Abstract
Establishing global secure networks is a potential implementation of continuous-variable quantum key distribution (CVQKD) but it is also challenged with respect to long-distance transmission. The discrete modulation (DM) can make up for the shortage of transmission distance in that it has a unique advantage against all side-channel attacks; however, its further performance improvement requires source preparation in the presence of noise and loss. Here, we consider the effects of photon catalysis (PC) on the DM-involved source preparation for improving the transmission distance. We address a zero-photon-catalysis (ZPC)-based source preparation for enhancing the DM–CVQKD system. The statistical fluctuation is taken into account for the practical security analysis. Numerical simulations show that the ZPC-based source preparation can not only achieve the long-distance transmission, but also contributes to the reasonable increase of the secret key rate.
Highlights
Quantum key distribution (QKD) [1,2,3,4] allows legal participants to share a secret key and enables theoretically information-secure communications [5,6,7]
A challenge is that the resulting reconciliation efficiency [14,15] is still low, which is unsuitable for long-distance transmission, whereas in the latter, one can solve this problem by using a discrete modulation (DM) source for continuous-variable quantum key distribution (CVQKD) [16], where it generates nonorthogonal coherent states, taking advantage of the randomly measured quadrature for information encoding rather than exploiting the fixed quadrature in source preparation [17]
We have suggested a ZPC-based source preparation scheme for improving the DM–CVQKD
Summary
Quantum key distribution (QKD) [1,2,3,4] allows legal participants to share a secret key and enables theoretically information-secure communications [5,6,7]. A challenge is that the resulting reconciliation efficiency [14,15] is still low, which is unsuitable for long-distance transmission, whereas in the latter, one can solve this problem by using a DM source for CVQKD [16], where it generates nonorthogonal coherent states, taking advantage of the randomly measured quadrature for information encoding rather than exploiting the fixed quadrature in source preparation [17]. As for the performance analysis of the proposed DM–CVQKD system, we take into account the asymptotic case [17] where the secure key rate can be obtained via the covariance matrix approach It is a theoretically calculated value without involving the finite-size effect.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
