Multi-party traveling-mode quantum key agreement protocols immune to collusive attack

Abstract

Owing to the disadvantages of susceptible to collusive attack in the existed multi-party quantum key agreement (MQKA) protocols with traveling mode, two secure MQKA protocols with traveling mode were proposed. In order to resist collusive attack, a trust party was introduced in the first protocol and additional random 0–1 sequence was added to the private key sequence of each participant in the second protocol. Compared to existed MQKA protocols with traveling mode, the proposed protocols have three considerable advantages. Firstly, due to the fact that only Bell state measurements and simple single-particle unitary transformation are used, the processions of the proposed protocols are simple and can be easily realized. Secondly, the proposed protocols can resist internal attack, especially collusive attack. Furthermore, the proposed protocols are superior to the existing traveling-mode MQKA protocols in efficiency. Hence, the proposed protocols have great significance both on theory and on practical application.