Faulty instantiations of threshold ring signature from threshold proof-of-knowledge protocol

Authors

Joseph K. Liu, Monash UniversityFollow
Sze Ling Yeo, Institute for Infocomm Research Singapore
Wun-She Yap, Universiti Tunku Abdul Rahman
Sherman S. M. Chow, Chinese University of Hong KongFollow
Duncan S. Wong, City University of Hong KongFollow
Willy Susilo, University of WollongongFollow

RIS ID

109202

Publication Details

Liu, J. K., Yeo, S., Yap, W., Chow, S. S M., Wong, D. S. & Susilo, W. (2016). Faulty instantiations of threshold ring signature from threshold proof-of-knowledge protocol. The Computer Journal, 59 (7), 945-954.

Abstract

In this paper, we point out some faulty instantiations of threshold ring signatures (TRS) based on the threshold proof-of-knowledge (TPoK) protocol. Although a TRS can be regarded as the non-interactive version of the TPoK, the computational domains of the variables should be carefully chosen. We show that by choosing some inappropriate domains, two such instantiations suffer from forgery and anonymity attacks. Our attacks rely on algebraic techniques which involve solving some particular instances of the well-known subset sum problem. While we focus our attacks on two particular instantiations of the TRS, they are generic and are applicable to other schemes with the same choice of domains or a similar structure. We believe this paper can act as an important security remark on the design of future TRS schemes.