Security proof of the two-way quantum secure direct communication with channel loss and noise

Abstract

Quantum secure direct communication is one of the important mode of quantum communication, which sends secret information through a quantum channel directly without setting up a prior key. Over the past decade, numerous protocols have been proposed, and part of them have been experimentally demonstrated. However, the strict security proof is still in suspense. Two-way protocol is seen as one of the most practical protocol, in this paper, the security of the two-way quantum secure direct communication protocol will be proved against general attacks when the noisy and lossy channel is taken into account. There are two steps included in the proof, firstly, we need to prove that the mutual information between Alice and Bob is larger than the mutual information shared between Alice and the eavesdropper when the error rate in control mode is less than the predetermined threshold. Secondly, once the error rate is lower than the threshold, one can always find out a forward error correction code to guarantee the security of information transmission.

Security of quantum secure direct communication based on Wyner's wiretap channel theory

“…17 In contrast to QKD, whose security has been proven over the last two decades, [18][19][20][21][22][23][24] the security analysis of QSDC protocols has only recently debuted. 25,26 Qi et al 26 analyzed the security of DL04 QSDC protocol using Wyner's wiretap channel theory, 27 and set up a practical prototype, which can send secure messages directly at a distance of over 1.5 km with a transmission rate of 50 bps.…”

Measurement-device-independent one-step quantum secure direct communication

“…[38,39] In recent few years, QSDC has developed rapidly in both theory and experiment. [40][41][42][43][44][45][46][47][48][49][50][51][52][53][54] In theory, DI-QSDC and MDI-QSDC were put forward, which can largely enhance QSDC's security under practical experimental condition. [41][42][43][44] In 2021, Long and Zhang adopted the mask-ing technology in QSDC to increase its capacity, communication distance, and tolerable error rate greatly.…”

Faithful entanglement distribution using quantum multiplexing in noisy channel

“…-Quantum communication has attracted widespread interest for its high security during the past few decades. There are many branches of quantum communication, such as quantum key distribution (QKD) [1][2][3][4][5], quantum teleportation (QT) [6][7][8], quantum secure direct communication (QSDC) [9][10][11][12][13][14] and some other interesting protocols [15][16][17][18][19][20][21]. QKD provides an unconditionally secure method of distributing secret keys between two spatially separated parties.…”