Compact Lattice Signatures.

Lattice-based signature schemes have seen many improvements in the past few years with recent attempts (Güneysu et al., 2012; Ducas et al., 2013; Ducas et al., 2014; Lyubashevsky, 2016; Ducas et al., 2017) to bring lattice-based signature schemes at par with the traditional number-theoretic signature schemes. However, the trade-off between the signature size and the key size, time for a signature generation, and the practical and provable security is not necessarily the optimal. We propose a compact lattice-based signature scheme with key-size and signatures of order n, where n is the dimension of the lattice. The proposed signature scheme has faster algorithms for key generation, signing, and verification than the existing schemes. The proposed scheme is simple and is competitive with the other post-quantum signature schemes.