Robustness of reference-frame-independent quantum key distribution against the relative motion of the reference frames

Abstract

Reference-Frame-Independent quantum key distribution (RFI-QKD) is known to be robust against slowly varying reference frames. However, other QKD protocols such as BB84 can also provide secrete keys if the speed of the relative motion of the reference frames is slow enough. While there has been a few studies to quantify the speed of the relative motion of the reference frames in RFI-QKD, it is not yet clear if RFI-QKD provides better performance than other QKD protocols under this condition. Here, we analyze and compare the security of RFI-QKD and BB84 protocol in the presence of the relative motion of the reference frames. In order to compare their security in real world implementation, we also consider the QKD protocols with decoy state method. Our analysis shows that RFI-QKD provides more robustness than BB84 protocol against the relative motion of the reference frames.

Satellite-mediated quantum atmospheric links

“…A similar behavior has been reported for optical signals from satellites [69,70]. On the other hand, the Rytov approximation (27) yields the divergent scintillation index for Z a →90 • and does not account for the saturation effect. The phenomenon of saturation of scintillations has been theoretically studied in Refs.…”

“…The setup of the satellite-mediated quantum links is a demanding task. The following problems must be overcome for successfully establishing a feasible quantum communication with satellites: the relative motion of the communication parties [25][26][27], the influence of gravity [28,29], the clock synchronization problem [30,31], acquisition, tracking and pointing issues with moving platforms [32][33][34], the influence of background noise [35][36][37], to name just a few. For low Earth orbiting (LEO) satellites, the communication time is limited to a few minutes [38,39] and this puts additional tight bounds on communication security.…”

Practical reference-frame-independent quantum key distribution systems against the worst relative rotation of reference frames

“…In our demonstration, we consider RFI-QKD with the slow drift of reference frames, where β can be simply deemed as constant in a short period of time. Interestingly, [22,24] assume β suffers from certain variation.…”

“…To date, there have been a lot of theoretical and experimental reports on RFI-QKD [16][17][18][19][20][21][22][23][24][25][26] due to its immunity against the slow drift of reference frames. However, the performance of practical RFI-QKD systems worsens with the increasing drift of reference frames, and their performance will become the worst when the relative rotation of reference frames reaches its maximum.…”

Reference-frame-independent, measurement-device-independent quantum key distribution using fewer quantum states

“…On the other hand, Reference-Frame-Independent QKD (RFI-QKD) is a representative QKD protocol which improves the practicality of QKD communication [15][16][17][18][19][20]. In ordinary QKD protocols, it is essential to share common reference frames between Alice and Bob.…”