Quantum Private Comparison Protocol Research Articles

A class of protocols for quantum private comparison based on the symmetry of states

In this paper, a class of protocols for quantum private comparison is investigated. The main feature is that the symmetry of quantum states is utilized. First of all, we design a new protocol for quantum private comparison via the $$\chi $$?-type state as a special example. Then, through the in-deep research and analysis on the quantum carrier, it is found that lots of quantum states with the symmetrical characteristic can be utilized to perform the protocol successfully. It is an attractive advantage in the practical application. What is more, two players are only required to be equipped with the unitary operation machines. It means that our protocols can easily be realized and have a broad scope of application. Finally, the analyses on the protocols' security, which are mainly ensured by the symmetry of quantum states and the property of the decoy state, are given in detail.

Erratum to: Same Initial States Attack in Yang et al.’s Quantum Private Comparison Protocol and the Improvement

Erratum to: Same Initial States Attack in Yang et al.’s Quantum Private Comparison Protocol and the Improvement

Comment on the “Quantum Private Comparison Protocol Based on Bell Entangled States”

Recently, Liu et al. proposed a quantum private comparison (QPC) based on Bell entangled states (Liu et al. in Commun. Theor. Phys. 57(4): 583, 2012). This paper points out a security loophole in Liu et al.’s protocol, in which the third party can disclose the private information of both users. In addition, an improvement is proposed to avoid the loophole.

Quantum private comparison of equality protocol without a third party

This paper presents a novel quantum private comparison protocol that uses Einstein---Podolsky---Rosen pairs. The proposed protocol allows two parties to secretly compare their information without exposing their actual contents. The technique of entanglement swapping enables the comparison to be achieved without the help of a third party. Moreover, because the proposed protocol employs one-step transmission and decoy photons, it is secure against the various quantum attacks in existence thus far.

Same Initial States Attack in Yang et al.’s Quantum Private Comparison Protocol and the Improvement

In Yang et al.’s literatures (J. Phys. A: Math. 42, 055305, 2009; J. Phys. A: Math. 43, 209801, 2010), a quantum private comparison protocol based on Bell states and hash function is proposed, which aims to securely compare the equality of two participants’ information with the help of a dishonest third party (TP). However, this study will point out their protocol cannot resist a special kind of attack, TP’s same initial states attack, which is presented in this paper. That is, the dishonest TP can disturb the comparison result without being detected through preparing the same initial states. Finally, a simple improvement is given to avoid the attack.

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.

Quantum Private Comparison of Equality with χ-Type Entangled States

In this paper, a quantum private comparison protocol with χ-type entangled states is proposed. In the protocol, two users can determine whether their secret inputs are equal, with the help of a semi-trusted third party. Here, the only constraint condition of this third party is that he could not collude with one user. Although the third party takes part in the whole process of the presented protocol, a feature of χ-type entangled state is utilized to design a eavesdropping check method to stand against his attack. Security analysis showed that the presented protocol is secure against some well-known attacks. Meanwhile, all the particles undergo only a one-way trip, which improves the efficiency and security of the presented protocol. Furthermore, only two-particle measurement is required in the implementation of the protocol, which make it more feasible in technique.

CRYPTANALYSIS AND IMPROVEMENTS FOR THE QUANTUM PRIVATE COMPARISON PROTOCOL USING EPR PAIRS

In this paper, we carry out an in-depth analysis of the quantum private comparison (QPC) protocol with the semi-honest third party (TP). The security of QPC protocol using the EPR pairs is re-examined. Unfortunately, we find that TP can use the fake EPR pairs to steal all the secret information. Furthermore, we give two simple and feasible solutions to improve the original QPC protocol. It is shown that the improved protocol is secure, which can resist various kinds of attacks from both the outside eavesdroppers and the inside participants, even the semi-honest TP.

Cryptanalysis of the secure quantum private comparison protocol

Recently, Yang et al [2009 Phys. Scr.80 065002] presented the first quantum private comparison protocol that involves single photons only. This protocol is very promising in practice. However, in this paper, we analyze the security of the protocol and point out a subtle loophole. It is shown that both Eve and Charlie could obtain Bob's secret by launching a special dense-coding attack. Moreover, details of this attack and its correctness are given, and also two solutions are demonstrated to improve the protocol in order to overcome the fatal flaw.

Quantum Private Comparison Protocol with the Random Rotation

We proposed a quantum secret comparison protocol for two parties with the random rotation angle, which is under the help of a semi-honest third party. The random rotation angle made it possible for the protocol to be safer and the two parties cannot deduce each other’s information by means of their own possessions. The participants’ secrets are divided into groups and the third party announced the results by group, which made the protocol more safely and sometimes it can save lots of resources. Moreover, during our protocol process any information of the two parties will not be leaked, even the third party cannot get any participants’ secrets.

Fault-Tolerate Quantum Private Comparison Based on GHZ States and ECC

There are some quantum private comparison (QPC) schemes proposed previously. In this paper we study these QPC protocols in non-ideal scenario and find that they are not secure there. For resolving the problem, we propose a QPC scheme which could be performed in practical scenario. By the use of Greenberger-Horne-Zeilinger (GHZ) states and error-correcting code (ECC), the scheme has the capability of fault-tolerate.

Comment on “Efficient and feasible quantum private comparison of equality against the collective amplitude damping noise”

Recently, Chen et al. [Quant Inf Proc doi: 10.1007/s11128-012-0505-5 ] presented a very promising quantum private comparison protocol for two participants to compare the equality of their wealth secretly--no one, except the participants, can reveal the comparison result. This paper points out that a malicious participant can reveal portion of the other participant's secret information. Furthermore, an improvement is also proposed.

Quantum private comparison protocol based on entanglement swapping of $$d$$ -level Bell states

In this paper, we propose a quantum private comparison protocol based on entanglement swapping, where two distrustful parties can compare the values of their secrets with the help of a semi-trusted third party. The protocol can determine not only whether two secrets are equal, but also the size relationship between them. The two parties can deduce the comparison result based on the keys shared between them and the announcement of the third party. Others including the third party will learn nothing about the values of the secrets, as well as the comparison result. The security of our protocol is analyzed. Furthermore, all the particles can be reused in the same protocol model theoretically. So our protocol is efficient and feasible to expand in network service, which in turn gives a solution to the left problem in Lin et al. (Quantum Inf Process, doi: 10.1007/s11128-012-0395-6 , 2012).

Quantum Private Comparison Based on Quantum Search Algorithm

We propose two quantum private comparison protocols based on quantum search algorithm with the help of a semi-honest third party. Our protocols utilize the properties of quantum search algorithm, the unitary operations, and the single-particle measurements. The security of our protocols is discussed with respect to both the outsider attack and the participant attack. There is no information leaked about the private information and the comparison result, even the third party cannot know these information.

Cryptanalysis and improvement of the quantum private comparison protocol with semi-honest third party

Recently, a quantum private comparison (QPC) protocol with a dishonest third party (TP) (Yang et al. in Quantum Inf Process, 2012. doi: 10.1007/s11128-012-0433-4 ) was proposed, which pointed out that the assumption of semi-honest third party (TP) is unreasonable. Here we find this protocol is not so secure as it was expected, and then we give some improvement strategies, which ensure that both players' secrets will not be leaked to anyone. We also discuss the assumption for TP in QPC protocls, which gives a constructive suggestions for the design of a new QPC protocol.

Efficient and feasible quantum private comparison of equality against the collective amplitude damping noise

In this paper, the new protocol for quantum private comparison of equality (QPCE) is investigated. Instead of using the entanglement, we only utilize the single photon to efficiently realize the comparison of secret information. Furthermore, a more feasible QPCE protocol, which can be successfully performed via the collective amplitude damping channel, is put forward. In our QPCE protocols, a semi-honest third party (TP) is involved. It is an appealing advantage in the practical implementation of protocol. Our QPCE protocols can resist various kinds of attacks from both the outside eavesdroppers and the inside participants, even the semi-honest TP.

Quantum Private Comparison Protocol Based on Cluster States

We present a quantum private comparison (QPC) protocol, enabling two players to compare the equality of their information without revealing any information about their respective private inputs, in which the four-particle cluster states as the information carriers are used. The presented protocol can ensure correctness, privacy, and fairness with the assistance of a semi-trusted third party (TP). Meanwhile, the participants including the TP are just required having the ability to perform single-particle measurements, which make the presented protocol more feasible in technique. Furthermore, the photon transmission is a one-way distribution; the Trojan horse attacks can be automatically avoided. The security of this protocol is also analyzed.

NEW QUANTUM PRIVATE COMPARISON PROTOCOL WITHOUT ENTANGLEMENT

After analyzing the main quantum private comparison (QPC) protocols based on the entanglement states, we propose a new QPC protocol using only polarized single photons. It will be shown that entanglement is not necessary for QPC. Most importantly, it will be pointed out that QPC protocols can be constructed by adapting the current quantum three-party secret sharing models properly.

Multi-user private comparison protocol using GHZ class states

This paper proposes a pioneering quantum private comparison (QPC) protocol for n users. State-of-the-art QPC protocols have been designed for two users who wish to compare their private information...

Quantum Private Comparison Based on GHZ Entangled States

We present a new quantum private comparison protocol based on the three-particle GHZ states. In this protocol, we prepare two types of GHZ states and use their entanglement properties to encode and compare the private information of X and Y. We also discuss that our protocol can withstand all various kinds of outside attacks and participant attacks.