Lattice-based Concurrent Signatures in the Standard Model
LI Bao-hong, Hongping Zhao, Jiacheng Li · Proceedings of the 4th International Conference on Computer Science and Application Engineering · 2020
We present a lattice-based concurrent signature construction as a post-quantum solution to fair exchange of digital signatures. Our construction has the following two desirable features: (1) it is adaptively secure in the standard model, that is, its security does not rely on the random oracle assumption, and (2) it achieves anonymity, a stronger security notion than ambiguity. That is, before the release of the keystone, from a third party's point of view, a signature in our construction could be generated by anyone, not just limited to two parties involved in the exchange. We obtain these results by applying a novel idea to the lattice-based signatures due to Boyen.