We propose a new two-party quantum key agreement (QKA) protocol using five-qubit Brown states. One-way quantum transmission can be realized by merging Brown states and decoy photons randomly. The security of this protocol is shown to resist the outsider attack and participant attack over the ideal channel. Some methods are also proposed to ensure its security in noisy and lossy quantum channel. Finally, we generalize it and propose a multi-party QKA protocol based on Brown states.
We propose a new two-party quantum key agreement (QKA) protocol using five-qubit Brown states. One-way quantum transmission can be realized by merging Brown states and decoy photons randomly. The security of this protocol is shown to resist the outsider attack and participant attack over the ideal channel. Some methods are also proposed to ensure its security in noisy and lossy quantum channel. Finally, we generalize it and propose a multi-party QKA protocol based on Brown states.
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.
Recently, Cao et al. [Mod. Phys. Lett. A 34, 1950332 (2019)] presented a two-party quantum key agreement scheme using the five-qubit Brown states and the decoy protocol. They also extended their scheme to the multiparty case, and it was compared with existing works. The authors also introduced the security analysis that proves the security of their protocol against outsider and insider attacks. However, this work shows that the quantum Cao et al. [Mod. Phys. Lett. A 34, 1950332 (2019)] protocol fails to fulfill one of the most significant conditions of the quantum key agreement, which is fairness. The computed final key by the users does not have the same level of security, and the protection of users’ private data is not maintained equally. Finally, an improved version of Cao et al.’s protocol has been suggested.
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.
Quantum key agreement (QKA) is an important quantum cryptography primitive. In a QKA protocol, two or more untrusted parties can agree on an identical key in such a way that they equally influence the key and no subset can decide it alone. However, in practical QKA, the imperfections of the participant’s detectors can be exploited to compromise the security and fairness of QKA. To remove all the detector-side-channel loopholes, a measurement-device-independent multi-party QKA protocol is proposed. The protocol exploits the post-selected GHZ states to generate a secure agreement key between legitimate participants, while ensuring the fairness of key agreement. Our protocol provides a new clue for the design of practical QKA protocols.
Although there are many quantum key agreement protocols currently in existence, they cannot be merged in terms of resource utilisation, efficiency, security, and other aspects, and there are also significant differences in the nature of two and more parties. Therefore, it is necessary to design a quantum key agreement protocol that can balance efficiency and security and is suitable for multiple participants. In view of this, this paper proposes a multi-party quantum key agreement protocol based on a new coding mode of bell state: temporary session keys are negotiated between adjacent participants, and then shared keys for all participants are negotiated through the exchange, conversion, and computation of quantum resources. During the implementation of the protocol, not only can the identity of the participants be authenticated, but also the quantum resources used are single, and the quantum operations performed are simple. Moreover, efficiency is fixed and does not decrease due to the increase of participants or quantum resources. In addition, the protocol also allows participants to dynamically join and leave. In terms of security, the protocol can resist most common quantum attacks. Under the existing quantum technology, this protocol is completely feasible.
A two-party quantum key agreement protocol is proposed with five-particle entangled states and the delayed measurement technique. According to the measurement correlation property of five-particle entangled states, two participants can deduce the measurement results of each other’s initial quantum states. As a result, two parties can extract the secret keys of each other by using the publicly announced value or by performing the delayed measurement, respectively. Thus, a shared key is fairly established. Since each particle is transmitted only once in quantum channel, the protocol is congenitally free from the Trojan horse attacks. It is shown that the protocol not only is secure against both participant and outsider attacks but also has no information leakage problem. Moreover, it has high qubit efficiency.