Pairing-Free Blind Signatures from CDH Assumptions

Rutchathon Chairattana-Apirom; Stefano Tessaro; Chenzhi Zhu

Paper 2023/1780

Pairing-Free Blind Signatures from CDH Assumptions

Rutchathon Chairattana-Apirom

, University of Washington

Stefano Tessaro

, University of Washington

Chenzhi Zhu

, University of Washington

Abstract

This paper presents new blind signatures for which concurrent security, in the random oracle model, can be proved from variants of the computational Diffie-Hellman (CDH) assumption in pairing-free groups without relying on the algebraic group model (AGM). With the exception of careful instantiations of generic non-black box techniques following Fischlin's paradigm (CRYPTO '06), prior works without the AGM in the pairing-free regime have only managed to prove security for a-priori bounded concurrency. Our most efficient constructions rely on the chosen-target CDH assumption, which has been used to prove security of Blind BLS by Boldyreva (PKC '03), and can be seen as blind versions of signatures by Goh and Jarecki (EUROCRYPT '03) and Chevallier-Mames (CRYPTO'05). We also give a less efficient scheme with security based on (plain) CDH which builds on top of a natural pairing-free variant of Rai-Choo (Hanzlik, Loss, and Wagner, EUROCRYPT '23). Our schemes have signing protocols that consist of four (in order to achieve regular unforgeability) or five moves (for strong unforgeability). The blindness of our schemes is either computational (assuming the hardness of the discrete logarithm problem), or statistical in the random oracle model.

Metadata

Available format(s): PDF
Category: Public-key cryptography
Publication info: Preprint.
Keywords: Blind Signatures CDH Assumption
Contact author(s): rchairat @ cs washington edu
tessaro @ cs washington edu
zhucz20 @ cs washington edu
History: 2023-11-20: approved; 2023-11-17: received; See all versions
Short URL: https://ia.cr/2023/1780
License: CC BY

BibTeX

@misc{cryptoeprint:2023/1780,
      author = {Rutchathon Chairattana-Apirom and Stefano Tessaro and Chenzhi Zhu},
      title = {Pairing-Free Blind Signatures from CDH Assumptions},
      howpublished = {Cryptology ePrint Archive, Paper 2023/1780},
      year = {2023},
      note = {\url{https://eprint.iacr.org/2023/1780}},
      url = {https://eprint.iacr.org/2023/1780}
}