New conference key agreement protocol with user anonymity

In 2003, Yang et al. presented a conference key distribution system that was intended to provide user anonymity. Subsequently, Lin et al. pointed out a security flaw in Yang et al.'s scheme based on solving linear equations and proposed a modified scheme. Accordingly, the current paper reviews the schemes proposed by Yang et al. and Lin et al., highlights the weakness in both schemes, and then proposes a new conference key agreement scheme with user anonymity.