Paper 2024/1262

Dilithium-Based Verifiable Timed Signature Scheme

Abstract

Verifiable Timed Signatures (VTS) are cryptographic constructs that enable obtaining a signature at a specific time in the future and provide evidence that the signature is legitimate. This framework particularly finds utility in applications such as payment channel networks, multiparty signing operations, or multiparty computation, especially within blockchain architectures. Currently, VTS schemes are based on signature algorithms such as BLS signature, Schnorr signature, and ECDSA. These signature algorithms are considered insecure against quantum attacks due to the effect of Shor's Algorithm on the discrete logarithm problem. We present a new VTS scheme called VT-Dilithium based on CRYSTALS-Dilithium Digital Signature Algorithm that has been selected as NIST's quantum-resistant digital signature standard and is considered secure against both classical and quantum attacks. Integrating Dilithium into the VTS scheme is more challenging problem due to its complex mathematical operations (i.e. polynomial multiplications, rounding operations) and large module parameters such as polynomials, polynomial vectors, and matrices. This work aims to provide a comprehensive exposition of the VT-Dilithium scheme.