Experimental measurement-device-independent quantum key distribution with uncharacterized encoding

Abstract

Measurement-device-independent quantum key distribution (MDI QKD) is an efficient way to share secrets using untrusted measurement devices. However, the assumption on the characterizations of encoding states is still necessary in this promising protocol, which may lead to unnecessary complexity and potential loopholes in realistic implementations. Here, by using the mismatched-basis statistics, we present the first proof-of-principle experiment of MDI QKD with uncharacterized encoding sources. In this demonstration, the encoded states are only required to be constrained in a two-dimensional Hilbert space, and two distant parties (Alice and Bob) are resistant to state preparation flaws even if they have no idea about the detailed information of their encoding states. The positive final secure key rates of our system exhibit the feasibility of this novel protocol, and demonstrate its value for the application of secure communication with uncharacterized devices.

Improved decoy-state quantum key distribution with uncharacterized heralded single-photon sources

“…With which the secret keys can be extracted out using uncharacterized sources by exploiting the mismatched-basis statistics which are normally discarded, and related experiments have been successfully demonstrated. [22][23][24] Based on those previous works, [21][22][23] here we present a four-intensity decoy-state proposal on quantum key distribution using uncharacterized heralded single-photon sources (HSPS). First, the four-intensity scheme with biased basis can help to improve the key rate compared with the standard three-intensity method.…”

Experimental study of secure quantum key distribution with source and detection imperfections

“…Following this line, several studies have been conducted focusing on different imperfections in the security proof, such as detection mismatch [37,38], source flaws [39][40][41][42], Trojanhorse [43], pattern effects [24], polarization-dependent loss [44], and distinguishable decoy states [45]. Experi-mental demonstrations of QKD using such refined security proofs have also been reported [46][47][48][49][50]. However, in most previous studies, the flaws were considered individually using different models.…”

Reference-frame-independent measurement-device-independent quantum key distribution with imperfect sources

“…For example, all quantum states should be prepared perfectly without flaws, while this can not be satisfactorily met with practical encoding devices, which will compromise the security of practical MDI-QKD systems. Recently, in order to relax assumptions on the encoding systems, several protocols have been proposed and demonstrated experimentally [27][28][29][30][31][32][33][34][35][36][37][38]. In particular, by exploiting the rejected-data analysis, Tamaki et al [34] proposed a loss-tolerant method to incorporate state preparation flaws in two-dimensional Hilbert space, which has been generalized to MDI-QKD [37].…”