Universal Designated Verifier Signatures Research Articles

Policy-controlled signatures and their applications

In this paper, we present a new cryptographic primitive called “policy-controlled signatures”. In this notion, a signer can sign a message and attach it with some policies. Only a verifier who satisfies the policies attached can verify the authenticity of the message. This type of signature schemes has many applications, in particular to deal with sensitive data, where the signer does not want to allow anyone who is unauthorized to verify the authenticity of the messages. The notion of policy-controlled signatures resembles some similarities with designated verifier signatures, as it can also be used to designate a signature to multiple recipients. Nevertheless, we shall demonstrate that the notion of policy-controlled signatures generalize the notion of designated verifier signatures. A concrete scheme that is secure in our model is also provided. Furthermore, we also present an extension to “universal policy-controlled signature”. In this extended notion, we combine the idea of universal designated verifier signatures with policy-controlled signatures to allow more flexible delegations. We also provide a concrete scheme that is secure in our model.

Universal designated verifier transitive signatures for graph-based big data

In this paper, we propose a new type of digital signatures which is specifically designed for graph-based big data system. The properties of the proposed signatures are twofold. On one side it possesses the features of transitive signatures: One can sign a graph in such a way that, given two signatures on adjacent edges (i,j) and (j,k), anyone with public information can compute a signature on edge (i,k). The efficiency advancement (O(1) communication overhead) in transitive signatures is especially important in big data paradigm. On the other side, it is universal designated verifiable: It allows any signature holder to prove to a designated verifier that a message has been signed by the signer, but the verifier cannot convince (even sharing all secret information) any other third party of this fact. The new notion is called Universal Designated Verifier Transitive Signatures (UDVTS for short). As an integration of transitive signatures and universal designated verifier signatures, UDVTS can efficiently address privacy issues associated with dissemination of transitive signatures of graph-based big data. We further prove that our proposed design is secure in the random oracle model.

Generic constructions for universal designated-verifier signatures and identity-based signatures from standard signatures

The authors give a generic construction for universal (mutli) designated-verifier signature schemes from a large class of signature schemes, referred to as Class ℂ. The resulting schemes are efficient and have two important properties. Firstly, they are provably DV-unforgeable, non-transferable and also non-delegatable. Secondly, the signer and the designated verifier can independently choose their cryptographic settings. The authors also propose a generic construction for (hierarchical) identity-based signature schemes from any signature scheme in ℂ and prove that the construction is secure against adaptive chosen message and identity attacks. The authors discuss possible extensions of our constructions to identity-based ring signatures and identity-based designated-verifier signatures from any signature in ℂ. Finally, the authors show that it is possible to combine the above constructions to obtain signatures with combined functionalities.

NEW EXTENSIONS OF PAIRING-BASED SIGNATURES INTO UNIVERSAL (MULTI) DESIGNATED VERIFIER SIGNATURES

The concept of universal designated verifier signatures was introduced by Steinfeld, Bull, Wang and Pieprzyk at Asiacrypt 2003. These signatures can be used as standard publicly verifiable digital signatures but have an additional functionality which allows any holder of a signature to designate the signature to any desired verifier. This designated verifier can check that the message was indeed signed, but is unable to convince anyone else of this fact. We propose new efficient constructions for pairing-based short signatures. Our first scheme is based on Boneh-Boyen signatures and its security can be analyzed in the standard security model. We prove its resistance to forgery assuming the hardness of the so-called strong Diffie-Hellman problem, under the knowledge-of-exponent assumption. The second scheme is compatible with the Boneh-Lynn-Shacham signatures and is proven unforgeable, in the random oracle model, under the assumption that the computational bilinear Diffie-Hellman problem is untractable. Both schemes are designed for devices with constrained computation capabilities since the signing and the designation procedure are pairing-free. Finally, we present extensions of these schemes in the multi-user setting proposed by Desmedt in 2003.

An identity based universal designated verifier signature scheme secure in the standard model

Universal designated verifier signature was first introduced by Steinfeld, Bull, Wang and Pieprzyk in Asiacrypt 2003. In the universal designated verifier signature scheme, any holder of a signature can designate the signature to any desired designated verifier, such that only the designated verifier will believe that the signature holder holds a valid signature. In SecUbiq’05 [Zhang Fangguo, Susilo Willy, Mu Yi, Chen Xiaofeng, 2005. Identity-based universal designated verifier signatures. In: The First International Workshop on Security in Ubiquitous Computing Systems, Nagasaki, Japan, LNCS 3823. Springer-Verlag, Berlin, pp. 825–834] first extended this notion to the identity based setting and proposed two identity based universal designated verifier signature schemes. However, the security of their scheme is based on the random oracle model. Up to now, there is no provably secure identity based universal designated verifier signature scheme in the standard model. In this paper, we propose the first identity based universal designated verifier signature scheme whose security can be proven in the standard model based on the hardness of the computational Diffie–Hellman (CDH) problem.