Abstract The difficulty of quantum key agreement is to realize its security and fairness at the same time. This paper presents a new three-party quantum key agreement protocol based on continuous variable single-mode squeezed state. The three parties participating in the agreement are peer entities, making same contributions to the final key. Any one or two participants of the agreement cannot determine the shared key separately. The security analysis shows that the proposed protocol can resist both external and internal attacks.
Abstract The difficulty of quantum key agreement is to realize its security and fairness at the same time. This paper presents a new three-party quantum key agreement protocol based on continuous variable single-mode squeezed state. The three parties participating in the agreement are peer entities, making same contributions to the final key. Any one or two participants of the agreement cannot determine the shared key separately. The security analysis shows that the proposed protocol can resist both external and internal attacks.
General quantum key agreement (QKA) protocols require each participant to make the same contribution to the generation of a shared key, but this situation cannot meet the needs of government or military which require a third party only to control key agreement process. This paper proposed a continuous-variable quantum key agreement (CVQKA) protocol with multi-party Greenberg–Horne–Zeilinger (GHZ) entangled states generated by a third party. The third party prepares quantum states by sending multi-photon beam with higher emission frequency and stronger signal. Taking continuous variable as carrier, the information carried by each carrier increases, which improves the security key rate. In this paper, the third party controls but does not contribute to the final key. After receiving the states, each participant encodes his or her own key, adds a decoy state and sends it to the next participant, until receiving the quantum state that was encoded by all the participants. Then, participants can measure and calculate to get the final shared key. It shows that our protocol is easy to implement and has high efficiency. Security analysis shows that our protocol can resist collusion attacks, beam splitter attack, etc.
Abstract:In order to solve the problem that the multi-particle joint measurements are difficult to implement with the existing technology in the quantum key agreement protocols based on multi-particle entangled states , a new two-party quantum key agreement protocol was proposed based on three-particle GHZ states. Two participants in the protocol could fairly establish a shared secret key by using the measurement correlation property of three-particle GHZ states and the delayed measurement technique. Since the new protocol only used Bell measurements and single particle measurements, it was easy to achieve on the basis of the existing technology. The security analysis showed that the protocol could not only resist against participant attacks and outsider attacks, but also resist against two kinds of Trojan horse attacks. The protocol was secure not only in the noise-free quantum channel but also in the quantum noise channel. Finally, the comparison with the existed secure two-party protocols showed that the protocol also achieved higher qubit efficiency.
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.
In this study, we propose a single-state multi-party quantum key agreement (MQKA) protocol with single-particle measurement. Firstly, a single-state three-party quantum key agreement protocol with single-particle measurement is introduced, followed by a security analysis that validated its capability to resist potential internal and external attacks. Furthermore, we utilize multi-particle entangled states to present a multi-party version of the single-state multi-party quantum key agreement with single-particle measurement. In comparison to previous MQKA protocols, our approach presents the following advantages: it employs one kind of multi-particle entangled state as the quantum resource; eliminates the need for entanglement swapping techniques, unitary operations, or pre-shared keys between participants; uses only the X measurement basis and Z measurement basis; transmits fewer qubits; consumes fewer qubits; and has higher qubit efficiency.
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.