Quantum Private Comparison Protocol Based on Bell Entangled States

In this paper,a quantum private comparison protocol is proposed based on bell entangled states.In our protocol,two parties can compare the equality of their information with the help of a semi-honest third party.The correctness and security of our protocol are discussed.One party cannot learn the other's private information and the third party also cannot learn any information about the private information.     

Multi-party Quantum Private Comparison Protocol Using d-Dimensional Basis States Without Entanglement Swapping

We present a new multi-party quantum private comparison protocol based on d-dimensional basis states. Different from previous protocols, our protocol have some advantages. n parties can determine wether their private information are equal or not in one time execution of our protocol. Without using the entangled character of d-dimensional basis states, we only need to perform the local unitary operation on particles to encode the information and to get the comparison result. We also discuss that our protocol can withstand various kinds of outside attacks and participant attacks.     

Multi-Party Quantum Private Comparison Protocol Based on Entanglement Swapping of Bell Entangled States

Recently, Liu et al. proposed a two-party quantum private comparison (QPC) protocol using entanglement swapping of Bell entangled state (Commun. Theor. Phys. 57 (2012) 583). Subsequently, Liu et al. pointed out that in Liu et al.'s protocol, the TP can extract the two users' secret inputs without being detected by launching the Bell-basis measurement attack, and suggested the corresponding improvement to mend this loophole (Commun. Theor. Phys. 62 (2014) 210). In this paper, we first point out the information leakage problem toward TP existing in both of the above two protocols, and then suggest the corresponding improvement by using the one-way hash function to encrypt the two users' secret inputs. We further put forward the three-party QPC protocol also based on entanglement swapping of Bell entangled state, and then validate its output correctness and its security in detail. Finally, we generalize the three-party QPC protocol into the multi-party case, which can accomplish arbitrary pair's comparison of equality among K users within one execution.     

Cryptanalysis and Improvement of Quantum Private Comparison Protocol Based on Bell Entangled States

Recently, Liu et al. [Commun. Theor. Phys. 57(2012) 583] proposed a quantum private comparison protocol based on entanglement swapping of Bell states, which aims to securely compare the equality of two participants' information with the help of a semi-honest third party(TP). However, the present study points out there is a fatal loophole in Liu et al.'s protocol, and TP can make Bell-basis measurement to know all the participants' secret inputs without being detected. To fix the problem, a simple solution, which uses one-time eavesdropper checking with decoy photons instead of twice eavesdropper checking with Bell states, is demonstrated. Compared with the original protocol,it not only reduces the Bell states consumption but also simplifies the protocol steps.     

Cryptanalysis and Improvement of Quantum Private Comparison Protocol Based on Bell Entangled States

Recently, Liu et al. [Commun. Theor. Phys. 57 (2012) 583] proposed a quantum private comparison protocol based on entanglement swapping of Bell states, which aims to securely compare the equality of two participants' information with the help of a semi-honest third party (TP). However, the present study points out there is a fatal loophole in Liu et al.'s protocol, and TP can make Bell-basis measurement to know all the participants' secret inputs without being detected. To fix the problem, a simple solution, which uses one-time eavesdropper checking with decoy photons instead of twice eavesdropper checking with Bell states, is demonstrated. Compared with the original protocol, it not only reduces the Bell states consumption but also simplifies the protocol steps.     

Quantum Private Comparison Protocol with W States

We propose a secure quantum protocol for comparing the equality of information with the help of a semi-honest third party (Trent). Our protocol utilizes the triplet W states, and the single-particle measurement. The technique for preparing W state is mature, which ensures the utility of our protocol. The security of our protocol with respect to both outsider attack and participant attack is discussed. Any information about the private information, the comparison result will not be leaked out, even the third party cannot know these information.     

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.     

Efficient Quantum Private Comparison Based on Entanglement Swapping of Bell States

International Journal of Theoretical Physics - In this paper, by using entanglement swapping of Bell states, an efficient quantum private comparison(QPC) protocol with a semi-honest party is...     

Multi-Party Quantum Private Comparison Protocol with an Almost-Dishonest Third Party using GHZ States

This article proposes an innovative quantum private comparison (QPC) protocol for n users using GHZ states, where an almost-dishonest third party (TP) is introduced to assist the participants for comparing their secrets. It is argued that as compared to the existing QPC protocols our proposed scheme has some considerable advantages. First, in the existing QPC protocols, the TP can only to determine whether all participants’ secrets are equal or not. Instead of that, in our proposed scheme a TP can even compare the secrets between any subsects of users. Second, since our proposed scheme is based on GHZ state; hence it can ensure higher efficiency as compared to other existing multi-party QPC protocols on d-dimension photons.     

Improvements of Quantum Private Comparison Protocol Based on Cluster States

Quantum private comparison aims to determine whether the secrets from two different users are equal or not by utilizing the laws of quantum mechanics. Recently, Sun and Long put forward a quantum private comparison (QPC) protocol by using four-particle cluster states (Int. J. Theor. Phys. 52, 212–218, 2013). In this paper, we investigate this protocol in depth, and suggest the corresponding improvements. Compared with the original protocol, the improved protocol has the following advantages: 1) it can release the requirements of authenticated classical channels and unitary operations; 2) it can prevent the malicious attack from the genuine semi-honest TP; 3) it can enhance the qubit efficiency.     

Quantum Private Comparison Using Single Bell State

International Journal of Theoretical Physics - Quantum private comparison (QPC) can tell us whether two users’ private data are equal or not by quantum technology without disclosing privacy...     

Novel Quantum Private Comparison Protocol Based on Locally Indistinguishable Product States

International Journal of Theoretical Physics - In this paper, we propose a two-party quantum private comparison (QPC) protocol using orthogonal product states. This protocol introduces a...     

Robust Multi-party Quantum Private Comparison Protocols Against the Collective Noise Based on Three-Qubit Entangled States

Recently, Ye and Ji constructed a multi-party quantum private comparison (MQPC) protocol with Bell entangled states (Sci. China Phys. Mech. Astron. 60(9), 090312, 2017). However, this protocol is only workable over an ideal quantum channel. In this paper, we take the collective noise channel into account and generalize Ye and Ji’s protocol into the ones against the collective-dephasing noise and the collective-rotation noise, respectively. Concretely, we use three-qubit entangled states instead of Bell states as the initial quantum states and employ the corresponding logical qubits immune to the collective noise instead of the physical qubits as the travelling particles. The output correctness and the security of the proposed robust MQPC protocols can be guaranteed.     

Multi-Party Quantum Private Comparison Based on Entanglement Swapping of Bell Entangled States within d-Level Quantum System

International Journal of Theoretical Physics - In this paper, a multi-party quantum private comparison (MQPC) scheme is suggested based on entanglement swapping of Bell entangled states within...     

Novel Multi-Party Quantum Key Agreement Protocol with G-Like States and Bell States

A significant aspect of quantum cryptography is quantum key agreement (QKA), which ensures the security of key agreement protocols by quantum information theory. The fairness of an absolute security multi-party quantum key agreement (MQKA) protocol demands that all participants can affect the protocol result equally so as to establish a shared key and that nobody can determine the shared key by himself/herself. We found that it is difficult for the existing multi-party quantum key agreement protocol to withstand the collusion attacks. Put differently, it is possible for several cooperated and untruthful participants to determine the final key without being detected. To address this issue, based on the entanglement swapping between G-like state and Bell states, a new multi-party quantum key agreement protocol is put forward. The proposed protocol makes full use of EPR pairs as quantum resources, and adopts Bell measurement and unitary operation to share a secret key. Besides, the proposed protocol is fair, secure and efficient without involving a third party quantum center. It demonstrates that the protocol is capable of protecting users’ privacy and meeting the requirement of fairness. Moreover, it is feasible to carry out the protocol with existing technologies.     

Quantum Private Comparison Protocol with Linear Optics

In this paper, we propose an innovative quantum private comparison(QPC) protocol based on partial Bell-state measurement from the view of linear optics, which enabling two parties to compare the equality of their private information with the help of a semi-honest third party. Partial Bell-state measurement has been realized by using only linear optical elements in experimental measurement-device-independent quantum key distribution(MDI-QKD) schemes, which makes us believe that our protocol can be realized in the near future. The security analysis shows that the participants will not leak their private information.     

High-Efficiency Three-Party Quantum Key Agreement Protocol with Quantum Dense Coding and Bell States

We propose a high-efficiency three-party quantum key agreement protocol, by utilizing two-photon polarization-entangled Bell states and a few single-photon polarization states as the information carriers, and we use the quantum dense coding method to improve its efficiency. In this protocol, each participant performs one of four unitary operations to encode their sub-secret key on the passing photons which contain two parts, the first quantum qubits of Bell states and a small number of single-photon states. At the end of this protocol, based on very little information announced by other, all participants involved can deduce the same final shared key simultaneously. We analyze the security and the efficiency of this protocol, showing that it has a high efficiency and can resist both outside attacks and inside attacks. As a consequence, our protocol is a secure and efficient three-party quantum key agreement protocol.

     

Multi-Party Quantum Key Distribution Protocol with New Bell States Encoding Mode

International Journal of Theoretical Physics - Security, efficiency and universality are the major concerns in distributed computation for how to communicate securely as there are a large number of...     

Multi-Party Quantum Key Agreement Protocol with Bell States and Single Particles

International Journal of Theoretical Physics - Liu et al. [Quantum Inf. Process. 12, 1797–1805 (2013)] proposed a multi-party quantum key agreement (QKA) protocol based on single particles....     

Quantum Dialogue Protocol Based on Bell Entangled States and Single Photons

International Journal of Theoretical Physics - In this paper, inspired by Wang et al.’s deterministic secure quantum communication (DSQC) scheme (Commun. Theor. Phys. 60 (2013)...