Comment on: "Exposed-key weakness of αη" [Phys. Lett. A 370 (2007) 131]

Ranjith Nair*, Horace P. Yuen

*Corresponding author for this work

Research output: Contribution to journalComment/debatepeer-review

8 Scopus citations


We show that the insecurity claim of the αη cryptosystem made by C. Ahn and K. Birnbaum in [C. Ahn, K. Birnbaum, Phys. Lett. A 370 (2007) 131] under heterodyne attack is based on invalid extrapolations of Shannon's random cipher analysis and on an invalid statistical independence assumption. We show, both for standard ciphers and αη, that expressions of the kind given by Ahn and Birnbaum can at best be interpreted as security lower bounds.

Original languageEnglish (US)
Pages (from-to)7091-7096
Number of pages6
JournalPhysics Letters, Section A: General, Atomic and Solid State Physics
Issue number47
StatePublished - Nov 24 2008


  • Data encryption
  • Quantum cryptography
  • Random cipher

ASJC Scopus subject areas

  • Physics and Astronomy(all)


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