title: Localized closed timelike curves can perfectly distinguish quantum states.
abstract: We show that qubits traveling along closed timelike curves are a resource that a party can exploit to distinguish perfectly any set of quantum states. As a result, an adversary with access to closed timelike curves can break any prepare-and-measure quantum key distribution protocol. Our result also implies that a party with access to closed timelike curves can violate the Holevo bound.
authors.affiliation: Communication Sciences Institute, Department of Electrical Engineering, University of Southern California, Los Angeles, California 90089, USA.
authors.forename: Todd A
authors.initials: TA
authors.lastname: Brun
authors.forename: Jim
authors.initials: J
authors.lastname: Harrington
authors.forename: Mark M
authors.initials: MM
authors.lastname: Wilde