{
  "abstract": "Quantum conference key agreement (QCKA) enables multiple spatially separated users to establish a common key with composable information-theoretic security by exploiting multipartite quantum correlations. Greenberger--Horne--Zeilinger (GHZ) states are a natural resource for this task, but their distribution over optical fiber is degraded by transmission loss, polarization decoherence, and detector imperfections. We investigate the finite-key performance of an $N$-party GHZ-based QCKA system using the $N$-BB84 protocol, where each optical link is modeled by extending the bipartite erasure--Pauli channel to incorporate detector dark counts. We characterize the impact of this quantum channel on the shared GHZ state and derive closed-form expressions for the error rates. The analytical results reveal that the local bit-error rate depends only on transmissivity and dark counts, while the global phase-error rate compounds over all $N-1$ links and therefore degrades faster with both distance and the number of parties. These error rates are integrated into a finite-key secret-key-rate (SKR) framework, in which we optimize the parameter-estimation probability via Brent's derivative-free method. Numerical results show that increasing fiber distance and network size reduce the achievable SKR. Furthermore, the optimized parameter-estimation probability consistently increases the SKR and extends the maximum secure distance relative to a fixed-allocation baseline, with comparison to the asymptotic limit quantifying the residual finite-key penalty.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.05448",
  "author_total": 3,
  "authors": [
    {
      "name": "Dipanjan Bera"
    },
    {
      "name": "Ramniwas Meena"
    },
    {
      "name": "Neel Kanth Kundu"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/6qwqsaxafef5j.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.05448",
  "fulltext_url": null,
  "id": "6qwqsaxafef5j",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.05448",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "eess.SP"
    ],
    [
      "arxiv",
      "quant-ph"
    ],
    [
      "openalex",
      "1702|Quantum Information and Cryptography"
    ]
  ],
  "openalex": "W7220685610",
  "pdf_url": "https://arxiv.org/pdf/2610.05448",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-04",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/6qwqsaxafef5j.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:27:01Z",
      "native_id": "2610.05448",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.05448"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:quant-ph",
      "subfield": "quantum"
    }
  ],
  "title": "Performance Analysis of Multiparty GHZ-State Quantum Conference Key Agreement over Optical Fiber Channel",
  "title_text": "Performance Analysis of Multiparty GHZ-State Quantum Conference Key Agreement over Optical Fiber Channel",
  "type": "preprint",
  "updated_at": "2026-10-30T12:27:01Z",
  "url": "https://research.draconitic.com/paper/6qwqsaxafef5j",
  "venue": "arXiv",
  "versions": []
}