CryptoDB
Tanuki: New Frameworks for (Concurrently Secure) Blind Signatures from Post-Quantum Groups Actions
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| Conference: | ASIACRYPT 2025 |
| Abstract: | Blind signatures are fundamental cryptographic primitives enabling privacy-preserving authentication and have seen renewed interest in the post-quantum literature. Existing efficient constructions predominantly rely on Fischlin’s generic paradigm instantiated over lattice assumptions, while blinding techniques for $\Sigma$-protocol-based blind signatures remain sparse beyond lattices. Moreover, achieving provable concurrent security under polynomially many sessions has been a longstanding open challenge for this approach in the post-quantum literature as evidenced by the recent attacks in EC’24 and PKC’24. This work broadens the landscape of post-quantum blind signatures by introducing novel techniques and proposing four frameworks based on general cryptographic group actions, without requiring commutativity. Our constructions admit instantiations under diverse post-quantum assumptions, including CSIDH (isogeny-based), LESS (code-based, NIST round-two), and more. These frameworks offer flexible trade-offs in assumptions (from interactive one-more to the standard inversion problem) and key/signature sizes, and culminate in a construction that achieves security under polynomially many concurrent sessions. This enables the first efficient blind signatures from isogenies and codes with provable concurrent security with 4.5 and 64.7 KB respectively. We also outline several directions for optimization and further instantiations for future work. |
BibTeX
@inproceedings{asiacrypt-2025-36020,
title={Tanuki: New Frameworks for (Concurrently Secure) Blind Signatures from Post-Quantum Groups Actions},
publisher={Springer-Verlag},
author={Lucjan Hanzlik and Yi-Fu Lai and Marzio Mula and Eugenio Paracucchi and Daniel Slamanig and Gang Tang},
year=2025
}