## CryptoDB

### Paper: Lattice-Based Blind Signatures, Revisited

Authors: Eduard Hauck , Ruhr University Bochum Eike Kiltz , Ruhr University Bochum Julian Loss , University of Maryland, College Park Ngoc Khanh Nguyen , IBM Research - Zurich DOI: http://dx.doi.org/10.1007/978-3-030-56880-1_18 (login may be required) Search ePrint Search Google CRYPTO 2020 We observe that all previously known lattice-based blind signatures schemes contain subtle flaws in their security proofs (e.g.,~Rückert, ASIACRYPT '08) or can be attacked (e.g., BLAZE by Alkadri et al., FC~'20). Motivated by this, we revisit the problem of constructing blind signatures from standard lattice assumptions. We propose a new three-round lattice-based blind signature scheme whose security can be proved, in the random oracle model, from the standard SIS assumption. Our starting point is a modified version of the insecure three-round BLAZE scheme, which itself is based Lyubashevsky's three-round identification scheme combined with a new aborting technique to reduce the correctness error. Our proof builds upon and extends the recent modular framework for blind signatures of Hauck, Kiltz, and Loss (EUROCRYPT~'19). It also introduces several new techniques to overcome the additional challenges posed by the correctness error which is inherent to all lattice-based constructions. While our construction is mostly of theoretical interest, we believe it to be an important stepping stone for future works in this area.
##### BibTeX
@inproceedings{crypto-2020-30506,
title={Lattice-Based Blind Signatures, Revisited},
publisher={Springer-Verlag},
doi={http://dx.doi.org/10.1007/978-3-030-56880-1_18},
author={Eduard Hauck and Eike Kiltz and Julian Loss and Ngoc Khanh Nguyen},
year=2020
}