Unifying communication paradigms in measurement-based delegated quantum computing

TL;DR

This paper unifies two primary paradigms in measurement-based delegated quantum computing, enabling protocols to be constructed and translated across different client-server interaction models.

Contribution

It introduces a method to build protocols in both prepare-and-send and receive-and-measure settings simultaneously, clarifying their interrelation.

Findings

Protocols can be translated between the two primary settings.

The method enables building protocols in both settings simultaneously.

It clarifies the theoretical constraints of each setting.

Abstract

Delegated quantum computing (DQC) allows clients with low quantum capabilities to outsource computations to a server hosting a quantum computer. This process is often envisioned within the measurement-based quantum computing framework, as it naturally facilitates blindness of inputs and computation. Hence, the overall process of setting up and conducting the computation encompasses a sequence of three stages: preparing the qubits, entangling the qubits to obtain the resource state, and measuring the qubits to run the computation. There are two primary approaches to distributing these stages between the client and the server that impose different constraints on cryptographic techniques and experimental implementations. In the prepare-and-send setting, the client prepares the qubits and sends them to the server, while in the receive-and-measure setting, the client receives the qubits from the server and measures them. Although these settings have been extensively studied independently, their interrelation and whether setting-dependent theoretical constraints are inevitable remain unclear. By implementing the key components of most DQC protocols in the respective missing setting, we provide a method to build prospective protocols in both settings simultaneously and to translate existing protocols from one setting into the other.