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  • Letter
  • Open Access

Phase-error-estimation security framework for quantum key distribution with correlated sources

Guillermo Currás-Lorenzo1,2,3,*, Margarida Pereira1,2,3, Kiyoshi Tamaki4, and Marcos Curty1,2,3

  • *Contact author: gcurras@vqcc.uvigo.es
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Phys. Rev. Research 8, L032045 – Published 15 September, 2026

DOI: https://doi.org/10.1103/tkx1-23xz

Abstract

Practical quantum key distribution (QKD) modulators introduce correlations between consecutively emitted pulses due to bandwidth limitations, violating key assumptions underlying many security proof techniques. Here, we address this problem by introducing a simple yet powerful mathematical framework to directly extend phase-error-estimation-based security proofs for imperfect but uncorrelated sources to also incorporate encoding correlations. Our framework overcomes important limitations of previous approaches in terms of generality and rigor, significantly narrowing the gap between theoretical security guarantees and real-world QKD implementations.

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References (43)

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Phys. Rev. Research 8, L032045– Published 15 September, 2026
  • Received 15 January 2026
  • Accepted 10 August 2026
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

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