Mode-pairing quantum key distribution based on pulse-position modulation

Bingjie Yu, Qianping Mao, Xiaomei Zhu +2 more

毛钱萍 Mao Qianping, 王乐 Wang Le, 马媛媛 MA Yuan-yuan +3 more

Yequn Zhang, Ivan B. Djordjević, Mark Allen Neifeld

Pulse-position modulation (PPM) is a promising technique that can be used to improve the efficiency of quantum key distribution (QKD) based on a Poisson photon source. In this paper, we first investigate a simple entanglement-and- PPM-based QKD protocol and demonstrate the improvement in secret key rate. However, such a PPM-based QKD protocol that utilizes only frames with a single click is still inefficient because it ignores frames with two and more clicks. For this reason we propose to use such multi-click frames to further improve the efficiency of PPM-based QKD by employing a better sifting strategy. Specifically, we focus on using the frames with two clicks in addition to those with a single click. Finally, we analyze the secret key rate under various noise levels in the scenario of high channel loss, which has been faced by most QKD applications. With the analytical results, we show the advantage of the proposed PPM-based QKD.

Lian Wang, Yuanyuan Zhou, Xuejun Zhou +2 more

Combing the orbital angular momentum and pulse position modulation, we propose a novel passive decoy-state quantum key distribution scheme with the single-intensity two-mode source. Besides, we give the lower bound of single-photon counting rate and the upper bound of single-photon error rate. Moreover, the system performance is numerically studied. The simulations demonstrate that the performance of scheme with orbital angular momentum coding is improved in terms of error rate, key generation rate and secure transmission distance. Meanwhile, by using the pulse position modulation technology, the performance is further enhanced. And the longer the frame length, the better the system performance. Therefore, our scheme does not need to modulate the light intensity, and exploits the combination of orbital angular momentum and pulse position modulation to eliminate the basis-dependent flaw and improve the key generation rate. It has certain reference value to the realization of the system.

Xingyu Zhou, Jiarui Hu, Chunhui Zhang +1 more

Yequn Zhang, Ivan B. Djordjević

In this paper, we consider quantum key distribution (QKD) using pulse-position modulation (PPM) and propose the PPM-based BB84 QKD protocol. With the adoption of PPM, the efficiency of utilizing weak laser pulses can be improved and hence the key rate. We first analyse the potential of using PPM from the perspective of raw key rate. We then provide detailed description of the proposed protocol, the encoding rule of which has to be specifically designed in order to be secure. Lastly, we consider the intercept-resend and photon-number splitting attacks and analyse the secret key rate of the proposed QKD protocol. Our analysis shows that in high-loss channel, the proposed PPM-based BB84 protocol can achieve higher secret key rates compared to the conventional BB84 protocol.