Abstract Based on the decoherence‐free states, two multi‐party semi‐quantum private comparison protocols are proposed to counteract collective noises. One can resist the collective‐dephasing noise well, and the other can resist the collective‐rotation noise. With the assistance of a semi‐honest third party (TP), multiple classical participants with restricted quantum abilities can compare their secret information by performing the proposed protocols once. It is manifested that the proposed protocols can resist both external attacks and internal attacks. Additionally, the operations in the multi‐party semi‐quantum private comparison protocols are simulated on the IBM Quantum Experience.
Abstract Based on the decoherence‐free states, two multi‐party semi‐quantum private comparison protocols are proposed to counteract collective noises. One can resist the collective‐dephasing noise well, and the other can resist the collective‐rotation noise. With the assistance of a semi‐honest third party (TP), multiple classical participants with restricted quantum abilities can compare their secret information by performing the proposed protocols once. It is manifested that the proposed protocols can resist both external attacks and internal attacks. Additionally, the operations in the multi‐party semi‐quantum private comparison protocols are simulated on the IBM Quantum Experience.
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.
Abstract In this paper, we propose a novel semiquantum private comparison (SQPC) protocol based on Bell states, which enables one quantum user and one classical user to compare the equality of their private inputs with the help of a semi-honest quantum third party (TP). TP is assumed to be semi-honest in the sense that she may take all possible attacks to steal users’ private inputs except conspiring with anyone. The security analysis validates that our protocol can resist not only the attacks from internal participants but also the attacks from an external eavesdropper. Besides, our protocol only asks TP to perform Bell basis measurements but does not need quantum entanglement swapping; and it releases the classical user from conducting quantum measurements and having a quantum memory. Moreover, our protocol can take advantage over previous SQPC protocols based on Bell states in qubit efficiency. Finally, our protocol can be generalized into its counterpart of the collective-dephasing noise quantum channel.
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.
Abstract Semi-quantum secret sharing facilitates the sharing of private data between quantum users and ‘classical’ users with limited quantum capabilities, thereby lowering the barrier to utilizing quantum technology. However, most current semi-quantum secret sharing protocols are confined to ideal environments and two-party scenarios. In this paper, we design two collective noise-resistant multi-party semi-quantum secret sharing protocols based on decoherence-free states to address potential noise interference during transmission. These protocols use decoherence-free states as information carriers for data interaction and exhibit strong resilience to both internal and external threats. We also conduct simulation experiments using IBM Qiskit to verify the stability and feasibility of the protocols in the noisy environments. The results of these experiments underscore the robustness of the protocols, particularly in the presence of collective noise. Compared with previous related protocols, our protocols have advantages in noise resistance and applicability to multi-party scenarios. Therefore, the proposed protocols may be more in line with the secret sharing needs of actual environments.
Abstract Based on Bell states, a new semi-quantum private comparison protocol is proposed that enables two classical users to securely compare the equality of their private information with the aid of a semi-honest third party. Different from the existing semi-quantum private comparison protocols, the two classical participants in the presented protocol do not need to measure and prepare any quantum state, which not only reduces the consumption of quantum devices, but also greatly improves the feasibility of the protocol. Performing different unitary operations on the received particles, classical users can securely compare their secret information. Besides, the devised protocol has higher qubit efficiency than the other similar counterparts, since participants can compare a two-bit privacy each time with one qubit. Meanwhile, after completing the comparison process, all Bell states could be reused since they still retain the corresponding entanglement property, which greatly facilitates the recycle of quantum resources. Security analyses indicate that the designed scheme is secure against external attack and internal attack. Moreover, the operations involved in our scheme are simulated on the IBM Quantum Experience to demonstrate the effectiveness and security of our scheme.
Private comparison is a primitive for many cryptographic tasks, and recently several schemes for the quantum private comparison (QPC) have been proposed, where two users can compare the equality of their secrets with the help of a semi-honest third party (TP) without knowing each other’s secret and without disclosing the same to the TP. In the existing schemes, secrecy is obtained by using conjugate coding, and considering all participants as quantum users who can perform measurement(s) and/or create states in basis other than computational basis. In contrast, here we propose two new protocols for QPC, first of which does not use conjugate coding (uses orthogonal states only) and the second one allows the users other than TP to be classical whose activities are restricted to either reflecting a quantum state or measuring it in computational basis. Further, the performance of the protocols is evaluated under various noise models.