Multipartite entanglement verification resistant against dishonest parties

TL;DR

This paper presents a method for verifying multipartite entanglement in quantum networks that remains secure even with multiple dishonest parties, using minimal resources and a trusted common random source.

Contribution

It introduces a distributed verification protocol resistant to dishonest parties, with a tradeoff between security level and state fidelity, and enhanced security via a trusted random source.

Findings

Verification protocol is resistant to any number of dishonest parties.

A tight tradeoff between security level and state fidelity is established.

Adding a trusted random source enhances security guarantees for honest parties.

Abstract

Future quantum information networks will likely consist of quantum and classical agents, who have the ability to communicate in a variety of ways with trusted and untrusted parties and securely delegate computational tasks to untrusted large-scale quantum computing servers. Multipartite quantum entanglement is a fundamental resource for such a network and hence it is imperative to study the possibility of verifying a multipartite entanglement source in a way that is efficient and provides strong guarantees even in the presence of multiple dishonest parties. In this work, we show how an agent of a quantum network can perform a distributed verification of a multipartite entangled source with minimal resources, which is, nevertheless, resistant against any number of dishonest parties. Moreover, we provide a tight tradeoff between the level of security and the distance between the state produced by the source and the ideal maximally entangled state. Last, by adding the resource of a trusted common random source, we can further provide security guarantees for all honest parties in the quantum network simultaneously.