Paper 2022/644

DiLizium 2.0: Revisiting Two-Party Crystals-Dilithium

Abstract

In previous years there has been an increased interest in designing threshold signature schemes. Most of the recent works focus on constructing threshold versions of ECDSA or Schnorr signature schemes due to their appealing usage in blockchain technologies. Additionally, a lot of research is being done on cryptographic schemes that are resistant to quantum computer attacks. In this work, we propose a new version of the two-party Dilithium signature scheme. The security of our scheme is based on the hardness of Module-LWE and Module-SIS problems. In our construction, we follow a similar logic as Damgård et al. (PKC 2021) and use an additively homomorphic commitment scheme. However, compared to them, our protocol uses signature compression techniques from the original Dilithium signature scheme which makes it closer to the version submitted to the NIST PQC competition. We focus on two-party signature schemes in the context of user authentication.

Note: This pre-print is outdated version of this paper https://link.springer.com/article/10.1007/s10791-024-09449-2 . It lacks some improvements of the final version, proper implementation and parameters. This pre-print is left unchanged from final version for historical reasons and title change.