par Grosshans, F.;Acín, Antonio;Cerf, Nicolas 
Editeur scientifique Cerf, Nicolas;Leuchs, Gerd;Polzik, E. S.
Référence Quantum information with Continuous Variables of Atoms and Light, Imperial College Press, London, page (63-83)
Publication Publié, 2007
Editeur scientifique Cerf, Nicolas
;Leuchs, Gerd;Polzik, E. S.Référence Quantum information with Continuous Variables of Atoms and Light, Imperial College Press, London, page (63-83)
Publication Publié, 2007
Partie d'ouvrage collectif
| Résumé : | Quantum key distribution is a technique in which secret key bits are encoded into quantum states, which are transmitted over a quantum channel (e.g., an optical link) so that the security is guaranteed by the laws of quantum physics. Most experimental realizations to date have relied on discrete protocols, involving ideally single-photons states (or, in practice, strongly attenuated light pulses) as well as single-photon detectors. In this chapter, we present an overview of the recent continuous-variable quantum cryptosystems, which rely on continuously-modulated Gaussian states (e.g., coherent states) and homodyne (or heterodyne) detection. The series of security proofs of these protocols against increasingly powerful attacks will be reviewed. A particular emphasis will be put on the optimality of Gaussian attacks in this context, which holds provided that the second-order moments of the relevant variables are monitored. |
