The Wonderful World of Dilithium (aka ML-DSA) and The Fiat Shamir Method

When Zero Knowledge Proof Methods Become Digital Signatures

Did you know that Zero Knowledge Proof (ZKP) methods are now being used for Digital Signatures? Well, I’ll explain in this article and where we will meet two of the core builders of scaling ZKP methods into a quantum robust world of digital signatures: Vadim Lyubashevsky and Chris Peikert.

Introduction

Over the past year, I’ve had some great talks with the people who built the foundation of lattice-based cryptography. These include Vadim Lyubashevsky and Chris Peiker. Neither of them actually knew how significant their work was going to be, but in the end, it is now generally lattice-based methods that are going to be used to replace our existing RSA and ECC (Elliptic Curve Cryptography) methods. This includes ML-KEM (aka CRYSTALS Kyber — FIPS 203), ML-DSA (aka Dilithium — FIPS 204) and FN-DSA (aka FALCON — FIPS 206). These methods are generally faster than the other PQC techniques and generally have manageable size keys.

CRYSTALS Dilithium uses lattice-based Fiat-Shamir schemes, and produces one of the smallest signatures of all the post-quantum methods, and with relatively small public and private key sizes. The three main implements for…