Abstract Quantum key agreement (QKA) is an important branch of quantum cryptography. Particles are easily affected by noise in quantum channel transmission, which provides a cover for eavesdropper Eve to attack maliciously and eventually leads to the protocol failure. In this paper, based on the properties of four-particle cluster states and their entanglement swapping, two authenticated two-party QKA protocols that can resist collective noise (collective-dephasing noise and collective-rotation noise) by using CZ, CNOT, and Pauli operations are designed, respectively. Besides, both parties can authenticate each other’s identities, which makes our protocol more secure. In addition, security analysis shows that these two protocols can resist various attacks from inside and outside, such as participant attacks and entangle-measure attacks.
Abstract Quantum key agreement (QKA) is an important branch of quantum cryptography. Particles are easily affected by noise in quantum channel transmission, which provides a cover for eavesdropper Eve to attack maliciously and eventually leads to the protocol failure. In this paper, based on the properties of four-particle cluster states and their entanglement swapping, two authenticated two-party QKA protocols that can resist collective noise (collective-dephasing noise and collective-rotation noise) by using CZ, CNOT, and Pauli operations are designed, respectively. Besides, both parties can authenticate each other’s identities, which makes our protocol more secure. In addition, security analysis shows that these two protocols can resist various attacks from inside and outside, such as participant attacks and entangle-measure attacks.
Abstract Quantum key agreement (QKA) is an important cryptographic primitive that plays a pivotal role in private communications. Authenticated QKA plays an important role in QKA. In this paper, we propose an authenticated multiparty QKA scheme based on 4-qubit cluster states entanglement swapping. The scheme is divided into two parts, the first part is the quantum identity authentication stage, and the second part is the QKA stage. In the quantum identity authentication stage, the participants determine that the participant communicating with them is the claimed person through mutual authentication, which can avoid the impersonation attack of the eavesdropper Eve. In the QKA phase, the participants adopt a bidirectional transmission structure with the participation of a semi-trusted third party, and based on the entanglement swapping property of the 4-qubit cluster state, the QKA is finally realized. Detailed security analysis shows that the protocol can resist a variety of internal and external attacks, such as participants attack, entangle-measure attack, and so on.
Abstract Quantum key agreement (QKA) permits participants to constitute a shared key on a quantum channel, while no participants can independently determine the shared key. However, existing Measurement-device-independent (MDI) protocols cannot resist channel noise, and noise-resistant QKA protocols cannot resist side-channel attacks caused by equipment defects. In this paper, we design a MDI-QKA protocol against collective-dephasing noise based on GHZ states. First, in our protocol, Alice and Bob prepare a certain number of GHZ states respectively, and then send two particles of each GHZ state to Charlie for bell measurement. Results are that Alice and Bob can obtain Bell states through entanglement exchange with the help of dishonest Charlie. Meanwhile ensures the transmission process noise-resisted. Then, Alice and Bob encode their key components to the particle in their hands and construct logical quantum states against collective noise through additional particles and CNOT operation to implement MDI-QKA. Compared with existing MDI-QKA protocols, our protocol uses logical quantum states during particle transfers, which makes the protocol immune to collective‑dephasing noise, and therefore improving the final key rate. Security analysis shows that our protocol can resist common insider and outsider attacks.
Based on the logic Bell states, we present two novel multi-party quantum key agreement (QKA) protocols under collective noise. The proposed protocols make full use of four-qubit logic Bell states as quantum resources and perform the novel encoding operation to generate the shared key. The security analysis shows that these two protocols can resist against both participant and outsider attacks. Furthermore, compared with the other existing multi-party QKA protocols over collective noise, our protocols have higher qubit efficiency. Finally, we perform the simulation of the relationship between efficiency and security, which is completely consistent with the conclusion of the security analysis of the protocols.
Abstract Quantum key agreement (QKA) constitutes a vital branch of quantum cryptography, referring to the collaborative establishment of a shared key among multiple participants. Among these, the three-party quantum key agreement (TPQKA) represents a specific form of QKA involving only three participants. Quantum states inevitably suffer from noise during transmission through quantum channels, which reduces the efficiency of qubits. To significantly improve the efficiency of qubits and further enhance their reliability in quantum applications, this paper proposes two TPQKA protocols based on seven-particle entangled states to provide protection against collective noise effects. In this paper, IBM Qiskit is employed to present the preparation circuit of the seven-particle entangled state, as well as the quantum circuits under two types of collective noise. In both protocols, the three parties apply a hash function to their own keys. In the particle transmission process, according to the measurement results of the particles, the three parties perform the corresponding unitary operation, and ultimately they equally negotiate the final shared key. Both protocols are robust against collective noise, and their qubit efficiency reaches 19.35%. In addition, the security analysis shows that both protocols are resistant to participant attacks and outside attacks, including intercept-resend attacks and entangle-measure attacks. This paper details the detection method of eavesdropping by eavesdroppers in collective noise through simulation, and finally presents key post-processing.
Abstract The semi-quantum key agreement (SQKA) is a combination of the ‘semi-quantum’ concept in the quantum key agreement (QKA), which aims to reduce the requirements on the quantum ability of the participants while maintaining the security of the key agreement. In this paper, two novel two-party SQKA protocols based on seven-particle entangled states and delegated quantum centers in the collective noise channels are proposed. In the two SQKA protocols, only the quantum center possesses full quantum capabilities, while other participants have only partial quantum abilities. The classical party, on the other hand, only needs to perform Z-basis measurement on the classical basis. Due to the properties of entangled states, the two SQKA protocols can resist internal and external attacks. Furthermore, this paper provides a comprehensive analysis of the security of the proposed protocols, illustrating their resilience against various forms of attacks such as eavesdropping, intercept-resend attacks, and entangle-measure attacks. The results indicate that both protocols perform well in collective noise channels while maintaining high security even under noisy conditions. Moreover, eavesdropping simulation can detect whether there is eavesdropping behavior in the communication process. Finally, a comparison with existing protocols shows that the two proposed protocols exhibit higher qubit efficiency.
In this paper, two classes of multiparticle entangled states are constructed to resist against the collective-dephasing noise and collective-rotation noise, respectively. Based on it, two new multipartite quantum key agreement protocols over the collective noise are presented. In each protocol, only one user needs to prepare the multiparticle quantum entangled state. Then, the user keeps the first qubit, and distributes each two qubits of the state to other users. In this case, all users can perform the security test and derive the shared key from the measurement outcomes of the qubits in their hands. From the security analysis, it is evident that the presented protocols are secure against the inside attack and some common outside attacks.