Provable entanglement and information cost for qubit-based quantum key-distribution protocols
Institut für Angewandte Physik, Technische Universität Darmstadt, 64289 Darmstadt, Germany
Corresponding author: a firstname.lastname@example.org
Published online: 22 November 2005
Provable entanglement has been shown to be a necessary precondition for unconditionally secure key generation in the context of quantum cryptographic protocols. We estimate the maximal threshold disturbance up to which the two legitimate users can prove the presence of quantum correlations in their data, in the context of the four- and six-state quantum key-distribution protocols, under the assumption of coherent attacks. Moreover, we investigate the conditions under which an eavesdropper can saturate these bounds, by means of incoherent and two-qubit coherent attacks. A direct connection between entanglement distillation and classical advantage distillation is also presented.
PACS: 03.67.Dd – Quantum cryptography / 03.67.Hk – Quantum communication
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2005