Secure multiparty quantum computation based on bit commitment

TL;DR

This paper presents a method for secure multiparty quantum computation using bit commitment, reducing the problem to secure two-party computation of NL-CNOT gates, and highlights vulnerabilities in existing protocols.

Contribution

It introduces a new SMQC scheme based on bit commitment that does not rely on trusted third parties and is secure against passive adversaries.

Findings

The scheme is secure in the passive adversaries model.

A reduction from SMQC to secure two-party NL-CNOT computation is established.

Vulnerabilities in existing NL-CNOT protocols are identified.

Abstract

This paper studies secure multiparty quantum computation (SMQC) without nonlocal measurements. Firstly, this task is reduced to secure two-party quantum computation of nonlocal controlled-NOT (NL-CNOT) gate. Then, in the passive adversaries model, the secure computation of NL-CNOT is reduced to bit commitment. Thus, a SMQC scheme can be constructed based on bit commitment. This scheme does not depend on trusted third party, and is secure in the passive adversaries model. It is also pointed out that a vulnerability exists in any secure two-party quantum computation protocol of NL-CNOT gate.