Device-independent quantum key distribution with single-photon sources

TL;DR

This paper introduces new photonic protocols for device-independent quantum key distribution using single-photon sources and heralding architectures, significantly improving key rates and distances while making the process resilient to transmission losses.

Contribution

The work presents novel protocols that leverage single-photon sources and heralding architectures, enhancing security and performance in device-independent quantum key distribution.

Findings

Heralding process makes security independent of transmission losses.

Single-photon sources improve key rates and distances.

Protocols are feasible with current single-photon source technology.

Abstract

Device-independent quantum key distribution protocols allow two honest users to establish a secret key with minimal levels of trust on the provider, as security is proven without any assumption on the inner working of the devices used for the distribution. Unfortunately, the implementation of these protocols is challenging, as it requires the observation of a large Bell-inequality violation between the two distant users. Here, we introduce novel photonic protocols for device-independent quantum key distribution exploiting single-photon sources and heralding-type architectures. The heralding process is designed so that transmission losses become irrelevant for security. We then show how the use of single-photon sources for entanglement distribution in these architectures, instead of standard entangled-pair generation schemes, provides significant improvements on the attainable key rates and distances over previous proposals. Given the current progress in single-photon sources, our work opens up a promising avenue for device-independent quantum key distribution implementations.