Experimental implementation of non-Gaussian attacks on a continuous-variable quantum key distribution system

Jérôme Lodewyck (1, 2) , Thierry Debuisschert (1) , Raul Garcia-Patron (3) , Rosa Tualle-Brouri (2) , Nicolas J. Cerf (3) , Philippe Grangier (2)

1 Thales Research and Technology [Palaiseau]
2 Laboratoire Charles Fabry de l'Institut d'Optique / Optique quantique
3 ULB - Université libre de Bruxelles

An intercept-resend attack on a continuous-variable quantum-key-distribution protocol is investigated experimentally. By varying the interception fraction, one can implement a family of attacks where the eavesdropper totally controls the channel parameters. In general, such attacks add excess noise in the channel, and may also result in non-Gaussian output distributions. We implement and characterize the measurements needed to detect these attacks, and evaluate experimentally the information rates available to the legitimate users and the eavesdropper. The results are consistent with the optimality of Gaussian attacks resulting from the security proofs.

Domaines: Physique Quantique [quant-ph]

Jérôme Lodewyck, Thierry Debuisschert, Raul Garcia-Patron, Rosa Tualle-Brouri, Nicolas J. Cerf, et al.. Experimental implementation of non-Gaussian attacks on a continuous-variable quantum key distribution system. Physical Review Letters, 2007, 98, pp.030503. ⟨10.1103/PhysRevLett.98.030503⟩. ⟨hal-00509168⟩