Paper 2022/018

Pairing-based Accountable Subgroup Multi-signatures with Verifiable Group Setup

Ahmet Ramazan Ağırtaş, Middle East Technical University
Oğuz Yayla, Middle East Technical University
Abstract

An accountable subgroup multi-signature is a kind of multi-signature scheme in which any subgroup S of a group G of potential signers jointly sign a message m, ensuring that each member of S is accountable for the resulting signature. In this paper, we propose three novel pairing-based accountable subgroup multi-signature (ASM) schemes, which are secure against existential forgery under chosen-message attacks and computational co-Diffie-Hellman assumption. In the first one, we use Feldman’s verifiable secret sharing scheme as an implicit authentication and proof-of-possession for setting up group G. In the second one, the members participating in authentication are decided by the subgroup. In the third one, we consider a designated combiner managing the authentication process. All schemes we propose here require fewer computations in the signature generation, signature aggregation, and verification phases than the pairing-based ASM scheme proposed by Boneh, Drijvers, and Neven. Moreover, our first and third ones solve the open problem of constructing an ASM scheme in which the subgroup of signers is unknown before the signature generation. Besides, we give a method of eliminating the combiner in case of knowing the subgroup of signers in advance. Further, we extend our proposed schemes to aggregated versions. For accountable subgroup multi-signatures, aggregated versions of our proposed schemes output an aggregated signature with the size of a single group () element and require pairings in aggregated signature verification. In contrast, the partially aggregated ASM scheme of Boneh, Drijvers, and Neven gives an aggregated signature with the size of group elements and requires pairings in aggregated signature verification.

Metadata
Available format(s)
PDF
Category
Public-key cryptography
Publication info
Preprint.
Keywords
multi-signatureaccountable subgroup multi-signaturepairing-based cryptography
Contact author(s)
agirtas ramazan @ metu edu tr
oguz @ metu edu tr
History
2023-05-16: last of 3 revisions
2022-01-08: received
See all versions
Short URL
https://ia.cr/2022/018
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2022/018,
      author = {Ahmet Ramazan Ağırtaş and Oğuz Yayla},
      title = {Pairing-based Accountable Subgroup Multi-signatures with Verifiable Group Setup},
      howpublished = {Cryptology {ePrint} Archive, Paper 2022/018},
      year = {2022},
      url = {https://eprint.iacr.org/2022/018}
}
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