This paper proposes a new semi‐quantum key distribution protocol, allowing two “classical” participants without sophisticated quantum capability to establish a shared secret key under an untrusted ...third party (a quantum server). The proposed protocol is free from several well‐known attacks. Furthermore, the efficiency is better than the existing three‐party SQKD protocol in which the classical participants must have the quantum measurement capability.
Liu and Hwang propose a new semi‐quantum key distribution (SQKD) protocol, allowing two “classical” participants without sophisticated quantum capability to establish a shared secret key under an untrusted third party (a quantum server). The proposed protocol is free from several well‐known attacks. Furthermore, the efficiency is better than the existing three‐party SQKD protocol in which the classical participants must have the quantum measurement capability.
Quantum key distribution (QKD) constitutes a symmetric secret key negotiation protocol capable of maintaining information-theoretic security. Given the recent advances in QKD networks, they have ...evolved from academic research to some preliminary applications. A QKD network consists of two or more QKD nodes interconnected by optical fiber or free space links. The secret keys are negotiated between any pair of QKD nodes, and then they can be delivered to multiple users in various areas for ensuring long-term protection and forward secrecy. We commence by introducing the QKD basics, followed by reviewing the development of QKD networks and their implementation in practice. Subsequently, we describe the general QKD network architecture, its elements, as well as its interfaces and protocols. Next, we provide an in-depth overview of the associated physical layer and network layer solutions, followed by the standardization efforts as well as the application scenarios associated with QKD networks. Finally, we discuss the potential future research directions and provide design guidelines for QKD networks.
The establishment of a world-wide quantum communication network relies on the synergistic integration of satellite-based links and fiber-based networks. The first are helpful for long-distance ...communication, as the photon losses introduced by the optical fibers are too detrimental for lengths greater than about 200 km. This work aims at giving, on the one hand, a comprehensive and fundamental model for the losses suffered by the quantum signals during the propagation along an atmospheric free-space link. On the other hand, a performance analysis of different quantum key distribution (QKD) implementations is performed, including finite-key effects, focusing on different interesting practical scenarios. The specific approach that we chose allows to precisely model the contribution due to different weather conditions, paving the way towards more accurate feasibility studies of satellite-based QKD missions.
In recent years, there has been a great effort to prove the security of quantum key distribution (QKD) with a minimum number of assumptions. Besides its intrinsic theoretical interest, this would ...allow for larger tolerance against device imperfections in the actual implementations. However, even in this device-independent scenario, one assumption seems unavoidable, that is, the presence of a protected space devoid of any unwanted information leakage in which the legitimate parties can privately generate, process and store their classical data. In this paper we relax this unrealistic and hardly feasible assumption and introduce a general formalism to tackle the information leakage problem in most of existing QKD systems. More specifically, we prove the security of optical QKD systems using phase and intensity modulators in their transmitters, which leak the setting information in an arbitrary manner. We apply our security proof to cases of practical interest and show key rates similar to those obtained in a perfectly shielded environment. Our work constitutes a fundamental step forward in guaranteeing implementation security of quantum communication systems.
In this paper, we introduce intrinsic non-locality and quantum intrinsic non-locality as quantifiers for Bell non-locality, and we prove that they satisfy certain desirable properties such as ...faithfulness, convexity, and monotonicity under local operations and shared randomness. We then prove that intrinsic non-locality is an upper bound on the secret-key-agreement capacity of any device-independent protocol conducted using a device characterized by a correlation p, while quantum intrinsic non-locality is an upper bound on the same capacity for a correlation arising from an underlying quantum model. We also prove that intrinsic steerability is faithful, and it is an upper bound on the secret-key-agreement capacity of any one-sided-device-independent protocol conducted using a device characterized by an assemblage ˆ . Finally, we prove that quantum intrinsic non-locality is bounded from above by intrinsic steerability.
Key distribution techniques are indispensable for maintaining privacy, preventing unauthorized access, and safeguarding sensitive data in consumer electronics networks. Several recent research works ...focused on developing conventional key distribution protocols for consumer electronics networks. However, conventional key distribution algorithms face several limitations in consumer electronic networks, like key management complexity, key storage issues, and cost and resource constraints with increasing consumer electronic devices. Quantum Key Distribution (QKD) techniques overcome the limitations of conventional key distribution techniques and have several advantages, such as eavesdropping detection, intercept-resend attack resilience, trusted party independence, etc. Despite such advantages, no research has explored the potential of QKD techniques in consumer electronics networks. Addressing this research gap, in this work, we conduct a comparative analysis between QKD techniques like BB84, BB92, and E91 and conventional key distribution techniques with a broad evaluation framework that includes metrics including key generation rate, error rate, security level, and time complexity. We have also analyzed the QKD algorithms regarding several resource usage parameters like CPU, memory, disk space, and network usage. We also examine the principles, advantages, limitations, and applicability of securing web transactions in consumer electronics networks.
The application of semi‐quantum conception can provide unconditional secure communication for communicators without quantum capabilities. A semi‐quantum key distribution (SQKD) protocol based on ...four‐particle cluster states is put forward, which can achieve key distribution among one quantum party and two classical parties simultaneously. Furthermore, this protocol can be expanded to the χ‐party (χ>3) communication scheme. Compared with the existing multi‐party SQKD protocol, the proposed protocol and the extended one own more excellent time efficiency and qubit efficiency. The security of the proposed SQKD protocol under ideal circumstances is validated while the key rate under non‐ideal conditions is calculated.
The proposed semi‐quantum key distribution protocol with four‐particle cluster states can achieve key distribution among one quantum party and two classical parties simultaneously, which can be expanded to more than two classical communication parties. The proposed protocol owns great time efficiency and qubit efficiency, whose security under ideal circumstances and key rate under non‐ideal conditions are analyzed.
Mediated semi-quantum key distribution (MSQKD) allows two “classical” participants to establish a secret key with the help of an untrusted quantum third party (TP). In all existing MSQKD protocols, ...the quantum capability required by TP is high and thus it needs much cost in a real implementation. In this paper, we propose an efficient MSQKD protocol, where TP only needs to prepare and measure qubits in the X basis and two “classical” participants just have the ability to prepare and measure qubits in the Z basis. Compared with other similar MSQKD protocols, the proposed protocol reduces the capability requirements of TP without sacrificing the qubit efficiency.
•An efficient mediated semi-quantum key distribution protocol is proposed.•The quantum capability required by TP is reduced.•TP only needs to prepare and measure qubits in the X basis.
Twin-field (TF) quantum key distribution (QKD) represents a novel QKD approach whose principal merit is to beat the point-to-point private capacity of a lossy quantum channel, thanks to performing ...single-photon interference in an untrusted node. Indeed, recent security proofs of various TF-QKD type protocols have confirmed that the secret key rate of these schemes scales essentially as the square root of the transmittance of the channel. Here, we focus on the TF-QKD protocol introduced by Curty et al, whose secret key rate is nearly an order of magnitude higher than previous solutions. Its security relies on the estimation of the detection probabilities associated to various photon-number states through the decoy-state method. We derive analytical bounds on these quantities assuming that each party uses either two, three or four decoy intensity settings, and we investigate the protocol's performance in this scenario. Our simulations show that two decoy intensity settings are enough to beat the point-to-point private capacity of the channel, and that the use of four decoys is already basically optimal, in the sense that it almost reproduces the ideal scenario of infinite decoys. We also observe that the protocol seems to be quite robust against intensity fluctuations of the optical pulses prepared by the parties.
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