Abstract
Odd-parity error rejection (OPER), in particular the method of actively odd parity pairing (AOPP), can drastically improve the asymptotic key rate of sending-or-not-sending twin-field (SNS-TF) quantum key distribution (QKD). However, in practice, the finite-key effects have to be considered for the security. Here, we propose a zigzag approach to verify the phase-flip error of the survived bits after OPER or AOPP. Based on this, we can take all the finite-key effects efficiently in calculating the non-asymptotic key rate. Numerical simulation shows that our approach here produces the highest key rate over all distances among all existing methods, improving the key rate by more than 100% to 3000% in comparison with different prior art methods with typical experimental setting. These verify the advantages of the AOPP method with finite data size. Also, with our zigzag approach here, the non-asymptotic key rate of SNS-TF QKD can by far break the absolute bound of repeater-less key rate with whatever detection efficiency. We can even reach a non-asymptotic key rate more than 40 times of the practical bound and 13 times of the absolute bound with 1012 pulses.
Highlights
Quantum key distribution (QKD)[1,2,3,4,5,6,7,8] can provide secure private communication between two remote parties Alice and Bob
The decoy-state method [32,33,34] can assure the security of the QKD protocol with imperfect sources and maintain the high key rate, and attracts many studies on both theories [35,36,37,38,39,40,41] and experiments [42,43,44,45,46,47,48,49,50,51,52]
We study the the finite key effects for the SNS protocol with odd-parity error rejection (OPER)
Summary
Quantum key distribution (QKD)[1,2,3,4,5,6,7,8] can provide secure private communication between two remote parties Alice and Bob. The two-way communication method, with odd-parity error rejection (OPER) can be applied to SNS protocol and increases the probability of sending the signal coherent state [20]. This method can improve the asymptotic key rate and secure distance of SNS protocol drastically. We have shown by de Finetti theorem that after error rejection, the phase-flip error rate of survived untagged bits from odd-parity groups can never be larger than those from even-parity groups, in the limit of infinite number of raw pairs initially [20]. The details of some calculations are shown in the appendix
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
