Are there any post-quantum blind signature algorithms? Since hash-based blind signature schemes have proven to by impossible (based on a response to this question) is this an active area of research or is it only feasible by using extraordinarily large pre-quantum algorithm keys?
This is adressed for example in Lattice-based Blind Signatures by Markus Rückert, 2008. I only had a quick glance, and it seems there is a construction for building blind signatures based on lattice problems.
But this isn't surprising, because lattice problems can be used for:
- building post-quantum encryption schemes, key exchange, signatures, etc.
- building fully-homomorphic encryption schemes. Such a system preserves a lot of algebraic structure (in contrast to OWFs), and it should be quite easy to use this to create blind signatures (which are often based on some semi-homomorphic property)