Paper 2026/226

Round-Optimal Identity-Based Blind Signature from Module Lattice Assumptions

Mrittika Nandi, Indian Institute of Science Education and Research Bhopal

Shashank Singh, Indian Institute of Science Education and Research Bhopal

Abstract

This work presents a round optimal identity-based blind signature scheme based on module lattices. Our construction extends Fischlin's two-round blind signature framework [CRYPTO'06] to the identity-based setting. The construction uses the GPV signature scheme based on Micciancio and Peikert's G-trapdoor techniques and NIZK proofs [CRYPTO'22] in the random oracle model. The scheme is secure under the MLWE and MSIS assumptions. The optimised parameters are also provided targeting $128$-bit security. To the best of our knowledge, this scheme is the first-round optimal identity-based blind signature scheme whose security relies on module lattice problems.

@misc{cryptoeprint:2026/226,
      author = {Arup Mazumder and Mrittika Nandi and Shashank Singh},
      title = {Round-Optimal Identity-Based Blind Signature from Module Lattice Assumptions},
      howpublished = {Cryptology {ePrint} Archive, Paper 2026/226},
      year = {2026},
      url = {https://eprint.iacr.org/2026/226}
}