A Tree-type Multiparty Quantum Key Agreement Protocol Against Collusive Attacks

Multiparty quantum key agreement (MQKA) requires sharing a secure and fair key among participants. However, several malicious participants may collude together to steal the privacy of honest participants or determine the shared key, privately. In this work, we propose a tree-type MQKA protocol against collusive attacks, in which the entanglement swapping technology of multi-particle entangled states is used to construct the shared key. Compared with the previous MQKA protocols against collusive attacks, our scheme consumes fewer qubits and only needs to transmit quantum states once, which significantly reduces the consumption of quantum resources.