Paper 2020/848
On Composability of Game-based Password Authenticated Key Exchange
Marjan Škrobot and Jean Lancrenon
Abstract
It is standard practice that the secret key derived from an execution of a Password Authenticated Key Exchange (PAKE) protocol is used to authenticate and encrypt some data payload using a Symmetric Key Protocol (SKP). Unfortunately, most PAKEs of practical interest are studied using so-called game-based models, which – unlike simulation models – do not guarantee secure composition per se. However, Brzuska et al. (CCS 2011) have shown that middle ground is possible in the case of authenticated key exchange that relies on Public- Key Infrastructure (PKI): the game-based models do provide secure composition guarantees when the class of higher-level applications is restricted to SKPs. The question that we pose in this paper is whether or not a similar result can be exhibited for PAKE. Our work answers this question positively. More specifically, we show that PAKE protocols secure according to the game-based Real-or-Random (RoR) definition with the weak forward secrecy of Abdalla et al. (S&P 2015) allow for safe composition with arbitrary, higher-level SKPs. Since there is evidence that most PAKEs secure in the Find-then-Guess (FtG) model are in fact secure according to RoR definition, we can conclude that nearly all provably secure PAKEs enjoy a certain degree of composition, one that at least covers the case of implementing secure channels
Metadata
- Available format(s)
-
PDF
- Category
- Cryptographic protocols
- Publication info
- Published elsewhere. Minor revision. 2018 IEEE European Symposium on Security and Privacy (EuroS&P)
- DOI
- 10.1109/EuroSP.2018.00038
- Keywords
- Password Authenticated Key ExchangeComposabilityComposition Theorem.
- Contact author(s)
- marjan skrobot @ gmail com
- History
- 2020-07-12: received
- Short URL
- https://ia.cr/2020/848
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2020/848,
author = {Marjan Škrobot and Jean Lancrenon},
title = {On Composability of Game-based Password Authenticated Key Exchange},
howpublished = {Cryptology {ePrint} Archive, Paper 2020/848},
year = {2020},
doi = {10.1109/EuroSP.2018.00038},
url = {https://eprint.iacr.org/2020/848}
}
