Cryptanalysis of a New Efficient Authenticated Multiple-Key Exchange Protocol from Bilinear Pairings

The main goal of this paper is to analyze the security of a multiple-key agreement protocol and to show that this protocol is vulnerable to forgery attack. In order to address the security weakness, a new efficient multiple-key agreement protocol is proposed. The proposed protocol is based on bilinear pairings and utilizes a novel signature scheme without one-way hash functions. In contrast to related protocols which are based on bilinear pairings, in the proposed protocol, these pairings are not utilized for the included signature scheme, but they are only used for session keys. As a result, the computational complexity of the proposed protocol is decreased by 50% compared to that of the existing protocols. Another contribution of the proposed protocol is an increase of the number of the session keys up to (n2(n + 1)2/4), for n ≥ 2 random numbers, regarding the bilinear property of the pairings. Finally, the simulation results from AVISPA tools confirm the security analysis of the proposed protocol.