Paper 2021/382

Signatures with Tight Multi-User Security from Search Assumptions

Jiaxin Pan and Magnus Ringerud

Abstract

We construct two tightly secure signature schemes based on the computational Diffie-Hellman (CDH) and factoring assumptions in the random oracle model. Our schemes are proven secure in the multi-user setting, and their security loss is constant and does not depend on the number of users or signing queries. They are the first schemes that achieve this based on standard search assumptions, as all existing schemes we are aware of are either based on stronger decisional assumptions, or proven tightly secure in the less realistic single-user setting. Under a concrete estimation, in a truly large scale, the cost of our CDH-based scheme is about half of Schnorr and DSA (in terms of signature size and running time for signing).

Metadata
Available format(s)
PDF
Category
Public-key cryptography
Publication info
Published elsewhere. ESORICS 2020
DOI
10.1007/978-3-030-59013-0_24
Keywords
Digital signaturesTight reductionMulti-user securitySearch assumption
Contact author(s)
magnus ringerud @ ntnu no
History
2021-03-22: revised
2021-03-22: received
See all versions
Short URL
https://ia.cr/2021/382
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2021/382,
      author = {Jiaxin Pan and Magnus Ringerud},
      title = {Signatures with Tight Multi-User Security from Search Assumptions},
      howpublished = {Cryptology ePrint Archive, Paper 2021/382},
      year = {2021},
      doi = {10.1007/978-3-030-59013-0_24},
      note = {\url{https://eprint.iacr.org/2021/382}},
      url = {https://eprint.iacr.org/2021/382}
}
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