TY  - JOUR
AU  - Pirandola, Stefano
AU  - Mancini, Stefano
AU  - Lloyd, Seth
AU  - Braunstein, Samuel L.
PY  - 2008
DA  - 2008//
TI  - Continuous-variable quantum cryptography using two-way quantum communication
T2  - Nat. Phys.
JO  - Nature Physics
SP  - 726
EP  - 730
VL  - 4
IS  - 9
KW  - fromIPMRAS
AB  - Quantum cryptography has recently been extended to continuous-variable systems, such as the bosonic modes of the electromagnetic field possessing continuous degrees of freedom. In particular, several cryptographic protocols have been proposed and experimentally implemented using bosonic modes with Gaussian statistics. These protocols have shown the possibility of reaching very high secret key rates, even in the presence of strong losses in the quantum communication channel. Despite this robustness to loss, their security can be affected by more general attacks where extra Gaussian noise is introduced by the eavesdropper. Here, we show a `hardware solution' for enhancing the security thresholds of these protocols. This is possible by extending them to two-way quantum communication where subsequent uses of the quantum channel are suitably combined. In the resulting two-way schemes, one of the honest parties assists the secret encoding of the other, with the chance of a non-trivial superadditive enhancement of the security thresholds. These results should enable the extension of quantum cryptography to more complex quantum communications.
N1  - exported from refbase (https://db.rplab.ru/refbase/show.php?record=798), last updated on Wed, 09 May 2012 11:40:21 -0500
ID  - Pirandola_etal2008
ER  -