International Association for Cryptologic Research

International Association
for Cryptologic Research

CryptoDB

Swee-Huay Heng

Publications

Year
Venue
Title
2006
PKC
2005
EUROCRYPT
2005
PKC
2004
PKC
2004
EPRINT
The Security of the FDH Variant of Chaum's Undeniable Signature Scheme
Wakaha Ogata Kaoru Kurosawa Swee-Huay Heng
In this paper, we first introduce a new kind of adversarial goal called {\em forge-and-impersonate} in undeniable signature schemes. Note that forgeability does not necessarily imply impersonation ability. We then classify the security of the FDH variant of Chaum's undeniable signature scheme according to three dimensions, the goal of adversaries, the attacks and the ZK level of confirmation and disavowal protocols. We finally relate each security to some well-known computational problem. In particular, we prove that the security of the FDH variant of Chaum's scheme with NIZK confirmation and disavowal protocols is equivalent to the CDH problem, as opposed to the GDH problem as claimed by Okamoto and Pointcheval.

Program Committees

Asiacrypt 2020

Coauthors

Kaoru Kurosawa (5)
Wakaha Ogata (2)