Simple security proof of quantum key distribution via uncertainty principle

TL;DR

This paper introduces a straightforward security proof for quantum key distribution protocols using the uncertainty principle, simplifying previous methods and accommodating uncharacterized devices.

Contribution

It provides a universal security proof approach that bypasses the need for quantum error correction codes and applies to uncharacterized apparatuses.

Findings

Secure key rate derived for BB84 protocol with arbitrary source

Approach applicable to all cases previously treated by Shor and Preskill

Relieves constraints of quantum error correction codes

Abstract

We present an approach to the unconditional security of quantum key distribution protocols based on the uncertainty principle. The approach applies to every case that has been treated via the argument by Shor and Preskill, and relieve them from the constraints of finding quantum error correcting codes. It can also treat the cases with uncharacterized apparatuses. We derive a secure key rate for the Bennett-Brassard-1984 protocol with an arbitrary source characterized only by a single parameter representing the basis dependence.