Quantum Key Distribution Based on Private States: Unconditional Security Over Untrusted Channels With Zero Quantum Capacity

Author

Horodecki, Karol ; Horodecki, Michal ; Horodecki, Pawel ; Leung, Debbie ; Oppenheim, Jonathan

Author_Institution

Dept. of Math., Gdansk Univ., Gdansk

Volume

54

Issue

6

fYear

2008

fDate

6/1/2008 12:00:00 AM

Firstpage

2604

Lastpage

2620

Abstract

In this paper, we prove unconditional security for a quantum key distribution (QKD) protocol based on distilling pbits (twisted ebits) from an arbitrary untrusted state that is claimed to contain distillable key. Our main result is that we can verify security using only public communication-via parameter estimation of the given untrusted state. The technique applies even to bound-entangled states, thus extending QKD to the regime where the available quantum channel has zero quantum capacity. We also show how to convert our purification-based QKD schemes to prepare/measure schemes.

Keywords

channel capacity; cryptographic protocols; parameter estimation; quantum cryptography; quantum entanglement; telecommunication security; bound-entangled state; parameter estimation; quantum key distribution protocol; unconditional security; untrusted quantum channel; zero quantum capacity; Error analysis; Mathematics; Paramagnetic resonance; Parameter estimation; Phase estimation; Physics; Protocols; Quantum computing; Quantum entanglement; Security; Quantum key distribution (QKD);

fLanguage

English

Journal_Title

Information Theory, IEEE Transactions on

Publisher

ieee

ISSN

0018-9448

Type

jour

DOI

10.1109/TIT.2008.921870

Filename

4529275