Efficient Quantum Private Comparison Research Articles

Efficient Quantum Private Comparison with Unitary Operations

Quantum private comparison (QPC) is a crucial component of quantum multiparty computing (QMPC), allowing parties to compare their private inputs while ensuring that no sensitive information is disclosed. Many existing QPC protocols that utilize Bell states encounter efficiency challenges. In this paper, we present a novel and efficient QPC protocol that capitalizes on the distinct characteristics of Bell states to enable secure comparisons. Our method transforms private inputs into unitary operations on shared Bell states, which are then returned to a third party to obtain the comparison results. This approach enhances efficiency and decreases the reliance on complex quantum resources. A single Bell state can compare two classical bits, achieving a qubit efficiency of 100%. We illustrate the feasibility of the protocol through a simulation on the IBM Quantum Cloud Platform. The security analysis confirms that our protocol is resistant to both eavesdropping and attacks from participants.

Efficient Quantum Private Comparison Based on GHZ States.

Quantum private comparison (QPC) is a fundamental cryptographic protocol that allows two parties to compare the equality of their private inputs without revealing any information about those inputs to each other. In recent years, QPC protocols utilizing various quantum resources have been proposed. However, these QPC protocols have lower utilization of quantum resources and qubit efficiency. To address this issue, we propose an efficient QPC protocol based on GHZ states, which leverages the unique properties of GHZ states and rotation operations to achieve secure and efficient private comparison. The secret information is encoded in the rotation angles of rotation operations performed on the received quantum sequence transmitted along the circular mode. This results in the multiplexing of quantum resources and enhances the utilization of quantum resources. Our protocol does not require quantum key distribution (QKD) for sharing a secret key to ensure the security of the inputs, resulting in no consumption of quantum resources for key sharing. One GHZ state can be compared to three bits of classical information in each comparison, leading to qubit efficiency reaching 100%. Compared with the existing QPC protocol, our protocol does not require quantum resources for sharing a secret key. It also demonstrates enhanced performance in qubit efficiency and the utilization of quantum resources.

Efficient Quantum Private Comparison without Sharing a Key.

Quantum private comparison (QPC) allows at least two users to compare the equality of their secret information, for which the security is based on the properties of quantum mechanics. To improve the use of quantum resources and the efficiency of private comparison, a new QPC protocol based on GHZ-like states is proposed. The protocol adopts unitary operations to encode the secret information instead of performing quantum key distribution (QKD), which can reduce the amount of computation required to perform QKD and improve the utilization of quantum resources. The decoy photon technique used to detect channel eavesdropping ensures that the protocol is resistant to external attacks. The quantum efficiency of the protocol reaches 66%. Compared with many previous QPC schemes, the proposed protocol does not need to share a key and has advantages in quantum efficiency and quantum resources.

Efficient quantum private comparison protocol utilizing single photons and rotational encryption

As a branch of quantum secure multiparty computation, quantum private comparison is applied frequently in many fields, such as secret elections, private voting, and identification. A quantum private comparison protocol with higher efficiency and easier implementation is proposed in this paper. The private secrets are encoded as single polarized photons and then encrypted with a homomorphic rotational encryption method. Relying on this method and the circular transmission mode, we implement the multiplexing of photons, raising the efficiency of our protocol to 100%. Our protocol is easy to realize since only single photons, unitary operation, and single-particle measurement are introduced. Meanwhile, the analysis shows that our protocol is also correct and secure.

Efficient quantum private comparison protocol based on one direction discrete quantum walks on the circle

We propose an efficient quantum private comparison protocol firstly based on one direction quantum walks. With the help of one direction quantum walk, we develop a novel method that allows the semi-honest third party to set a flag to judge the comparing result, which improves the qubit efficiency and the maximum quantity of the participants’ secret messages. Besides, our protocol can judge the size of the secret messages, not only equality. Furthermore, the quantum walks particle is disentangled in the initial state. It only requires a quantum walks operator to move, making our proposed protocol easy to implement and reducing the quantum resources. Through security analysis, we prove that our protocol can withstand well-known attacks and brute-force attacks. Analyses also reveal that our protocol is correct and practical.

Efficient Quantum Private Comparison Based on Entanglement Swapping of Bell States

Efficient Quantum Private Comparison Based on Entanglement Swapping of Bell States

A Novel and Efficient Quantum Private Comparison Scheme

A quantum private comparison is a primitive protocol of secure multiparty quantum computation that enables two parties to privately decide whether x = y or not, given two integers x and y, that are held as private inputs by the two parties, respectively. However, many existing quantum private comparison schemes may not be efficient enough, especially applied in big-data and large-scale network environments, because of low efficiency bit-by-bit comparisons. In this paper, we present a novel and efficient quantum private comparison scheme. The proposed scheme provides higher communication efficiency because a secret-by-secret comparison instead of a bit-by-bit comparison is used.

Efficient quantum private comparison protocol based on the entanglement swapping between four-qubit cluster state and extended Bell state

Quantum private comparison (QPC) protocol can guarantee the two participants to compare the equality of their private information without leaking them. Based on the entanglement swapping between the four-qubit cluster state and extended Bell state, an efficient QPC protocol has been proposed. Three bits of the secret inputs have been compared in each comparison time, which improves the efficiency compared with the previous QPC protocols’ one or two bits. Then, based on a random sequence pre-shared between the two participants, the semi-honest third party can only execute the protocol’s process without obtaining the information of the participants’ secrets and comparison results. Last, various kinds of attacks have been analyzed, which show that the proposed protocol is secure against the outside and participants attacks.

A Robust and Efficient Quantum Private Comparison of Equality Based on the Entangled Swapping of GHZ-like State and χ + State

A new quantum protocol with the assistance of a semi-honest third party (TP) is proposed, which allows the participants comparing the equality of their private information without disclosing them. Different from previous protocols, this protocol utilizes quantum key distribution against the collective-dephasing noise and the collective-rotation noise, which is more robust and abandons few samples, to transmit the classical information. In addition, this protocol utilizes the GHZ-like state and the χ + state to produce the entanglement swapping. And the Bell basis and the dual basis are used to measure the particle pair so that 3 bits of each participant’s private information can be compared in each comparison time, which is more efficient and consumes fewer comparison times. Meanwhile, there is no need of unitary operation and hash function in this protocol. At the end, various kinds of outside attack and participant attack are discussed and analyzed to be invalid, so it can complete the comparison in security.

An Efficient Quantum Private Comparison of Equality over Collective-Noise Channels

This article proposes a collective-noise resistant QPC protocol with the help of an almostdishonest third party (TP) who may try to perform any sort of attacks to derive participants’ private secrets except colluding with any participant. The proposed scheme has some considerable advantages over the state-of-the-art QPC protocols over collective-noise channels, where it does not require any pre-shared key between the participants (Alice and Bob). Nevertheless, the proposed scheme can resist Trojan horse attacks without consuming half of the transmitted qubits and any additional equipment (wavelength filter and PNS) support. As a consequence, the proposed QPC protocol can guarantee higher qubit efficiency as compared to the others over collective noise channels.

Quantum private comparison protocol with cloud quantum computing

SummaryBecause privacy problems with big data impede progress at all phases of the pipeline that can create value from data, Alice and Bob have to perform private queries in order to obtain the private comparison results of big data. Suppose that the cloud devices are with the capacity of conventional and quantum computation, an efficient quantum private comparison protocol with ring‐trip transmission by safe cloud quantum computing in the quantum Internet is proposed. Two participant parties Alice and Bob, with the help of a semi‐trusted third party and cloud device by simple quantum measurements and mathematical operation, can compare the equality of their secret information without revealing the content of secret information. We show that our protocol can resist the eavesdropper Eve's intercept–resend attack, entangle–measure attack, and Trojan horse attack to cloud device, participant's intercept–measure–resend attack, and third party's attack. The qubit efficiency of our protocol approaches to 100%. We also analyze the connection between Eve's obtained information and the fidelity of secret information in detail. Copyright © 2015 John Wiley & Sons, Ltd.

Robust and efficient quantum private comparison of equality with collective detection over collective-noise channels

We present a protocol for quantum private comparison of equality (QPCE) with the help of a semi-honest third party (TP). Instead of employing the entanglement, we use single photons to achieve the comparison in this protocol. By utilizing collective eavesdropping detection strategy, our protocol has the advantage of higher qubit efficiency and lower cost of implementation. In addition to this protocol, we further introduce three robust versions which can be immune to collective dephasing noise, collective-rotation noise and all types of unitary collective noise, respectively. Finally, we show that our protocols can be secure against the attacks from both the outside eavesdroppers and the inside participants by using the theorems on quantum operation discrimination.

Efficient quantum private comparison employing single photons and collective detection

Two efficient quantum private comparison (QPC) protocols are proposed, employing single photons and collective detection. In the proposed protocols, two distrustful parties (Alice and Bob) compare the equivalence of information with the help of a semi-honest third party (TP). Utilizing collective detection, the cost of practical realization is reduced greatly. In the first protocol, TP gains the result of the comparison. While in the second protocol, TP cannot get the comparison result. In both of our protocols, Alice and Bob only need be equipped with unitary operation machines, such as phase plates. So Alice and Bob need not to have the expensive quantum devices, such as qubit generating machine, quantum memory machine and quantum measuring machine. Security of the protocols is ensured by theorems on quantum operation discrimination.

An efficient two-party quantum private comparison protocol with decoy photons and two-photon entanglement

Following some ideas of the quantum secret sharing (QSS) protocol (2008, Phys. Lett. A 372, 1957), we propose an efficient quantum private comparison (QPC) protocol for comparing information of equality with the help of a third party (TP). The protocol can ensure fairness, efficiency and security. The protocol is fair, which means that one party knows the sound result of the comparison if and only if the other one knows the result. The protocol is efficient with the help of the TP for calculating. However, the TP cannot learn any information about the players' respective private inputs and even about the comparison result and cannot collude with any player. The protocol is secure for the two players, that is, any information about their respective secret inputs will not leak except the final computation result. A precise proof of security of the protocol is presented. Applications of this protocol may include private bidding and auctions, secret ballot elections, commercial business, identification in a number of scenarios and so on.