Tight finite-key security for twin-field quantum key distribution

Abstract Quantum key distribution (QKD) offers a reliable solution to communication problems that require long-term data security. For its widespread use, however, the rate and reach of QKD systems must be improved. Twin-field (TF) QKD is a step forward toward this direction, with early demonstrations suggesting it can beat the current rate-versus-distance records. A recently introduced variant of TF-QKD is particularly suited for experimental implementation, and has been shown to offer a higher key rate than other variants in the asymptotic regime, where users exchange an infinite number of signals. Here, we extend the security of this protocol to the finite-key regime, showing that it can overcome the fundamental bounds on point-to-point QKD with ~1010 transmitted signals. In many practical regimes of interest, our analysis offers higher key rates than those of alternative variants. Moreover, some of the techniques we develop are applicable to the finite-key analysis of other QKD protocols.Abstract Quantum key distribution (QKD) offers a reliable solution to communication problems that require long-term data security. For its widespread use, however, the rate and reach of QKD systems must be improved. Twin-field (TF) QKD is a step forward toward this direction, with early demonstrations suggesting it can beat the current rate-versus-distance records. A recently introduced variant of TF-QKD is particularly suited for experimental implementation, and has been shown to offer a higher key rate than other variants in the asymptotic regime, where users exchange an infinite number of signals. Here, we extend the security of this protocol to the finite-key regime, showing that it can overcome the fundamental bounds on point-to-point QKD with ~1010 transmitted signals. In many practical regimes of interest, our analysis offers higher key rates than those of alternative variants. Moreover, some of the techniques we develop are applicable to the finite-key analysis of other QKD protocols.

arXiv:1910.11407npj Quantum InformationFeb 5, 202162 citations

Concise security bounds for sending-or-not-sending twin-field quantum key distribution with finite pulses

Tingting Song, Peiya Li, Jian Weng

Since its key rate can overcome the PLOB bound, sending-or-not-sending twin-field quantum key distribution (SNS-TF QKD) schemes attract more and more attention in the past three years. However, the inflection of statistical fluctuations on key rate was not considered quite comprehensively, which blocks the practical application of SNS-TF QKD. We take into account all the statistical fluctuations on probabilities, propose the finite-key analysis for SNS-TF QKD without any assumption on the type of attacks, and obtain the lower bound of key rates by applying an optimizing model. Then the finite-key rates are simulated under the reasonable values of some observed parameters, which shows that the key rates overcome the PLOB bound when the transmission distance is far from 350 km, if the number of pulses is fixed as $N={10}^{14}$ . Compared with other SNS-TF QKD schemes, we provide concise and tight finite-key bounds since the statistical fluctuations of all parameters are considered against general attacks.Since its key rate can overcome the PLOB bound, sending-or-not-sending twin-field quantum key distribution (SNS-TF QKD) schemes attract more and more attention in the past three years. However, the inflection of statistical fluctuations on key rate was not considered quite comprehensively, which blocks the practical application of SNS-TF QKD. We take into account all the statistical fluctuations on probabilities, propose the finite-key analysis for SNS-TF QKD without any assumption on the type of attacks, and obtain the lower bound of key rates by applying an optimizing model. Then the finite-key rates are simulated under the reasonable values of some observed parameters, which shows that the key rates overcome the PLOB bound when the transmission distance is far from 350 km, if the number of pulses is fixed as $N={10}^{14}$. Compared with other SNS-TF QKD schemes, we provide concise and tight finite-key bounds since the statistical fluctuations of all parameters are considered against general attacks.

Physical Review AApr 7, 20214 citations

On the security and the performance of quantum key distribution

Víctor Zapatero

Feb 11, 20220 citations

Twin-field quantum key distribution based on particle swarm optimization algorithm

Chang Liu, Yue Li, Haoyang Wang +6 more

Quantum Information ProcessingFeb 17, 20255 citations

N={10}^{14}

. Compared with other SNS-TF QKD schemes, we provide concise and tight finite-key bounds since the statistical fluctuations of all parameters are considered against general attacks.