Security Analysis of Unidimensional Continuous-Variable Quantum Key Distribution Using Uncertainty Relations

Abstract

We study the equivalence between the entanglement-based scheme and prepare-and-measure scheme of unidimensional (UD) continuous-variable quantum key distribution protocol. Based on this equivalence, the physicality and security of the UD coherent-state protocols in the ideal detection and realistic detection conditions are investigated using the Heisenberg uncertainty relation, respectively. We also present a method to increase both the secret key rates and maximal transmission distances of the UD coherent-state protocol by adding an optimal noise to the reconciliation side. It is expected that our analysis will aid in the practical applications of the UD protocol.

Unidimensional continuous-variable measurement-device-independent quantum key distribution

“…Theoretically, before we derive the explicit expressions of the parameters, we have to consider the relationship of the two unknown parameters η A,p and A,p in p quadrature. Bounded by the Heisenberg uncertainty principle to meet the requirement of physicality, the two unknown parameters should satisfy the parabolic equation constraint [56]:…”

“…The modulation variance Vm is in shot noise unit N 0 . The reverse reconciliation is 0.98 [56], the excess noise are A,x = B,x = 0.002 [44], the quantum channel loss is 0.2 dB/km. From top to bottom, the total transmission distance (L = L AC + L BC ) is 2 km, 3 km, 4 km, 5 km.…”

“…Compared to the conventional symmetrical GMCS CV-QKD protocols, the asymmetrical UDCV-QKD protocols only requires the sender to use one simple modulator to perform a single-quadrature modulation instead of two modulators, which would even avoid to create a hole in the center of the Gaussian probability distribution [53]. Moreover, the security analysis [54][55][56] and several experimental realizations [57] were carried out to validate the feasibility of UDCV-QKD protocols.…”

Entropy in Foundations of Quantum Physics

“…The contribution by Wang et al [ 22 ] is the third paper, after [ 11 ] and [ 19 ], on continuous variable quantum key distribution. In this paper [ 22 ], the authors study a unidimensional version of that protocol. Their main result is that adding optimal noise to the receiver improves the resistance of the protocol to excess noise.…”

Entropy in Foundations of Quantum Physics

“…The contribution by Wang et al [22] is the third paper, after [11] and [19], on continuous variable quantum key distribution. In this paper [22], the authors study a unidimensional version of that protocol.…”