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.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.

arXiv:2002.00464Computers, materials & continua/Computers, materials & continua (Print)Feb 2, 202035 citations

Star-network multi-party semi-quantum private comparison with delegated measurement-device independence

Cao Meng-yan, Ri‐Gui Zhou, Lin-Tao Du

Abstract Multi-party semi-quantum private comparison (MSQPC) aims to determine equivalence relations among private inputs while requiring only restricted quantum operations at the user side. Representative existing approaches mainly provide global multi-party equality testing or selected pairwise comparisons, whereas a direct all-pairs construction requires a quadratic number of pairwise quantum links. We propose a star-network delegated measurement-device-independent MSQPC protocol that establishes only N − 1 hub–branch quantum masking correlations and recovers all N ( N − 1 ) / 2 pairwise equivalence relations, together with the corresponding equivalence-class partition, through classical algebraic elimination without pre-shared comparison keys. State preparation and measurement are separated between a semi-honest third party (TP) and an untrusted UTP, while decoherence-free subspace encoding and partial logical Bell-state measurement improve robustness against collective phase noise and measurement-side abnormalities. Under TP–UTP non-collusion, authenticated classical channels, secure commitment, sufficient conditional input min-entropy, and the session-digest pseudorandomness assumption, the protocol provides explicit finite-sample security verification while reducing the network-wide quantum-link requirement from quadratic to linear.Abstract Multi-party semi-quantum private comparison (MSQPC) aims to determine equivalence relations among private inputs while requiring only restricted quantum operations at the user side. Representative existing approaches mainly provide global multi-party equality testing or selected pairwise comparisons, whereas a direct all-pairs construction requires a quadratic number of pairwise quantum links. We propose a star-network delegated measurement-device-independent MSQPC protocol that establishes only N − 1 hub–branch quantum masking correlations and recovers all N ( N − 1 ) / 2 pairwise equivalence relations, together with the corresponding equivalence-class partition, through classical algebraic elimination without pre-shared comparison keys. State preparation and measurement are separated between a semi-honest third party (TP) and an untrusted UTP, while decoherence-free subspace encoding and partial logical Bell-state measurement improve robustness against collective phase noise and measurement-side abnormalities. Under TP–UTP non-collusion, authenticated classical channels, secure commitment, sufficient conditional input min-entropy, and the session-digest pseudorandomness assumption, the protocol provides explicit finite-sample security verification while reducing the network-wide quantum-link requirement from quadratic to linear.

Physica ScriptaOct 8, 20260 citations

Quantum Gate-Based Quantum Private Comparison

Yan‐Feng Lang

International Journal of Theoretical PhysicsJan 6, 202032 citations

Quantum Private Comparison Based on Quantum Search Algorithm

Weiwei Zhang, Dan Li, Tingting Song +1 more

International Journal of Theoretical PhysicsJan 11, 201326 citations

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.