Paper 2026/943

Optimized G+G Signature

Shuoqu Jian, College of Science, National University of Defense Technology

Longjiang Qu, College of Science, National University of Defense Technology

Abstract

At ASIACRYPT 2023, Devevey, Passelègue and Stehlé proposed the G+G signature, which is designed based on the Fiat-Shamir transform without rejection sampling technique. However, the optimization of the G+G signature have not been studied as extensively as those of Lyubashevsky-type signatures. The contribution of this work is the integration of the Asymmetric Learning with Errors (ALWE) problem into the key generation phase of the G+G signature. We present a more precise estimation method for the largest singular value of the secret key and introduce a new non-spherical Gaussian distribution to characterize the signature distribution. Experimental results demonstrate that, under parameters ensuring the same security level, our optimized G+G variant reduces the signature size by approximately 25%.

@misc{cryptoeprint:2026/943,
      author = {Renjie Jin and Shuoqu Jian and Longjiang Qu},
      title = {Optimized G+G Signature},
      howpublished = {Cryptology {ePrint} Archive, Paper 2026/943},
      year = {2026},
      url = {https://eprint.iacr.org/2026/943}
}