BlindOR - an Efficient Lattice-Based Blind Signature Scheme from OR-Proofs.

An OR-proof is a protocol that enables a user to prove the possession of a witness for one of two (or more) statements, without revealing which one. Abe and Okamoto (CRYPTO 2000) used this technique to build a partially blind signature scheme whose security is based on the hardness of the discrete logarithm problem. Inspired by their approach, we present BlindOR, an efficient blind signature scheme from OR-proofs based on lattices over modules. Using OR-proofs allows us to reduce the security of our scheme from the MLWE and MSIS problems, yielding a much more efficient solution compared to previous works.