Paper 2016/662

Practical Round-Optimal Blind Signatures in the Standard Model from Weaker Assumptions

Georg Fuchsbauer, Christian Hanser, Chethan Kamath, and Daniel Slamanig


At Crypto'15 Fuchsbauer, Hanser and Slamanig (FHS) presented the first standard-model construction of efficient round-optimal blind signatures that does not require complexity leveraging. It is conceptually simple and builds on the primitive of structure-preserving signatures on equivalence classes (SPS-EQ). FHS prove the unforgeability of their scheme assuming EUF-CMA security of the SPS-EQ scheme and hardness of a version of the DH inversion problem. Blindness under adversarially chosen keys is proven under an interactive variant of the DDH assumption. We propose a variant of their scheme whose blindness can be proven under a non-interactive assumption, namely a variant of the bilinear DDH assumption. We moreover prove its unforgeability assuming only unforgeability of the underlying SPS-EQ but no additional assumptions as needed for the FHS scheme.

Available format(s)
Cryptographic protocols
Publication info
Published elsewhere. Major revision. SCN 2016
Blind SignaturesStandard ModelSPS-EQ
Contact author(s)
christian hanser @ iaik tugraz at
2016-06-28: received
Short URL
Creative Commons Attribution


      author = {Georg Fuchsbauer and Christian Hanser and Chethan Kamath and Daniel Slamanig},
      title = {Practical Round-Optimal Blind Signatures in the Standard Model from Weaker Assumptions},
      howpublished = {Cryptology ePrint Archive, Paper 2016/662},
      year = {2016},
      note = {\url{}},
      url = {}
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