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arXiv · 1512.05351

Two-way Gaussian quantum cryptography against coherent attacks in direct reconciliation

Carlo Ottaviani·Stefano Mancini·Stefano Pirandola
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Abstract

We consider the two-way quantum cryptographic protocol with coherent states assuming direct reconciliation. A detailed security analysis is performed considering a two-mode coherent attack, that represents the residual eavesdropping once the parties have reduced the general attack by applying symmetric random permutations. In this context we provide a general analytical expression for the keyrate, discussing the impact of the residual two-mode correlations on the security of the scheme. In particular we identify the optimal eavesdropping against two-way quantum communication, which is given by a two-mode coherent attack with symmetric and separable correlations.

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Carlo Ottaviani, Stefano Mancini, Stefano Pirandola. 2015-12-16. Two-way Gaussian quantum cryptography against coherent attacks in direct reconciliation. https://doi.org/10.1103/physreva.92.062323

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