Abstract The key agreement protocols allow two or more users to negotiate a shared key for establishing a secure communication channel without a third trusted party in such a way that the shared key is determined by all authorized players rather than any subset of them. We propose the first real multiparty semiquantum key agreement (SQKA) protocols based on single-photons. Our protocols include only one quantum player, while the others are classical players who only need to measure and prepare states in the classical basis. We first present a symmetric three-party SQKA protocol, where two classical players can fairly negotiate a key with a quantum player by using single-photons as message carriers. Then we present an asymmetric SQKA protocol where a relatively low percentage of quantum states are used for eavesdropping detection. And we further extend them to an asymmetric multiparty SQKA protocol. Our SQKA protocols require fewer quantum resources than the previous SQKA protocols for classical players, especially without requirement of entanglement, which makes them easier to implement using current technologies. Our protocols are secure against external eavesdroppers and are fair against a minority of internal dishonest players.
Abstract The key agreement protocols allow two or more users to negotiate a shared key for establishing a secure communication channel without a third trusted party in such a way that the shared key is determined by all authorized players rather than any subset of them. We propose the first real multiparty semiquantum key agreement (SQKA) protocols based on single-photons. Our protocols include only one quantum player, while the others are classical players who only need to measure and prepare states in the classical basis. We first present a symmetric three-party SQKA protocol, where two classical players can fairly negotiate a key with a quantum player by using single-photons as message carriers. Then we present an asymmetric SQKA protocol where a relatively low percentage of quantum states are used for eavesdropping detection. And we further extend them to an asymmetric multiparty SQKA protocol. Our SQKA protocols require fewer quantum resources than the previous SQKA protocols for classical players, especially without requirement of entanglement, which makes them easier to implement using current technologies. Our protocols are secure against external eavesdroppers and are fair against a minority of internal dishonest players.
Abstract The semi-quantum key agreement (SQKA) protocol enables classical participants to complete key agreement with limited quantum capabilities. The previous semi-quantum key agreement protocols required the classical party to have the ability to measure qubits, and share a key before the protocol began. This paper proposes a SQKA protocol that allows semi-quantum participants to use single photons for key negotiation with the help of a semi-honest third party (TP). Unlike previous approaches, this protocol further reduces the quantum capability requirements for participants and eliminates the need for prior key sharing. Furthermore, through security analysis and multi-party expansion, the protocol can resist external attacks such as the intercept-resend attack, measure-resend attack, entangle-measure attack. Additionally, it can be applied to scenarios involving different numbers of participants.
Abstract In this paper, we study the properties of a set of quantum states. Based on these properties, we propose a multiparty semi-quantum key agreement (MSQKA) protocol. For the sake of clarity, we provide a three-party example to illustrate the protocol. Through rigorous security analysis, it is demonstrated that the proposed protocol can resist both inside attacks and outside attacks, which include Trojan horse attacks, measure-resend attacks, entangle-measure attacks and collective attacks. Besides, the proposed protocol achieves fairness among participants. Finally, we compare our protocol with other SQKA protocols. Compared to previous three-party and MSQKA protocols, our proposed protocol involves more classical parties, needs no external assistance and achieves relatively high key generation efficiency.
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.
As a burgeoning branch of quantum cryptography, quantum key agreement is a kind of key establishing processes where the security and fairness of the established common key should be guaranteed simultaneously. However, the difficulty on designing a qualified quantum key agreement protocol increases significantly with the increase of the number of the involved participants. Thus far, only few of the existing multiparty quantum key agreement (MQKA) protocols can really achieve security and fairness. Nevertheless, these qualified MQKA protocols are either too inefficient or too impractical. In this paper, an MQKA protocol is proposed with single photons in travelling mode. Since only one eavesdropping detection is needed in the proposed protocol, the qubit efficiency and measurement efficiency of it are higher than those of the existing ones in theory. Compared with the protocols which make use of the entangled states or multi-particle measurements, the proposed protocol is more feasible with the current technologies. Security and fairness analysis shows that the proposed protocol is not only immune to the attacks from external eavesdroppers, but also free from the attacks from internal betrayers.
Quantum key agreement (QKA) can generate a shared secret key which is equally negotiated by all the participants in the protocol. In most of the QKA protocols, all the participants require quantum capabilities. But the quantum devices are too expensive for participants. This paper proposes a mutual semi-quantum key agreement protocol which allows two parties (Alice and Bob) to negotiate a shared secret key equally. In the protocol, Alice can perform any quantum operation, but Bob is a classical participant which can only perform reflection, measurement and reorder operation. Even though Bob has fewer quantum resources, Alice and Bob have an equal contribution to the shared final key, no one can determine the shared key alone. In addition, we demonstrate the security of the proposed protocol. The analysis results show that the proposed protocol not only resists against some common attacks but also assures the fairness property. It is significant for communication participant without enough quantum devices to achieve quantum communication. The proposed protocol can be implemented with present quantum technologies.
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.