Full-Blind Delegating Private Quantum Computation

TL;DR

This paper introduces a full-blind delegated quantum computation protocol that ensures both data and computation privacy, optimizing the Toffoli gate decryption circuit and using a fixed gate sequence for enhanced blindness.

Contribution

The paper proposes a novel full-blind DQC protocol with optimized Toffoli decryption and fixed gate sequences to achieve comprehensive blindness in delegated quantum computation.

Findings

Protocol correctly performs delegated quantum computations.

Achieves data blindness and computation blindness.

Optimizes Toffoli gate decryption circuit.

Abstract

The delegating private quantum computation (DQC) protocol with the universal quantum gate set $\left\{ {X,Z,H,P,R,CNOT} \right\}$ was firstly proposed by Broadbent \emph{et al.}, and then Tan \emph{et al.} tried to put forward an half-blind DQC protocol (HDQC) with another universal set $\left\{ {H,P,CNOT,T} \right\}$. However, the decryption circuit of \emph{Toffoli} gate (i.e., \emph{T}) is a little redundant, and Tan \emph{et al}.'s protocol exists the information leak. In addition, both of these two protocols just focus on the blindness of data (i.e., the client's input and output), but do not consider the blindness of computation (i.e., the delegated quantum operation). For solving these problems, we propose a full-blind DQC protocol (FDQC) with quantum gate set $\left\{ {H,P,CNOT,T} \right\}$ , where the desirable delegated quantum operation, one of $\left\{ {H,P,CNOT,T} \right\}$ , is replaced by a fixed sequence $\left \{ {H,P,T,CZ,CNOT} \right\}$ to make the computation blind, and the decryption circuit of \emph{Toffoli} gate is also optimized. Analysis shows that our protocol can not only correctly perform any delegated quantum computation, but also holds the characteristics of data blindness and computation blindness.