A New Code-Based Identity-Based Signature Scheme from the Ternary Large-Weight SDP

Identity-based cryptography introduced by Shamir (Crypto’84) has seen many advances through the years. In the context of post-quantum identity-based schemes, most of the efficient designs are based on lattices. In this work, we propose an identity-based identification (IBI) scheme and an identity-based signature (IBS) scheme based on codes. Our design combines the hash-and-sign signature scheme, Wave, with a Stern-like signature scheme, BGKM-SIG1, instantiated over a ternary field using the large-weight Syndrome Decoding Problem (SDP). Our scheme significantly outperforms existing code-based identity-based signature constructions.