Sharper Ring-LWE Signatures

We present TESLA] (pronounced “Tesla Sharp”), a digital signature scheme based on the R-LWE assumption that continues a recent line of proposals of lattice-based digital signature schemes originating in work by Lyubashevsky as well as by Bai and Galbraith. It improves upon all of its predecessors in that it attains much faster key pair generation, signing, and verification, outperforming most (conventional or lattice-based) signature schemes on modern processors. We propose a selection of concrete parameter sets, including a high-security instance that aims at achieving post-quantum security. Based on these parameters, we present a full-fledged software implementation protected against timing and cache attacks that supports two scheme variants: one providing 128 bits of classical security and another providing 128 bits of post-quantum security.