Paper 2026/1094
Asymmetric Message Franking in the Plain Model: Generic and Efficient Constructions
, National Institute of Advanced Industrial Science and TechnologyAbstract
Asymmetric Message Franking (AMF), proposed by Tyagi et al. at Crypto’19, is a sort of signature scheme that aims to provide privacy-preserving content moderation in secure messaging applications. In this work, we present the first generic construction of AMF using a public-key encryption scheme, a signature scheme, and a ZAP proof system for NP languages. This construction yields the first AMF scheme provably secure in the plain model from standard assumptions, and has tight security. To improve the efficiency of AMF in the plain model, we build a concrete scheme from asymmetric pairing groups based on our idea for the generic construction. It achieves a signature size of 47 group elements, which is significantly smaller than an instantiation of the generic construction. Also, we provide a variant of the generic construction that yields a post-quantum secure AMF scheme in the plain model from a polynomially hard LWE assumption, demonstrating its feasibility.
Metadata
- Available format(s)
-
PDF
- Category
- Public-key cryptography
- Publication info
- A major revision of an IACR publication in CRYPTO 2026
- DOI
- 10.1007/978-3-032-35428-0_13
- Keywords
- Asymmetric Message FrankingSecure MessagingGeneric ConstructionPlain Model
- Contact author(s)
-
milan gonzalez-thauvin @ inf ethz ch
keitaro hashimoto @ aist go jp - History
- 2026-08-12: revised
- 2026-05-29: received
- See all versions
- Short URL
- https://ia.cr/2026/1094
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2026/1094,
author = {Milan Gonzalez-Thauvin and Keitaro Hashimoto},
title = {Asymmetric Message Franking in the Plain Model: Generic and Efficient Constructions},
howpublished = {Cryptology {ePrint} Archive, Paper 2026/1094},
year = {2026},
doi = {10.1007/978-3-032-35428-0_13},
url = {https://eprint.iacr.org/2026/1094}
}
