An Efficient Strong Designated Verifier Signature Based on R-SIS Assumption

The designated verifier signature (DVS), introduced by Jakobsson et al., has the property that only the designated verifier can verify the generated signature. In order to prevent an eavesdropper to get the signature on-line before the designated verifier receives it, they also proposed strong designated verifier signature (SDVS). In this paper, according to an efficient SDVS proposed by Saeednia et al., we present a post-quantum SDVS in the random oracle model based on lattice assumption. The unforgeability is based on the hardness of the average-case hard problem R-SISq,n,m,beta, which is at least as hard as worst-case SVP gamma over ideal lattices. In addition, compared with existing lattice-based SDVS schemes, our scheme cuts by more than 50 percent repetitions and the size of signature is shorter with 256 bits security.