An efficient threshold shared verification signature scheme and its application

A new threshold shared verification signature scheme based on discrete logarithm is proposed, which is the integration of ElGamal signature scheme and Shamir threshold secret sharing scheme. In this scheme, any t of n verifiers can verify the validity of the signature and any t-1 or fewer verifiers can not verify the validity of the signature. Forging signatures in the proposed scheme is provably equivalent to forging ElGamal signatures. As compared to previous scheme, our scheme is more efficient for signature generation. Finally a new shared password authentication scheme based on the proposed threshold shared verification signature scheme is proposed.