Efficient strong designated verifier proxy signature scheme with low cost

Designated verifier proxy signature is a special proxy signature where only the designated verifier can verify the validity. So far, numerous strong designated verifier proxy signature (DVPST) schemes have been proposed. However, many of them have been pointed out to be vulnerable to the forgery attack or have high computational cost. In 2012, Lin et al. proposed a highly efficient and strong DVPST scheme in the random oracle model. However, in this paper, we address that Lin et al.´s strong DVPST scheme does not satisfy the unforgeability. In order to overcome this problem, based on the hardness of discrete logarithm problem, we present a new strong DVPST scheme. We also make a detail analysis and comparison on the security and efficiency with other related schemes including Lin et al.´s scheme. The analysis shows that our scheme not only has excellent performance in terms of computation cost and communication cost but also possesses unforgeability, non-transferability and privacy of signer´s identity.