Paper 2008/537
A Secure Threshold Anonymous Password-Authenticated Key Exchange Protocol
SeongHan Shin, Kazukuni Kobara, and Hideki Imai
Abstract
At Indocrypt 2005, Viet et al., [22] have proposed an anonymous password-authenticated key exchange (PAKE) protocol and its threshold construction both of which are designed for client's password-based authentication and anonymity against a passive server, who does not deviate the protocol. In this paper, we first point out that their threshold construction is completely insecure against off-line dictionary attacks. For the threshold t > 1, we propose a secure threshold anonymous PAKE (for short, TAP) protocol with the number of clients n upper-bounded, such that n \leq 2 \sqrt{N-1} -1, where N is a dictionary size of passwords. We rigorously prove that the TAP protocol has semantic security of session keys in the random oracle model by showing the reduction to the computational Diffie-Hellman problem. In addition, the TAP protocol provides unconditional anonymity against a passive server. For the threshold t=1, we propose an efficient anonymous PAKE protocol that significantly improves efficiency in terms of computation costs and communication bandwidth compared to the original (not threshold) anonymous PAKE protocol [22].
Note: In this paper, we added some comments (including an attack) on Yang and Zhang's Indocrypt2008 paper.
Metadata
- Available format(s)
-
PDF
- Category
- Cryptographic protocols
- Publication info
- Published elsewhere. This is the full version of IWSEC2007 paper.
- Keywords
- password authenticationkey exchangePAKEanonymityprovable security
- Contact author(s)
- seonghan shin @ aist go jp
- History
- 2008-12-28: received
- Short URL
- https://ia.cr/2008/537
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2008/537,
author = {SeongHan Shin and Kazukuni Kobara and Hideki Imai},
title = {A Secure Threshold Anonymous Password-Authenticated Key Exchange Protocol},
howpublished = {Cryptology {ePrint} Archive, Paper 2008/537},
year = {2008},
url = {https://eprint.iacr.org/2008/537}
}
