The purpose of quantum private comparison (QPC) is to solve “Tiercé problem” using quantum mechanics laws, where the “Tiercé problem” is to judge whether the secret data of two participants are equal under the condition of protecting data privacy. Here we consider for the first time the usefulness of eight-qubit entangled states for QPC by proposing a new protocol. The proposed protocol only adopts necessary quantum technologies such as preparing quantum states and quantum measurements without using any other quantum technologies (e.g. unitary operations and entanglement swapping), thus the protocol has advantages in quantum device consumption. The measurements adopted only include single-particle measurements, which is easier to implement than entangled-state measurements under the existing technical conditions. The proposed protocol takes advantage of the entanglement characteristics of the eight-qubit entangled state, and uses joint computation, decoy photon technology, the keys generated by a quantum key distribution protocol to ensure data privacy. We show that when all single-particle measurements in the proposed protocol are replaced by Bell measurements, the purpose of the protocol can also be achieved. We also show that the proposed protocol can be changed into a semi-quantum protocol with a few small changes.
The purpose of quantum private comparison (QPC) is to solve “Tiercé problem” using quantum mechanics laws, where the “Tiercé problem” is to judge whether the secret data of two participants are equal under the condition of protecting data privacy. Here we consider for the first time the usefulness of eight-qubit entangled states for QPC by proposing a new protocol. The proposed protocol only adopts necessary quantum technologies such as preparing quantum states and quantum measurements without using any other quantum technologies (e.g. unitary operations and entanglement swapping), thus the protocol has advantages in quantum device consumption. The measurements adopted only include single-particle measurements, which is easier to implement than entangled-state measurements under the existing technical conditions. The proposed protocol takes advantage of the entanglement characteristics of the eight-qubit entangled state, and uses joint computation, decoy photon technology, the keys generated by a quantum key distribution protocol to ensure data privacy. We show that when all single-particle measurements in the proposed protocol are replaced by Bell measurements, the purpose of the protocol can also be achieved. We also show that the proposed protocol can be changed into a semi-quantum protocol with a few small changes.
Quantum private comparison (QPC), whose security is based on some laws of quantum mechanics (e.g. quantum noncloning theorem and Heisenbergs uncertainty principle), allows [Formula: see text] parties who do not trust each other to judge whether their secret data are the same while maintaining data privacy. In this paper, we investigate the utility of the maximally entangled seven-qubit state for QPC, and we propose a new protocol which enables two parties to compare their secret data with each other for equality without disclosing their secret data. In our protocol, single particle measurements and Bell-basis measurements are employed, both of which can be implemented with current technologies. In addition to quantum measurements, our protocol does not use other quantum technologies such as entanglement swapping and unitary operations. A semi-honest third-party who assists two parties in implementing the protocol is assumed in our protocol. Furthermore, we use the entanglement correlations of the maximally entangled seven-qubit state and collaborative computing between parties for privacy protection, and we use quantum key distribution (QKD) to ensure the security of the cooperative computing when two parties are in different locations. What is more, we show that the security towards both outsider and insider attacks can be guaranteed.
Private comparison allows n(n ≥ 2) participants who do not trust each other to compare whether their secret data are the same, without leaking the secret data of their own. Quantum private comparison (QPC) uses quantum mechanics to accomplish the comparison. In this paper, we present a simple and effective method which can design QPC protocols based on multi-particle entangled states including the genuinely entangled five-qubit state, the generalized Brown state, the genuine six-qubit entangled state, etc. We take the Bell state and the genuinely entangled five-qubit state as examples, respectively, to present two QPC protocols, where a semi-honest third party who assists two participants in implementing the protocols is assumed. A key feature of our protocols is that quantum states are prepared by two participants rather than by the third party, which effectively prevents the third party from preparing fake quantum states, thus improving the security of the protocols. In addition, we use the entanglement properties of multi-particle entangled states and collaborative computing between participants for privacy protection, and we use QKD to ensure the security of the cooperative computing when two participants are in different locations. We show that the security of our protocols towards both outsider and insider attacks can be guaranteed.
Using the highly entangled six-qubit genuine state we present a quantum private comparison(QPC)protocol, which enables two users to compare the equality of two bits of their secrets in every round comparison with the assistance of a semi-honest third party(TP). The proposed protocol needs neither unitary operations nor quantum entanglement swapping technology, both of which may consume expensive quantum devices. Single particle measurements and Bell-basis measurements, which are easy to implement with current technologies, are employed by two users and TP in the proposed protocol, respectively. The proposed protocol can withstand all kinds of outside attacks and participant attacks. Moreover, none of information about the two users’ private secrets and the comparison result is leaked out to TP.
Quantum private comparison (QPC) is a quantum cryptographic protocol designed to enable two mutually distrustful parties to securely compare sensitive data without disclosing their private information to each other or any external entities. This study proposes a novel QPC protocol that leverages Bell states to ensure data privacy, utilizing the fundamental principles of quantum mechanics. Within this framework, two participants, each possessing a secret integer, encode the binary representation of their values using Pauli-X and Pauli-Z operators applied to quantum states transmitted from a semi-honest third party (TP). The TP, which is bound to protocol compliance and prohibited from colluding with either participant, measures the received sequences to determine the comparison result without accessing the participants’ original inputs. Theoretical analyses and simulations validate the protocol’s strong security, high efficiency, and practical feasibility in quantum computing environments. An advantage of the proposed protocol lies in its optimized utilization of Bell states, which enhances qubit efficiency and experimental practicality. Moreover, the proposed protocol outperforms several existing Bell-state-based QPC schemes in terms of efficiency.
Abstract Using the highly entangled six-qubit genuine state we present a quantum private comparison (QPC) protocol, which enables two users to compare the equality of two bits of their secrets in every round comparison with the assistance of a semi-honest third party (TP). The proposed protocol needs neither unitary operations nor quantum entanglement swapping technology, both of which may consume expensive quantum devices. Single particle measurements and Bell-basis measurements, which are easy to implement with current technologies, are employed by two users and TP in the proposed protocol, respectively. The proposed protocol can withstand all kinds of outside attacks and participant attacks. Moreover, none of information about the two users' private secrets and the comparison result is leaked out to TP.
In this paper, we introduce a two-party quantum private comparison (QPC) protocol that employs single photons as quantum resources and utilizes rotational encryption to safeguard the privacy of the inputs. This protocol enables two parties to compare their private data without disclosing any information beyond the outcome of the comparison. The participants’ private data are encoded as single photons, which are encrypted using a rotational encryption method. These encrypted single photons are then transmitted to a semi-honest third party (TP), who conducts single-particle measurements to determine if the users’ private data are equal and subsequently announces the results to the participants. By harnessing the principles of quantum mechanics, we ensure robust protection against potential eavesdropping and participant attacks. In contrast to numerous existing QPC protocols that rely on multi-qubit or d-dimensional quantum states, our method exhibits superior efficiency and practicality. Specifically, our protocol achieves a qubit efficiency of 50% by using two single photons to compare one bit of classical information, and single photons are easier to prepare than multi-qubit and d-dimensional quantum states.