---
res:
bibo_abstract:
- Round-optimal blind signatures are notoriously hard to construct in the standard
model, especially in the malicious-signer model, where blindness must hold under
adversarially chosen keys. This is substantiated by several impossibility results.
The only construction that can be termed theoretically efficient, by Garg and
Gupta (Eurocrypt’14), requires complexity leveraging, inducing an exponential
security loss. We present a construction of practically efficient round-optimal
blind signatures in the standard model. It is conceptually simple and builds on
the recent structure-preserving signatures on equivalence classes (SPSEQ) from
Asiacrypt’14. While the traditional notion of blindness follows from standard
assumptions, we prove blindness under adversarially chosen keys under an interactive
variant of DDH. However, we neither require non-uniform assumptions nor complexity
leveraging. We then show how to extend our construction to partially blind signatures
and to blind signatures on message vectors, which yield a construction of one-show
anonymous credentials à la “anonymous credentials light” (CCS’13) in the standard
model. Furthermore, we give the first SPS-EQ construction under noninteractive
assumptions and show how SPS-EQ schemes imply conventional structure-preserving
signatures, which allows us to apply optimality results for the latter to SPS-EQ.@eng
bibo_authorlist:
- foaf_Person:
foaf_givenName: Georg
foaf_name: Fuchsbauer, Georg
foaf_surname: Fuchsbauer
foaf_workInfoHomepage: http://www.librecat.org/personId=46B4C3EE-F248-11E8-B48F-1D18A9856A87
- foaf_Person:
foaf_givenName: Christian
foaf_name: Hanser, Christian
foaf_surname: Hanser
- foaf_Person:
foaf_givenName: Daniel
foaf_name: Slamanig, Daniel
foaf_surname: Slamanig
bibo_doi: 10.1007/978-3-662-48000-7_12
bibo_volume: 9216
dct_date: 2015^xs_gYear
dct_language: eng
dct_publisher: Springer@
dct_title: Practical round-optimal blind signatures in the standard model@
...