Paper 2025/2097

Hash-Based Blind Signatures: First Steps

Hugo Louiso, Université de Bordeaux

Abstract

Hash-based signatures are a strong candidate for post-quantum scenarios requiring authentication and integrity. Their security relies only on (well-studied) properties of hash functions, so they may be thought as being more robust than other schemes that (today) resist quantum attacks, like those based on lattices, coding or isogenies. Recent works also study hash-based signature schemes with additional properties, such as group, ring, threshold, or aggregate signature schemes. In this work, we do the same for the important case of blind signatures. We describe a secure (in the programmable random oracle model) modification of Fischlin's generic construction of blind signatures that can be instantiated with different hash-based protocols. As a result, we obtain the first blind signature schemes whose security relies only on the collision resistance of hash functions. Finally, as a proof of concept, we have implemented one (highly non-optimized) of the possible instantiations.

Note: Added references to recent/concurrent very related work, improved presentation and formalism

@misc{cryptoeprint:2025/2097,
      author = {Javier Herranz and Hugo Louiso},
      title = {Hash-Based Blind Signatures: First Steps},
      howpublished = {Cryptology {ePrint} Archive, Paper 2025/2097},
      year = {2025},
      url = {https://eprint.iacr.org/2025/2097}
}