Cryptanalysis of Lee et al.’s authenticated group key agreement
Wei Yuan, Liang Qing Hu, Hongtu Li, Jianfeng Chu · Procedia Engineering · 2011
Authenticated key agreement protocols are to authenticate the users who will start a conversation and establish a common session key. In 2009, Cheng-chi Lee et al. proposed a new authenticated group key agreement based on a novel bilinear pairing to provide integrity of the transmitted messages. In this paper, we show that Cheng-chi Lee et al.’s protocol can only ensure the validity between the second step and the third step, and the intermediate message between the first step and the second step can be disturbed by attackers. That is, Cheng-chi Lee et al.’s protocol doesn’t achieve their goal.