In this paper, we investigate the impact of classical optical communications in quantum key distribution (QKD) over hollow-core fiber (HCF), multi-core (MCF) and single-core (SCF) propose wavelength allocation schemes to enhance QKD performance. Firstly, theoretically analyze noise interference HCF, MCF SCF, such as spontaneous Raman scattering (SpRS) four-wave mixing (FWM). To mitigate these types optimize performance, a joint suppression (JSWA) scheme. FWM are also proposed for comparison....

Quantum digital signatures (QDSs), which are unforgeable, non-repudiable, and transferable, widely used in quantum communication networks. Unfortunately, previous protocols have often relied on three-party models for security analysis experimental verification. As the number of parties increases, links required increases exponentially, undoubtedly leading to high channel losses cost multi-party QDSs. This study proposes a ring QDS scheme that can effectively deal with issue redundant links....

Abstract Mode pairing quantum key distribution (MP-QKD) overcomes the repeaterless bound without requiring phase locking and tracking. However, MP-QKD still assumes that light source is trusted, which can present challenges in practical deployments potentially introduce security vulnerabilities. In this paper, we propose a monitoring (LSM) scheme guarantees of with untrusted sources. The simulation results demonstrate that, when considering sources, performance LSM remains nearly identical...

Quantum key distribution (QKD) generates information-theoretical secret keys between two parties based on the physical laws of quantum mechanics. Following advancement in communication networks, it becomes feasible and economical to combine QKD with classical optical through same fiber using dense wavelength division multiplexing (DWDM) technology. This study proposes a detailed scheme TF-QKD protocol DWDM technology analyzes its performance, considering influence channel number adjacent...

The source flaw associated with the basis vector in reference-frame-independent measurement-device-independent quantum key distribution (RFI-MDI-QKD) has not been systematically studied. As a result, it is often assumed that bit error equal to phase error, which theoretically rigorous. Here, we propose postprocessing method estimate rate from discarded mismatched-basis statistics, where qubit does need be characterized detail. of RFI-MDI-QKD protocol can thus corrected using this method....

Reference-frame-independent quantum key distribution (RFI-QKD) can allow a system to obtain the ideal rate and transmission distance without reference calibration, which has attracted much attention. Here, we propose an RFI-QKD protocol based on wavelength division multiplexing (WDM) considering finite-key analysis crosstalk. The bound for with decoy states is derived under crosstalk of WDM. resulting secret RFI-QKD, more rigorous, obtained. Simulation results reveal that WDM affected by...

Reference frame independent and measurement device quantum key distribution (RFI-MDI-QKD) has the advantages of being immune to detector side loopholes misalignment reference frame. However, several former related research works are based on unrealistic assumption perfect source preparation. In this paper, we merge a loss-tolerant method into RFI-MDI-QKD consider flaws rate estimation compare it with coin method. Based reliable experimental scheme, joint influence both is discussed...

In this paper, we proposed the scheme for a passive round-robin differential-phase-shift quantum key distribution (RRDPS-QKD) set-up based on principle of Hong–Ou–Mandel interference. Our requires two legitimate parties to prepare their signal state with different non-orthogonal bases instead single in original protocol. Incorporating characteristic, establish level security our protocol under intercept-resend attack and demonstrate its detector-flaw-immune feature. Furthermore, show that...

This study investigate the integration of discrete modulated coherent state (DMCS) continuous variable quantum key distribution (CV-QKD) with wavelength division multiplexing (WDM) in 5G fronthaul optical networks. Firstly, an architecture quantum-classical co-propagation C-band DWDM-based fornthaul network is constructed and assignment scheme for classical/quantum channels designed. By assigning band low Raman scattering coefficient setting channel space to be 200 GHz, proposed can...

Integrating quantum key distribution (QKD) with classical optical communication is a deployment-friendly and cost-effective approach to advancing QKD network implementation. However, the noise introduced by intense signals into channel severely impacts performance of system, presenting challenges for long-distance coexistence transmission. In this paper, we successfully demonstrate simultaneous propagation transport (OTN) in C-band over distances exceeding 100 km. We establish transmission...

Heterogeneous multicore fibers (Hetero-MCFs) offer relatively lower inter-core crosstalk (XT) and improved bend resistance, making them feasible for the coexistence of quantum key distribution (QKD) classical communications. However, detailed analyses their impact on QKD performance remain limited. This study comprehensively investigates significant effects core layouts XT in Hetero-MCFs under varying service demands theory. When allocating cores based maximum levels, hexagonal perform worst...

The mode-pairing quantum key distribution (MP-QKD) protocol, which can achieve high rates over long distances without phase locking, is a potential candidate for implementing intercity QKD. However, achieving precise control of the light source intensity in field MP-QKD experiment an exceedingly challenging task. In this Letter, we study decoy-state protocol with fluctuations. Furthermore, propose statistical analysis method based on T-distribution to calculate confidence intervals Finally,...

The mode pairing quantum key distribution (MP-QKD) protocol has attracted considerable attention for its capability to ensure high secure rates over long distances without requiring global phase locking. However, ensuring symmetric channels the MP-QKD is challenging in practical communication networks. Previous studies on asymmetric have relied ideal decoy state assumptions and infinite-key analysis, which are unattainable real-world deployment. In this paper, we conduct a security analysis...

A few-mode erbium-doped fiber (FM-EDF) with a step refractive index and trench structure is designed proposed to realize the modal gain equalization of amplifier (FM-EDFA). The layered-doping technology used reduce mode difference (DMG). doping radius concentration are adjusted obtain optimum FM-EDF structure. When applied FM-EDFA, DMG whole C-band less than 0.15 dB 0.12 at 1550 nm. minimum (Δneff) between modes can be calculated according core; i.e., 1.35×10-3, which will greatly coupling...

Quantum key distribution (QKD) generates information-theoretical secure keys between two parties based on the physical laws of quantum mechanics. The phase-matching (PM) QKD protocol allows rate to break channel secret capacity limit without repeaters, and security is demonstrated by using equivalent entanglement. In this paper, wavelength division multiplexing (WDM) technique applied PM-QKD considering effect crosstalk noise rate. performance WDM with influence adjacent classical channels...

We propose a fully symmetrical QKD system that enables quantum states to be prepared and measured simultaneously without compromising performance. Over 25.6 km fiber channel, we demonstrate point-to-point operations with asymmetric Mach–Zehnder interferometer modules. Two interference visibilities of above 99% indicate the proposed has excellent stability. Consequently, scheme not only improves feasibility distributing secret keys, but also closer more practical applications.

During free-space quantum key distribution, the rotation and fluctuation of reference frame degrades performance distribution (QKD). Reference-frame-independent QKD (RFI-QKD) overcomes this issue effectively. To date, much theoretical experimental research has been conducted on RFI-QKD. However, these studies are all based air satellite ground, none have investigated RFI-QKD in an underwater channel. Therefore, paper constructed a channel model that considered both scattering optical...

Future quantum communication networks envisaged on a global scale will include various interlinked via optical fiber and free space channels. In recent years, key distribution (QKD) protocol based has been extensively studied. Twin-field QKD (TF-QKD) may enable 550 km using standard without repeaters. However, the performance of TF-QKD in free-space channel is still unclear. this paper, model proposed with specific turbulence characterization discussed. Here, rate under multiple scenarios...

Quantum communication plays an important role in quantum information science due to its unconditional security. In practical implementations, the users of each vary with transmitted information, and hence not all are required participate round. Therefore, improving flexibility efficiency actual process is highly demanded. Here, we propose a theoretical scheme that realizes secret key distribution for both two-party (QKD) multi-party sharing (QSS) modes. The sender, Alice, can freely select...

We present a novel Z-trench-assisted (Z-TA) graded index 9-LP-mode fiber that significantly suppresses the maximum absolute differential modal group delay (Max |DMGD|) while obtaining high normalized spatial density (NSD). The finite element method (FEM) is applied for numerical simulations, and results show Max |DMGD| 18.9 ps/km at 1550 nm. To best of our knowledge, it improved by more than 30% compared to theoretical optimal value in TA structure so far. Furthermore, NSD proposed can reach...

The integration of quantum key distribution (QKD) and classical optical communication has attracted widespread attention. In this Letter, we experimentally demonstrate a real-time co-propagation 1 Tbps for 10 channels with one discrete-variable QKD channel in the weakly coupled few-mode fiber (FMF). Based on selection optimal device parameters wavelength assignment channels, as well optimization equipment performance, secure rate high 2.7 kbps coexistence transmission can be achieved using...