Masayuki, A;
Groth, J;
Ohkubo, M;
Tibouchi, M;
(2014)
Unified, minimal and selectively randomizable structure-preserving signatures.
In:
Theory of Cryptography: 11th Theory of Cryptography Conference, TCC 2014, San Diego, CA, USA, February 24-26, 2014. Proceedings.
(pp. 688 - 712).
Springer: Berlin Heidelberg.
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Abstract
We construct a structure-preserving signature scheme that is selectively randomizable and works in all types of bilinear groups. We give matching lower bounds showing that our structure-preserving signature scheme is optimal with respect to both signature size and public verification key size. State of the art structure-preserving signatures in the asymmetric setting consist of 3 group elements, which is known to be optimal. Our construction preserves the signature size of 3 group elements and also at the same time minimizes the verification key size to 1 group element. Depending on the application, it is sometimes desirable to have strong unforgeability and in other situations desirable to have randomizable signatures. To get the best of both worlds, we introduce the notion of selective randomizability where the signer may for specific signatures provide randomization tokens that enable randomization. Our structure-preserving signature scheme unifies the different pairing-based settings since it can be instantiated in both symmetric and asymmetric groups. Since previously optimal structure-preserving signatures had only been constructed in asymmetric bilinear groups this closes an important gap in our knowledge. Having a unified signature scheme that works in all types of bilinear groups is not just conceptually nice but also gives a hedge against future cryptanalytic attacks. An instantiation of our signature scheme in an asymmetric bilinear group may remain secure even if cryptanalysts later discover an efficiently computable homomorphism between the source groups.
| Type: | Proceedings paper |
|---|---|
| Title: | Unified, minimal and selectively randomizable structure-preserving signatures |
| Event: | The Eleventh Theory of Cryptography Conference (TCC 2014) |
| ISBN-13: | 978-3-642-54241-1 |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1007/978-3-642-54242-8_29 |
| Publisher version: | http://dx.doi.org/10.1007/978-3-642-54242-8_29 |
| Language: | English |
| Additional information: | © IACR 2014.. This article is the final version submitted by the authors to the IACR and to Springer-Verlag on December 6, 2013. The version published by Springer-Verlag is available at http://dx.doi.org/10.1007/978-3-642-54242-8 29 |
| Keywords: | Structure-preserving signatures, automorphic signatures, selective randomizability |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Computer Science |
| URI: | https://discovery.ucl.ac.uk/id/eprint/1431076 |
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