### Repudiable Ring Signature: Stronger Security and Logarithmic-Size

Hao Lin and Mingqiang Wang

##### Abstract

Ring signatures allow a person to generate a signature on behalf of an ad hoc group, and can hide the true identity of the signer among the group. Repudiable ring signatures are the more strongly defined ring signatures, which can allow every non-signer to prove to others that the signature was not generated by himself. This paper has two main areas of focus. First, we propose a new requirement for repudiable ring signatures, which is that no one can forge a valid repudiation for others. Second, as a breakthrough, we present the first logarithmic-size repudiable ring signatures which do not rely on a trusted setup or the random oracle model. Specifically, our scheme can be instantiated from standard assumptions and the size of signatures and repudiations only grows logarithmically in the number of ring members. Besides, our scheme also provides a new construction of logarithmic-size standard ring signatures.

Available format(s)
Category
Public-key cryptography
Publication info
Preprint. MINOR revision.
Keywords
ring signaturesrepudiable ring signaturesstandard model
Contact author(s)
lhao17 @ mail sdu edu cn
History
2020-05-30: revised
See all versions
Short URL
https://ia.cr/2019/1269

CC BY

BibTeX

@misc{cryptoeprint:2019/1269,
author = {Hao Lin and Mingqiang Wang},
title = {Repudiable Ring Signature: Stronger Security and Logarithmic-Size},
howpublished = {Cryptology ePrint Archive, Paper 2019/1269},
year = {2019},
note = {\url{https://eprint.iacr.org/2019/1269}},
url = {https://eprint.iacr.org/2019/1269}
}

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