Paper 2018/037
Weakly Secure Equivalence-Class Signatures from Standard Assumptions
Georg Fuchsbauer and Romain Gay
Abstract
Structure-preserving signatures on equivalence classes, or equivalence-class signatures for short (EQS), are signature schemes defined over bilinear groups whose messages are vectors of group elements. Signatures are perfectly randomizable and given a signature on a vector, anyone can derive a signature on any multiple of the vector; EQS thus sign projective equivalence classes. Applications of EQS include the first constant-size anonymous attribute-based credentials, efficient round-optimal blind signatures without random oracles and efficient access-control encryption. To date, the only existing instantiation of EQS is proven secure in the generic-group model. In this work we show that by relaxing the definition of unforgeability, which makes it efficiently verifiable, we can construct EQS from standard assumptions, namely the Matrix-Diffie-Hellman assumptions. We then show that our unforgeability notion is sufficient for most applications.
Metadata
- Available format(s)
-
PDF
- Publication info
- Published by the IACR in PKC 2018
- Keywords
- Structure-preserving signaturessecurity proofstandard assumptions.
- Contact author(s)
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rgay @ di ens fr
Georg Fuchsbauer @ ens fr - History
- 2018-01-08: received
- Short URL
- https://ia.cr/2018/037
- License
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CC BY
BibTeX
@misc{cryptoeprint:2018/037,
author = {Georg Fuchsbauer and Romain Gay},
title = {Weakly Secure Equivalence-Class Signatures from Standard Assumptions},
howpublished = {Cryptology {ePrint} Archive, Paper 2018/037},
year = {2018},
url = {https://eprint.iacr.org/2018/037}
}
