CryptoDB
Cecilia Boschini
Publications
Year
Venue
Title
2022
CRYPTO
MuSig-L: Lattice-Based Multi-Signature With Single-Round Online Phase
📺
Abstract
Multi-signatures are protocols that allow a group of signers to jointly produce a single signature on the same message. In recent years, a number of practical multi-signature schemes have been proposed in the discrete-log setting, such as MuSigT (CRYPTO'21) and DWMS (CRYPTO'21).
The main technical challenge in constructing a multi-signature scheme is to achieve a set of several desirable properties, such as (1) security in the plain public-key (PPK) model, (2) concurrent security, (3) low online round complexity, and (4) key aggregation. However, previous lattice-based, post-quantum counterparts to Schnorr multi-signatures fail to satisfy these properties.
In this paper, we introduce MuSigL, a lattice-based multi-signature scheme simultaneously achieving these design goals for the first time.
Unlike the recent, round-efficient proposal of Damgård et al. (PKC'21), which had to rely on lattice-based trapdoor commitments, we do not require any additional primitive in the protocol, while being able to prove security from the standard module-SIS and LWE assumptions.
The resulting output signature of our scheme therefore looks closer to the usual Fiat--Shamir-with-abort signatures.
Coauthors
- Akira Takahashi (1)
- Mehdi Tibouchi (1)