Flow Ambiguity: A Path Towards Classically Driven Blind Quantum Computation

TL;DR

This paper introduces a novel blind quantum computation protocol enabling a fully classical client to securely delegate quantum computations to a single quantum server by exploiting flow ambiguity in measurement-based quantum computing.

Contribution

It demonstrates how classical clients can leverage flow ambiguity to hide computation details in a single-server blind quantum protocol, a first in the field.

Findings

Classical clients can securely delegate quantum tasks using flow ambiguity.

The protocol hides critical computation aspects from the quantum server.

It advances blind quantum computing towards fully classical client scenarios.

Abstract

Blind quantum computation protocols allow a user to delegate a computation to a remote quantum computer in such a way that the privacy of their computation is preserved, even from the device implementing the computation. To date, such protocols are only known for settings involving at least two quantum devices: either a user with some quantum capabilities and a remote quantum server or two or more entangled but noncommunicating servers. In this work, we take the first step towards the construction of a blind quantum computing protocol with a completely classical client and single quantum server. Specifically, we show how a classical client can exploit the ambiguity in the flow of information in measurement-based quantum computing to construct a protocol for hiding critical aspects of a computation delegated to a remote quantum computer. This ambiguity arises due to the fact that, for a fixed graph, there exist multiple choices of the input and output vertex sets that result in deterministic measurement patterns consistent with the same fixed total ordering of vertices. This allows a classical user, computing only measurement angles, to drive a measurement-based computation performed on a remote device while hiding critical aspects of the computation.