Short Lee-Metric Code-Based Signature

Since the first Lee-metric signature scheme FuLeeca has been broken, it is challenging to construct a Lee-metric signature scheme. In this paper, we construct a new Lee-metric code-based signature scheme, called LM-QCS. The new signature scheme is based on quasi-cyclic codes and is constructed via the Fiat-Shamir framework without aborts. It uses ephemeral secret keys to generate a signature, rather than relying solely on a fixed secret key. Therefore, the new signature scheme is like a one-time signature scheme. We present thorough security analyses against various possible attacks. Based on the security analysis, the public key size and signature size of the LM-QCS signature scheme are 1123 bytes and 2106 bytes respectively to achieve 128-bit classical security level.