A Fair Sampling Test for Ekert Protocol

TL;DR

This paper introduces a local, non-disruptive fair sampling test for the Ekert quantum key distribution protocol to detect biased sampling attacks that could fake Bell inequality violations.

Contribution

It presents a novel local scheme that enhances security by detecting biased sampling attempts during quantum key distribution.

Findings

The test can be performed unilaterally by Alice or Bob.

It effectively detects biased sampling attacks.

It operates alongside the Bell inequality test without disruption.

Abstract

We propose a local scheme to enhance the security of quantum key distribution in Ekert protocol (E91). Our proposal is a fair sampling test meant to detect an eavesdropping attempt that would use a biased sample to mimic an apparent violation of Bell inequalities. The test is local and non disruptive: it can be unilaterally performed at any time by either Alice or Bob during the production of the key, and together with the Bell inequality test.