On the optimality of individual entangling-probe attacks against BB84 quantum key distribution

I. Herbauts, S. Bettelli, H. Hübel, M. Peev

Publications: Contribution to journalArticlePeer Reviewed


It is shown that an existing method to study ideal individual attacks on the BB84 QKD protocol using error discard can be adapted to reconciliation with error correction, and that an optimal attack can be explicitly found. Moreover, this attack fills Luetkenhaus bound, independently of whether error positions are leaked to Eve, proving that it is tight. In addition, we clarify why the existence of such optimal attacks is not in contradiction with the established ``old-style'' theory of BB84 individual attacks, as incorrectly suggested recently in a news feature.
Original languageEnglish
Pages (from-to)395–406
JournalEuropean Physical Journal D
Issue number2
Publication statusPublished - Feb 2008

Austrian Fields of Science 2012

  • 103026 Quantum optics
  • 103025 Quantum mechanics
  • 103036 Theoretical physics


  • quant-ph

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