International Association for Cryptologic Research

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Faster Signatures from MPC-in-the-Head

Authors:
Dung Bui , IRIF, Université Paris Cité, Paris, France
Eliana Carozza , IRIF, Université Paris Cité, Paris, France
Geoffroy Couteau , CNRS, IRIF, Université Paris Cité, Paris, France
Dahmun Goudarzi , Quarkslab
Antoine Joux , CISPA Helmholtz Center for Information Security, Saarbrücken, Germany
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Conference: ASIACRYPT 2024
Abstract: We revisit the construction of signature schemes using the MPC-in-the-head paradigm. We obtain two main contributions: – We observe that previous signatures in the MPC-in-the-head paradigm must rely on a salted version of the GGM puncturable pseudoran- dom function (PPRF) to avoid collision attacks. We design a new efficient PPRF construction that is provably secure in the multi- instance setting. The security analysis of our PPRF, in the ideal cipher model, is quite involved and forms a core technical contri- bution of our work. While previous constructions had to rely on a hash function, our construction uses only a fixed-key block cipher and is considerably more efficient as a result: we observe a 12× to 55× speed improvement for a recent signature scheme (Joux and Huth, Crypto’24). Our improved PPRF can be used to speed up many MPC-in-the-head signatures. – We introduce a new signature scheme from the regular syndrome decoding assumption, based on a new protocol for the MPC-in- the-head paradigm, which significantly reduces communication com- pared to previous works. Our scheme is conceptually simple, though its security analysis requires a delicate and nontrivial combinatorial analysis.
BibTeX
@inproceedings{asiacrypt-2024-34691,
  title={Faster Signatures from MPC-in-the-Head},
  publisher={Springer-Verlag},
  author={Dung Bui and Eliana Carozza and Geoffroy Couteau and Dahmun Goudarzi and Antoine Joux},
  year=2024
}