Paper 2025/1673
Strong Designated Verifier Signatures with Non-delegatability from CSIDH
Abstract
Abstract. Designated verifier signature allows a signer to designate a verifier who can verify the signature. A strong designated verifier signature (SDVS) enhances privacy by ensuring that the signature itself does not leak information about the signer’s identity to anyone other than the designated verifier. Non-delegatability is a property, as it prevents the signer’s ability to generate valid signatures from being delegated to others. This property is important for SDVS applications such as e-voting. To date, post-quantum SDVS schemes with non-delegatability have been proposed. These schemes are lattice-based or hash-based schemes. While isogeny-based SDVS schemes have been proposed, none of the existing works provide a proof of non-delegatability. In this paper, we present the first isogeny-based SDVS scheme with a formal proof of non-delegatability. Our construction uses the quadratic twists of elliptic curves. The security of our scheme is proven under the commutative supersingular isogeny gap Diffie–Hellman assumption and the group action inversion problem assumption in the random oracle model.
Metadata
- Available format(s)
-
PDF
- Category
- Public-key cryptography
- Publication info
- Published elsewhere. ICISC 2025
- Keywords
- Strong designated verifier signatureNon-delegatabilityCSIDHQuadratic twist
- Contact author(s)
-
minamide @ tokyo-ct ac jp
keisuke @ is titech ac jp
tezuka m eab3 @ m isct ac jp - History
- 2025-12-15: last of 6 revisions
- 2025-09-16: received
- See all versions
- Short URL
- https://ia.cr/2025/1673
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2025/1673,
author = {Hiroki Minamide and Keisuke Tanaka and Masayuki Tezuka},
title = {Strong Designated Verifier Signatures with Non-delegatability from {CSIDH}},
howpublished = {Cryptology {ePrint} Archive, Paper 2025/1673},
year = {2025},
url = {https://eprint.iacr.org/2025/1673}
}
