Device-Independent Secret Sharing and a Stronger Form of Bell Nonlocality

TL;DR

This paper demonstrates that a stronger form of Bell nonlocality enables device-independent secret sharing, advancing quantum communication by removing the need for trusted devices and ensuring secure information distribution.

Contribution

It introduces a new form of Bell nonlocality that surpasses traditional models and applies it to achieve device-independent secret sharing.

Findings

Stronger Bell nonlocality cannot be simulated by nonlocal hidden variable models.

Device-independent secret sharing is feasible using this stronger nonlocality.

The approach enhances security and trustworthiness in quantum communication protocols.

Abstract

Bell nonlocality, the fact that local hidden variable models cannot reproduce the correlations obtained by measurements on entangled states, is a cornerstone in our modern understanding of quantum theory. Apart from its fundamental implications, nonlocality is also at the core of device-independent quantum information processing, which successful implementation is achieved without precise knowledge of the physical apparatus. Here we show that a stronger form of Bell nonlocality, for which even nonlocal hidden variable models cannot reproduce the quantum predictions, allows for the device-independent implementation of secret sharing, a paradigmatic communication protocol where a secret split amidst many possibly untrusted parts can only be decoded if they collaborate among themselves.