Multiparty quantum key agreement protocol secure against collusion attacks
This work addresses security vulnerabilities in quantum key agreement for multi-party communication, offering a more robust solution against collusion, though it appears incremental as it builds on existing protocols by generalizing resistance to t dishonest participants.
The paper tackles the problem of collusion attacks in multi-party quantum key agreement (MQKA) protocols, where dishonest participants can collaborate to predetermine the final key undetected, and proposes a new protocol that is secure against up to t dishonest participants, with t < N, improving fairness in key establishment.
The fairness of a secure multi-party quantum key agreement (MQKA) protocol requires that all involved parties are entirely peer entities and can equally influence the outcome of the protocol to establish a shared key wherein no one can decide the shared key alone. However, it is found that parts of the existing MQKA protocols are sensitive to collusion attacks, i.e., some of the dishonest participants can collaborate to predetermine the final key without being detected. In this paper, a multi-party QKA protocol resisting collusion attacks is proposed. Different from previous QKA protocol resisting $N-1$ coconspirators or resisting $1$ coconspirators, we investigate the general circle-type MQKA protocol which can be secure against $t$ dishonest participants' cooperation. Here, $t < N$. We hope the results of the presented paper will be helpful for further research on fair MQKA protocols.