title: Quantum key distillation from Gaussian states by Gaussian operations.
abstract: We study the secrecy properties of Gaussian states under Gaussian operations. Although such operations are useless for quantum distillation, we prove that it is possible to distill a secret key secure against any attack from sufficiently entangled Gaussian states with nonpositive partial transposition. Moreover, all such states allow for key distillation, when Eve is assumed to perform finite-size coherent attacks before the reconciliation process.
authors.affiliation: ICFO-Institut de Ciéncies Fotòniques, Jordi Girona 29, Edifici Nexus II, E-08034 Barcelona, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Navascués
authors.forename: J
authors.initials: J
authors.lastname: Bae
authors.forename: J I
authors.initials: JI
authors.lastname: Cirac
authors.forename: M
authors.initials: M
authors.lastname: Lewestein
authors.forename: A
authors.initials: A
authors.lastname: Sanpera
authors.forename: A
authors.initials: A
authors.lastname: Acín