非對稱雙場量子密鑰分發協議之研究

近年來，一種全新的量子密鑰分發協議雙場量子協議被提出，有別於MDI-QKD需要兩個光子同時抵達第三方進行雙光子干涉量測，雙場量子密鑰協議只需一個光子抵達第三方進行干涉，進而使其密鑰生成距離大大地增加200km，在雙場量子密鑰提出後不久，根據其衍生來的各式協議相繼被提出，這些被提出的協議中根據其性質主要可以被歸類為兩類，一是PM-QKD，另一個SNS TF-QKD協議，在這篇論文中，我們主要探討在2018年由Xiongfeng Ma等人提出的PM-QKD和SNS TF-QKD在非對稱的情況下，並比較其密鑰生成率，進一步與對稱情況下的PM-QKD以及SNS TF-QKD和傳統BB84協議進行比較，其結果顯示在非對稱的情形下，即Alice和Charlie之間的量子通道距離大於Bob和Charlie時，PM和SNS的密鑰生成率用非對稱的協議方法比用對稱協議的方法還要好，且非對稱的PM其密鑰可傳輸距離比SNS還要遠，最後，在與傳統BB84協議比較的結果顯示，兩者在傳輸距離及密鑰生成率皆有顯著的提升。

關鍵字

量子密鑰

並列摘要

Recently the new protocol twin-field quantum key distribution has been proposed. Due to its single-photon interference, the key generation has been dramatically improved by about 200km with respect to MDI-QKD, which is mainly dependent on two-photon interference. After the protocol being proposed, several variable types of TF-QKD has been proposed these recent decades. Among those variant protocols, there is two major types. One is phase-matching and the other is sending or not sending type. In this paper, we mainly discuss both types of TF-QKD in the asymmetric, and compare their key generation rate with each other and with the symmetry PM、SNS protocol and the traditional quantum key distribution protocol BB84. The outcome shows that in asymmetric condition, the distance between Alice and Charlie is longer than the distance between Bob and Charlie, asymmetric SNS、PM protocols’ key generation rate both better than symmetric ones. Furthermore PM asymmetric protocol key can transmit longer distances than SNS asymmetric one. In the end, we can see that both asymmetric PM and SNS protocols’ key generation are much better than traditional quantum key distribution protocol BB84.

並列關鍵字

quantum key distribution

參考文獻

[1] Bennett C H, Brassard G. Quantum cryptography: public key distribution and coin tossing//Proceedings of the IEEE International Conference on Computers, Systems, and Signal Processing (IEEE, New York), 1984, 175