Ring Signatures Based on Subfield Bilinear Collision Problem via MPC-in-the-Head

16 pages•Published: August 6, 2026

Hiroaki Anada, Masayuki Fukumitsu and Shingo Hasegawa

Abstract

We propose a ring signature scheme whose unforgeability is based on the assumption that the subfield bilinear collision (SBC) problem is hard. The SBC problem was introduced at CRYPTO 2024, which is related to a bilinear form over a finite field with a symmetric solution in its subfield. It is considered to be hard even against the power of quantum computers, and hence our ring signature scheme is expected to be a post-quantum one. The size of our ring signature is linear to the size of a ring, but shorter than a naive approach that uses the OR-proof technique. Concretely, when the size of a ring is 32, 128-bit quantum security is attained with the signature length being about 68 KB.

Keyphrases: anonymity, mpc in the head, post quantum security, ring signatures, subfield bilinear collision problem, unforgeability, zero knowledge proofs

In: Tung-Tso Tsai, Huy Kang Kim, Yujue Wang and Akira Yamada (editors). Proceedings of The 21st Asia Joint Conference on Information Security, vol 111, pages 79-94.

Links:	https://easychair.org/publications/paper/HN7h
	https://doi.org/10.29007/7mz8

BibTeX entry

@inproceedings{AsiaJCIS2026:Ring_Signatures_Based_Subfield,
  author    = {Hiroaki Anada and Masayuki Fukumitsu and Shingo Hasegawa},
  title     = {Ring Signatures Based on Subfield Bilinear Collision Problem via MPC-in-the-Head},
  booktitle = {Proceedings of The 21st Asia Joint Conference on Information Security},
  editor    = {Tung-Tso Tsai and Huy Kang Kim and Yujue Wang and Akira Yamada},
  series    = {EPiC Series in Computing},
  volume    = {111},
  publisher = {EasyChair},
  bibsource = {EasyChair, https://easychair.org},
  issn      = {2398-7340},
  url       = {/publications/paper/HN7h},
  doi       = {10.29007/7mz8},
  pages     = {79-94},
  year      = {2026}}

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