In this paper, we present an innovative quantum dialogue protocol for multiple users to get private information from each other without leaking any information. In our protocol, a semi-honest third party (TP) is introduced to assist multiple participants for exchanging their private information. Specifically, exploiting multi-particle entangled GHZ states as the information carriers, we investigate how to implement the multi-party quantum dialogue protocol and perform the equivalence comparison. We also analyze the security of our protocol. Compared with previous quantum dialogue protocols, our protocol is more flexible and more efficient.
In this paper, we present an innovative quantum dialogue protocol for multiple users to get private information from each other without leaking any information. In our protocol, a semi-honest third party (TP) is introduced to assist multiple participants for exchanging their private information. Specifically, exploiting multi-particle entangled GHZ states as the information carriers, we investigate how to implement the multi-party quantum dialogue protocol and perform the equivalence comparison. We also analyze the security of our protocol. Compared with previous quantum dialogue protocols, our protocol is more flexible and more efficient.
A controlled multi-party quantum dialogue scheme in the network based on high dimensional multi-qudit entangled GHZ states is proposed. In our scheme, a semi-honest third party (TP) is introduced to assist the implementation of the scheme. Each user can be thought of as one node in the network and is connected by classical links and quantum links. In the network, multiple users can exchange their private messages with each other simultaneously under the control of TP. With the aid of secure classical channels and quantum channels, the proposed protocol can be ensured with unconditionally security. In addition, our protocol requires single-qudit measurements only which weakens the hardware requirements of network nodes. Compared with previous quantum dialogue protocols, our scheme demonstrates a large operating flexibility.
Abstract In this paper, we propose two multi-party quantum private comparison protocols based on the properties of the d-dimensional GHZ state. Protocol 1 is designed to compare the equality of multiple participants’ secrets with the help of a semi-honest third party TP. The semi-honest TP will follow the protocol honestly, but he may attempt to learn additional information from the protocol execution. In this protocol, multiple participants encode their secret information into the corresponding particles in turn through unitary operations, thereby achieving the comparison of the equality of their multiple secrets in a single execution. This protocol has a wide range of applications. For example, by combining the basic model framework of this protocol with the Chinese Remainder Theorem, we propose Protocol 2. In this protocol, multiple participants compare the size relationships of their multiple secrets with the help of a semi-honest third party TP. Therefore, based on the same basic model framework, the two protocols proposed in this paper can be applied respectively to the comparison of the equality and the size relationships of multiple participants’ secrets. Importantly, the two protocols do not require pre-shared keys. Security analysis shows that the proposed protocols can resist various attacks, including entangle-measure attack, intercept-resend attack, third party attacks, and participant attacks.
The goal of semi-quantum privacy comparison (SQPC) is to use a small amount of quantum capabilities to compare private information for equality. In recent years, research on semi-quantum privacy comparison protocol has made some achievements. However, most of SQPC protocols can merely compare the private information of two parties, and the research of multi-party SQPC protocols are still scarce. If the number of participants is more than two, the protocol needs to be executed multiple times. Therefore, we proposed a multi-party semi-quantum private comparison protocol based on the maximally entangled GHZ-type state, which has the capability to compare the equality of n parties by executing the protocol once. What is more, the transmission of participant’s encrypted information is not through the classical channel, which improves the security of the protocol. Finally, the security analysis shows that outsider attacks, dishonest participants attacks and semi-honest TP attacks are all invalid for this protocol.
In this paper, an efficient quantum private comparison (QPC) protocol based on GHZ-type states is proposed. Two participants can compare the equality of two classical bits in each comparison, which could greatly reduce comparison times and increase efficiency. A semi-honest third-party (TP) is involved in assisting the participants to compare their secrets. TP may misbehave on her own, but she is not allowed to conspire with any participants. Besides, the proposed protocol needs Hadamard operation as well as single-particle measurements and Bell measurements, which are easy to implement with current technologies. Finally, the analysis shows the proposed protocol is correct and it can resist various attacks including outside attacks and dishonest participant attacks.
Multiparty quantum private comparison (MQPC) aims to determine the equality relationship of inputs from multiple participants while maintaining the confidentiality of these inputs. Current MQPC protocols primarily focus on utilizing d-level quantum states, which limits feasible implementation. To address this issue, we introduce an MQPC protocol that utilizes n-particle Greenberger–Horne–Zeilinger (GHZ) state to enable private comparison while preserving the secrecy of individual inputs. A semi-honest third party (TP), adhering to protocol specifications but potentially curious about private data, generates and distributes GHZ state qubits to all participants. Each party encodes their secret input through rotation operations on their allocated qubits and returns the modified state to the TP, which then performs single-particle quantum measurements to derive the outcomes without accessing the raw inputs. The protocol’s sequence distribution method yields a high qubit efficiency of 1/n, outperforming many existing MQPC protocols. Security analysis confirms resilience against external adversaries employing quantum attack strategies and collusion attempts among participants. Simulations using IBM Qiskit validate the feasibility of the protocol, which relies on GHZ state preparation, single-qubit operations, and single-particle quantum measurements.
Abstract An efficient multiparty semi‐quantum private comparison protocol based on Bell states is proposed. The proposed protocol enables the comparison of private information equality among multiple classical participants with the assistance of two semi‐honest third parties. Unlike previous protocols, the proposed protocol can be further extended to resist the collective‐dephasing noise and the collective‐rotation noise, respectively. The proposed protocol and its extensions do not require the classical participants to generate and send new quantum states to the third party, and these participants can compare two privacies within one round of comparison. In addition, the protocol performs better with a qubit efficiency up to 25%. The security analysis indicates that the protocol is resilient to various known quantum attacks. Furthermore, the feasibility of this protocol is confirmed by simulation results on the IBM quantum platform.