A Pairing Based Strong Designated Verifier Signature Scheme without Random Oracles

In this study, a novel strong designated verifier signature scheme based on bilinear pairings with provable security in the standard model is proposed, while the existing ones are secure in the random oracle model. In 2007 and 2011, two strong designated verifier signature schemes in the standard model are proposed by Huang et al. and Zhang et al., respectively; in the former, the property of privacy of the signer’s identity is not proved and the security of the latter is based on the security of a pseudorandom function. Our proposal can deal with the aforementioned drawbacks of the previous schemes. Furthermore, it satisfies non-delegatability for signature verificatio

Non-delegatable Identity-based Designated Verifier Signature

Designated verifier signature is a cryptographic primitive which allows a signer to convince a designated verifier of the validity of a statement but in the meanwhile prevents the verifier from transferring this conviction to any third party. In this work we present the \emph{first} identity-based designated verifier signature scheme that supports non-delegatability, and prove its security in the random oracle model, based on computational Diffie-Hellman assumption. Our scheme is perfectly non-transferable, and its non-delegatability follows the original definition proposed by Lipmaa et al. \cite{LipmaaWaBa05}

A Novel Strong Designated Verifier Signature Scheme without Random Oracles

In this study, a novel pairing based strong designated verifier signature scheme based on non-interactive zero knowledge proofs is proposed. The security of the proposal is presented by sequences of games without random oracles; furthermore, this scheme has a security proof for the property of privacy of the signer’s identity in comparison with the scheme proposed by Zhang et al. in 2007. In addition, this proposal compared to the scheme presented by Huang et al. in 2011 supports non-delegatability. The non-delegatability of our proposal is achieved since we do not use the common secret key shared between the signer and the designated verifier in our construction. Furthermore, if a signer delegates her signing capability which is derived from her secret key on a specific message to a third party, then, the third party cannot generate a valid designated verifier signature due to the relaxed special soundness of the non-interactive zero knowledge proof. To the best of our knowledge, this construction is the first attempt to generate a designated verifier signature scheme with non-delegatability in the standard model, while satisfying of non-delegatability property is loose

On Delegatability of Four Designated Verifier Signatures

Abstract. In a paper recently published in ICALP 2005, Lipmaa, Wang and Bao identified a new essential security property, non-delegatability, of designated verifier signature (DVS) schemes. Briefly, in a non-delegatable DVS scheme, neither a signer nor a designated verifier can delegate the signing rights to any third party T without revealing their secret keys. We show that the Susilo-Zhang-Mu identity-based strong DVS scheme, Ng-Susilo-Mu universal designated multi verifier signature scheme, the Laguillaumie-Vergnaud multi-DVS scheme and the Zhang-Furukawa-Imai universal DVS scheme are delegatable. Together with the results of Lipmaa, Wang and Bao, our results show that most of the previously proposed DVS schemes are delegatable. However, the Laguillaumie-Vergnaud and Zhang-Furukawa-Imai schemes may still be secure in practice, since there the only party who can delegate signing is the designated verifier, who may not have motivation to do so. We finish the paper with some discussion on whether the non-delegatability notion of Lipmaa, Wang and Bao is appropriate