Paper 2010/490 Original: eprint.iacr.org/2010/490 ↗

Strong designated verifier signature scheme: new definition and construction

Abstract

Recently, several strong designated verifier signature schemes have been proposed in the literature. In this paper, we first point out that such so-called strong designated verifier signature scheme is just message authentication code HMAC. Without the key property, unforgeability, for signatures, these schemes cannot enable signers to have complete controls over their signatures as demanded by Chaum and Van Antwerpen originally. No signer would use such Designated Verifier Signature schemes if he does not trust the designated verifier entirely. Then we introduce a new notion for the strong designated verifier signature scheme and its security requirements. We further propose the first strong designated verifier signature scheme based on Schnorr signature scheme, and provide a formal security proof under the DL assumption and the CDH assumption in the random oracle model. Finally, we discuss general methods to construct the strong designated verifier signature scheme.