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Practical Blind Signatures in Pairing-Free Groups
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| Conference: | ASIACRYPT 2024 |
| Abstract: | Blind signatures have garnered significant attention in recent years, with several efficient constructions in the random oracle model relying on well-understood assumptions. However, this progress does not apply to pairing-free cyclic groups: fully secure constructions over cyclic groups rely on pairings, remain inefficient, or depend on the algebraic group model or strong interactive assumptions. To address this gap, Chairattana-Apirom, Tessaro, and Zhu (CTZ, Crypto 2024) proposed a new scheme based on the CDH assumption. Unfortunately, their construction results in large signatures and high communication complexity. In this work, we propose a new blind signature construction in the random oracle model that significantly improves upon the CTZ scheme. Compared to CTZ, our scheme reduces communication complexity by a factor of more than 10 and decreases the signature size by a factor of more than 45, achieving a compact signature size of only 224~Bytes. The security of our scheme is based on the DDH assumption over pairing-free cyclic groups, and we show how to generalize it to the partially blind setting. |
BibTeX
@inproceedings{asiacrypt-2024-34504,
title={Practical Blind Signatures in Pairing-Free Groups},
publisher={Springer-Verlag},
author={Michael Klooß and Michael Reichle and Benedikt Wagner},
year=2024
}