Tweed: Adaptively Secure Lattice-Based Two-Round Threshold Signatures

Kaijie Jiang; Stefano Tessaro; Hoeteck Wee; Chenzhi Zhu

Paper 2026/417

Tweed: Adaptively Secure Lattice-Based Two-Round Threshold Signatures

Kaijie Jiang

, Tsinghua University

Stefano Tessaro

, University of Washington

Hoeteck Wee, NTT Research

Chenzhi Zhu

, NTT Research

Abstract

This paper gives the first lattice-based two-round threshold signature scheme that tolerates the adaptive corruption of up to $T -1$ out of $N$ signers. Our construction is based on the MLWE and MSIS assumptions. We substantially improve upon the only existing adaptively secure lattice-based construction, recently given by Katsumata, Reichle, and Takemure (CRYPTO '24), which requires five rounds.

Metadata

Available format(s): PDF
Category: Public-key cryptography
Publication info: A minor revision of an IACR publication in EUROCRYPT 2026
Contact author(s): kjj101110 @ gmail com
tessaro @ cs washington edu
wee @ di ens fr
zhucz20 @ cs washington edu
History: 2026-03-03: approved; 2026-03-02: received; See all versions
Short URL: https://ia.cr/2026/417
License: CC BY

BibTeX

@misc{cryptoeprint:2026/417,
      author = {Kaijie Jiang and Stefano Tessaro and Hoeteck Wee and Chenzhi Zhu},
      title = {Tweed: Adaptively Secure Lattice-Based Two-Round Threshold Signatures},
      howpublished = {Cryptology {ePrint} Archive, Paper 2026/417},
      year = {2026},
      url = {https://eprint.iacr.org/2026/417}
}