Measurement-device-independent quantum key distribution for nonstandalone networks

TL;DR

This paper proposes a cost-effective method to upgrade existing phase-encoding BB84 quantum key distribution networks to measurement-device-independent networks, enhancing security, compatibility, and network survivability without hardware changes.

Contribution

It introduces an NSA-MDI scheme inspired by 5G nonstandalone networks, enabling immediate MDI support in existing BB84 networks with various phase-encoding schemes.

Findings

Supports immediate MDI upgrade without hardware changes

Enhances security and bandwidth flexibility

Improves network survivability

Abstract

Untrusted node networks initially implemented by measurement-device-independent quantum key distribution (MDI-QKD) protocol are a crucial step on the roadmap of the quantum Internet. Considering extensive QKD implementations of trusted node networks, a workable upgrading tactic of existing networks toward MDI networks needs to be explicit. Here, referring to the nonstandalone (NSA) network of 5G, we propose an NSA-MDI scheme as an evolutionary selection for existing phase-encoding BB84 networks. Our solution can upgrade the BB84 networks and terminals that employ various phase-encoding schemes to immediately support MDI without hardware changes. This cost-effective upgrade effectively promotes the deployment of MDI networks as a step of untrusted node networks while taking full advantage of existing networks. In addition, the diversified demands on security and bandwidth are satisfied, and network survivability is improved.