An Improved Efficient Secret Handshakes Scheme with Unlinkability

Recently, an unlinkable secret handshakes scheme was proposed by Huang and Cao who claimed their scheme achieved affiliation-hiding, unlinkability and meanwhile was more efficient than the previous ones. However, Su, Youn and Park pointed out that the scheme is insecure due to some design flaw, respectively. In this paper, inspired by the security review of their work, we modify Huang-Cao scheme and propose an improved secret handshakes scheme with unlinkability. Our proposal not only conquers the security flaw in Huang-Cao scheme but also is more efficient than the previous schemes.