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arxiv: 2603.16690 · v1 · submitted 2026-03-17 · 🪐 quant-ph

Secure Quantum Communication: Simulation and Analysis of Quantum Key Distribution Protocols

Mahendra Rasay , Emmanuel D. Sebastian , Subhash Prasad Sah , David Chinamerem Akah , Ajay Kumar Singh This is my paper

Pith reviewed 2026-05-15 09:47 UTC · model grok-4.3

classification 🪐 quant-ph
keywords quantum key distributionBB84B92E91Qiskit simulationquantum communicationdecoherenceeavesdropping
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The pith

Simulations of BB84, B92, and E91 protocols show QKD can generate secure keys despite noise and eavesdropping.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

This paper runs simulations of three established quantum key distribution protocols inside the Qiskit framework to test their behavior under realistic channel conditions. It incorporates noise, decoherence, and eavesdropping to track error rates, secret-key output, and overall security. The results indicate that usable secret keys can still be extracted after error correction and privacy amplification. Practical limits from hardware imperfections and channel losses are identified as the main barriers to wider use. The work concludes that these protocols remain viable for secure communication once quantum computers threaten classical methods.

Core claim

The simulations of the BB84, B92, and E91 protocols demonstrate that quantum key distribution can achieve information-theoretic security even in the presence of noise, decoherence, and eavesdropping, thereby establishing the practical feasibility of QKD for secure communication in the quantum era.

What carries the argument

Qiskit-based simulation of BB84, B92, and E91 circuits that injects noise and decoherence models to compute quantum bit error rates and extract secret key rates after post-processing.

Load-bearing premise

The Qiskit noise and decoherence models accurately represent the dominant error sources in real quantum channels and hardware.

What would settle it

A laboratory implementation of any one of the three protocols on actual quantum hardware that produces error rates high enough to drive the secret key rate to zero would falsify the feasibility conclusion.

Figures

Figures reproduced from arXiv: 2603.16690 by Ajay Kumar Singh, David Chinamerem Akah, Emmanuel D. Sebastian, Mahendra Rasay, Subhash Prasad Sah.

Figure 2
Figure 2. Figure 2: Bloch sphere representation of the computational basis state [PITH_FULL_IMAGE:figures/full_fig_p004_2.png] view at source ↗
Figure 1
Figure 1. Figure 1: Bloch sphere representation of the computational basis state [PITH_FULL_IMAGE:figures/full_fig_p004_1.png] view at source ↗
Figure 6
Figure 6. Figure 6: Three-dimensional Bloch sphere representation of measurement directions [PITH_FULL_IMAGE:figures/full_fig_p005_6.png] view at source ↗
Figure 5
Figure 5. Figure 5: Two-dimensional representation of polarization measurement angles [PITH_FULL_IMAGE:figures/full_fig_p005_5.png] view at source ↗
Figure 11
Figure 11. Figure 11: Relationship between Attack and QBER [PITH_FULL_IMAGE:figures/full_fig_p013_11.png] view at source ↗
Figure 12
Figure 12. Figure 12: QBER heatmap for BB84 Protocol [PITH_FULL_IMAGE:figures/full_fig_p013_12.png] view at source ↗
Figure 10
Figure 10. Figure 10: Relationship between Noise and QBER [PITH_FULL_IMAGE:figures/full_fig_p013_10.png] view at source ↗
Figure 13
Figure 13. Figure 13: QBER as a function of channel noise in the E91 protocol with [PITH_FULL_IMAGE:figures/full_fig_p014_13.png] view at source ↗
Figure 14
Figure 14. Figure 14: CHSH Bell parameter as a function of channel noise in the [PITH_FULL_IMAGE:figures/full_fig_p014_14.png] view at source ↗
Figure 18
Figure 18. Figure 18: Increasing channel noise under combined Bell and k [PITH_FULL_IMAGE:figures/full_fig_p015_18.png] view at source ↗
Figure 17
Figure 17. Figure 17: Effect of combined key and Bell eavesdropping on CHSH parameter and QBER in the E91 protocol [PITH_FULL_IMAGE:figures/full_fig_p015_17.png] view at source ↗
read the original abstract

Quantum computing poses significant threats to conventional cryptographic techniques such as RSA and AES, motivating the need for quantum secure communication methods. Quantum Key Distribution (QKD) offers information theoretic security based on fundamental quantum principles. This paper presents a simulation-based analysis of well-known QKD protocols, namely BB84, B92, and E91, using the IBM Qiskit framework. Realistic quantum channel effects, including noise, decoherence, and eavesdropping, are modeled to evaluate protocol performance. Key metrics such as error rate, secret key generation, and security characteristics are analyzed and compared. The study highlights practical challenges in QKD implementation, including hardware limitations and channel losses, and discusses insights toward scalable and robust quantum communication systems. The results support the feasibility of QKD as a promising solution for secure communication in the quantum era.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 2 minor

Summary. The manuscript simulates the BB84, B92, and E91 QKD protocols in Qiskit, incorporating models for noise, decoherence, and eavesdropping. It evaluates performance via error rates, secret-key lengths, and security metrics, concluding that the results support the feasibility of QKD for secure communication despite hardware limitations and channel losses.

Significance. If the Qiskit noise models were shown to match dominant experimental error sources, the comparative protocol analysis would offer practical guidance on relative robustness under realistic conditions. As presented, the work remains an uncalibrated illustration whose quantitative outputs cannot be directly compared to laboratory benchmarks.

major comments (2)
  1. [Results] Results section (and abstract): no error bars, confidence intervals, or number of Monte Carlo shots are reported for the simulated error rates and key lengths, so the claimed support for feasibility rests on point estimates whose statistical reliability cannot be assessed.
  2. [Methods] Simulation setup / Methods: the specific values chosen for depolarizing probability, amplitude-damping time, phase-damping time, and detector dark-count rates are not stated, nor are they calibrated against published experimental QKD data or hardware specifications, leaving the central feasibility claim dependent on unverified modeling assumptions.
minor comments (2)
  1. [Abstract] The abstract states that 'realistic quantum channel effects' are modeled but does not list the concrete Qiskit noise channels or parameter values used; this should be added for reproducibility.
  2. [Figures] Figure captions and axis labels should explicitly indicate whether plotted quantities are averaged over multiple runs and what the simulation shot count was.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for the constructive comments. We have revised the manuscript to address the statistical reporting of simulation results and the explicit specification of noise parameters, while noting the illustrative nature of the modeling.

read point-by-point responses

  1. Referee: [Results] Results section (and abstract): no error bars, confidence intervals, or number of Monte Carlo shots are reported for the simulated error rates and key lengths, so the claimed support for feasibility rests on point estimates whose statistical reliability cannot be assessed.

    Authors: We agree that the absence of error bars and shot counts limits the ability to assess statistical reliability. In the revised manuscript we now report 1024 shots per simulation run, include standard-deviation error bars computed over 20 independent Monte Carlo repetitions, and add binomial confidence intervals for the error-rate estimates. These changes allow quantitative evaluation of the reported metrics and support the feasibility conclusions with greater transparency. revision: yes

  2. Referee: [Methods] Simulation setup / Methods: the specific values chosen for depolarizing probability, amplitude-damping time, phase-damping time, and detector dark-count rates are not stated, nor are they calibrated against published experimental QKD data or hardware specifications, leaving the central feasibility claim dependent on unverified modeling assumptions.

    Authors: We acknowledge that the exact numerical values were omitted from the original text. The revised Methods section now lists the parameters explicitly (depolarizing probability 0.05, T1 = 50 μs, T2 = 30 μs, dark-count rate 10^{-6} per gate). These values are representative of typical superconducting-qubit and fiber-channel data in the literature; we have added a brief sensitivity analysis and references to experimental benchmarks. A full hardware-specific calibration lies outside the scope of this general simulation study, so the revision is partial on that aspect. revision: partial

Circularity Check

0 steps flagged

No circularity in forward simulation of QKD protocols

full rationale

The manuscript performs numerical simulations of BB84, B92, and E91 using Qiskit noise models for channel effects. No equations, derivations, or predictions are presented that reduce by construction to fitted inputs or self-citations. Results are generated directly from the chosen models and parameters; the feasibility conclusion is an interpretive summary of those outputs rather than a tautological result. This matches the default expectation for simulation studies that remain self-contained against external benchmarks.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 0 invented entities

The central claim rests on the assumption that standard Qiskit channel models capture the dominant physical effects; no new free parameters, axioms, or invented entities are introduced beyond those already present in the Qiskit library and textbook QKD security arguments.

axioms (1)
  • standard math Quantum mechanics guarantees that any eavesdropping on single photons or entangled pairs introduces detectable errors (no-cloning and measurement disturbance).
    Invoked implicitly when the paper states that security is information-theoretic and based on fundamental quantum principles.

pith-pipeline@v0.9.0 · 5449 in / 1329 out tokens · 53893 ms · 2026-05-15T09:47:34.364692+00:00 · methodology

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Reference graph

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