Device independent quantum key distribution with robust self-tests

TL;DR

This paper introduces a method to convert device-independent quantum key distribution protocols into device-dependent ones using local self-tests, demonstrated through a routed BB84 protocol case study.

Contribution

It presents a rigorous framework for transferring DIQKD assumptions to device-dependent QKD via local self-tests, enhancing practical implementation.

Findings

Framework successfully transfers DIQKD assumptions to device-dependent setting.

Self-testing via routed Bell-test setups is effective for local verification.

Application to routed BB84 protocol demonstrates practical viability.

Abstract

Device-independent quantum key distribution (DIQKD) provides a model of quantum key distribution with minimal assumptions and highly abstract theoretical building blocks. Although DIQKD frees us from detailed discussions of specific device models and associated error parameters, it replaces them with fundamental assumptions about the validity of quantum experiments. In this work, we propose a way to lift a protocol based on DIQKD-style assumptions to a device-dependent QKD protocol by performing local self-tests in the laboratories of the two key-generating parties. In particular, we consider routed Bell-test setups as a means of self-testing the local parties in earnest and develop a rigorous mathematical framework showing that the underlying optimization problems can indeed be transferred to the device-dependent QKD setting. As an application, we illustrate many of the relevant techniques through the case study of a routed BB84 protocol.