Localized closed timelike curves can perfectly distinguish quantum states.
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.
Brun
Todd A
TA
Communication Sciences Institute, Department of Electrical Engineering, University of Southern California, Los Angeles, California 90089, USA.
Harrington
Jim
J
Wilde
Mark M
MM