linear Amplifiers in Entanglement-Based Continuous-Variable Quantum Key Distribution

“…The schematic of the entanglement-based CV-QKD protocol with an untrusted relay is shown in Figure 2a. This is inspired by the scheme of [31] and represents a modified entanglement-based version of the CV-QKD protocols proposed by [32][33][34][35]. It can be described as follows:…”

“…The goal of full device-independent QKD is the removal of the requirement that Alice and Bob need to trust their devices.In this paper, we consider two kinds of entanglement-based CV-QKD protocols in untrusted scenarios: an entanglement distribution protocol with an untrusted source and an entanglement swapping protocol with an untrusted relay. The latter protocol is inspired by [31] and corresponds to the entanglement-based version of the CV-QKD protocols described in [32][33][34][35]. In particular, we consider a symmetric formulation where the two legitimate partners both modify their data during the classical data post-processing stage.To improve the maximal transmission distances of these two schemes, we consider the use of two noiseless linear amplifiers (NLAs) [36], one at Alice's side and one at Bob's side.…”

Transferring of Continuous Variable Squeezed States in 20 km Fiber

“…Therefore, an effective way for transferring a quantum state in a long-distance channel is necessary for the construction of CV quantum information network. Optical fiber and free space are two main quantum channels used for the exchange of long-distance quantum information [23][24][25][26][27][28]. Optical fiber is the more suitable channel for the transmission of quantum information due to its lower loss and higher reliability.…”

Finite-size analysis of continuous-variable measurement-device-independent quantum key distribution

“…In 2012, Jouguet et al [28] researched the finitesize effect of CV-QKD protocol on the secret key rate in the case of practical detections. So far, the security of the CV-MDI QKD protocol in the asymptotic scenario has been demonstrated [24,25,[29][30][31]. But the feasibility of CV-MDI QKD protocol under finite-size effect has not yet been confirmed.…”