An Improved Compression Technique for Signatures Based on Learning with Errors

We present a new approach to the compression technique of Lyubashevsky et al. [18, 14] for lattice-based signatures based on learning with errors (LWE). Our ideas seem to be particularly suitable for signature schemes whose security, in the random oracle model, is based on standard worst-case computational assumptions. Our signatures are shorter than any previous proposal for provably-secure signatures based on standard lattice problems: at the 128-bit level we improve signature size from (more than) 16500 bits to around 9000 to 12000 bits. This is the full version of the paper. The conference version was published at CT-RSA 2014.