Paper 2025/571
Universally Composable Relaxed Asymmetric Password-Authenticated Key Exchange
, Institute of Science Tokyo, Institute of Science Tokyo, Institute of Science Tokyo, Institute of Science TokyoAbstract
Password-Authenticated Key Exchange (PAKE) establishes a secure channel between two parties who share a password. Asymmetric PAKE is a variant of PAKE, where one party stores a hash of the password to preserve security under the situation that the party is compromised. The security of PAKE and asymmetric PAKE is often analyzed in the framework of universal composability (UC). Abdalla et al. (CRYPTO '20) relaxed the UC security of PAKE and showed that the relaxed security still guarantees reasonable properties. This relaxation makes it possible to prove the security in the UC framework for several PAKE protocols. In this paper, we propose a relaxed functionality of asymmetric PAKE by following the approach of Abdalla et al. We prove that the SPAKE2+ protocol UC-realizes this functionality. We also define a more relaxed functionality and prove that a variant of the AuCPace protocol UC-realizes it.
Metadata
- Available format(s)
-
PDF
- Category
- Cryptographic protocols
- Publication info
- Published elsewhere. Major revision. SCN2024
- DOI
- 10.1007/978-3-031-71073-5_13
- Keywords
- aPAKEUniversal Composability
- Contact author(s)
-
hanai s ac @ m titech ac jp
keisuke @ is titech ac jp
tezuka m ac @ m titech ac jp
yoshida yusuke @ c titech ac jp - History
- 2025-04-01: approved
- 2025-03-29: received
- See all versions
- Short URL
- https://ia.cr/2025/571
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2025/571,
author = {Shuya Hanai and Keisuke Tanaka and Masayuki Tezuka and Yusuke Yoshida},
title = {Universally Composable Relaxed Asymmetric Password-Authenticated Key Exchange},
howpublished = {Cryptology {ePrint} Archive, Paper 2025/571},
year = {2025},
doi = {10.1007/978-3-031-71073-5_13},
url = {https://eprint.iacr.org/2025/571}
}
