**Abstract:** All known round optimal (i.e., two-move) blind signature schemes either need a
common reference string, rely on random oracles, or assume the hardness of some
interactive assumption. At Eurocrypt 2010, Fischlin and Schröder showed that a
broad class of three-move blind signature scheme cannot be instantiated in the
standard model based on any non-interactive assumption. This puts forward the
question if round optimal blind signature schemes exist in the standard model.
Here, we give a positive answer presenting the first round optimal blind signature
scheme that is secure in the standard model without any setup assumptions. Our
solution does not need interactive assumptions.

Merged into *Schröder, Unruh, Garg, Rao, Sahai, Round Optimal Blind Signatures, 2011*

**Permalink:** http://www.ut.ee/~unruh/publications/2roundbs-orig.html