Efficient escrow-free identity-based signature

Yunmei Zhang, Joseph K Liu, Xinyi Huang, Man Ho Allen Au, Willy Susilo

Research output: Chapter in Book/Report/Conference proceedingConference PaperResearchpeer-review

7 Citations (Scopus)


The notion of identity-based signature scheme (IBS) has been proven useful in some scenarios where relying on the validity of the certificates is impractical. Nevertheless, one remaining inherent problem that hinders the adoption of this cryptographic primitive in practice is due to the key escrow problem, where the private key generator (PKG) can always impersonate the user in the system. In 2010, Yuen et al. proposed the notion of IBS that does not suffer from the key escrow problem. Nevertheless, their approach relies on the judge who will later blame the malicious PKG when such a dispute occurs, assuming that the PKG is willing to collaborate. Although the approach is attractive, but unfortunately it is impractical since the malicious PKG may just refuse to collaborate when such an incident happens. In this paper, we propose a new escrow-free IBS, which enjoys three main advantages, namely key escrow free, practical and very efficient. We present a generic intuition as well as an efficient instantiation. In our approach, there is no judge involvement required, as the public can determine the malicious behaviour of PKG when such an incident happens. Further, the signature size of our instantiation is only two group elements, which outperforms the existing constructions in the literature.
Original languageEnglish
Title of host publication6th International Conference on Provable Security (ProvSec 2012)
EditorsTsuyoshi Takagi, Zhiguang Qin, Yong Yu
Place of PublicationHeidelberg Germany
Pages161 - 174
Number of pages14
ISBN (Print)9783642332715
Publication statusPublished - 2012
Externally publishedYes
EventInternational Conference on Provable Security 2012 - Chengdu, China
Duration: 26 Sept 201228 Sept 2012
Conference number: 6th
https://link.springer.com/book/10.1007/978-3-642-33272-2 (Proceedings)


ConferenceInternational Conference on Provable Security 2012
Abbreviated titleProvSec 2012
Internet address

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