A trustless GQ multi-signature scheme with identifiable abort

Handong Cui, Tsz Hon Yuen

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

2 Citations (Scopus)


Guillou-Quisquater (GQ) signature is an efficient RSA-based digital signature scheme amongst the most famous Fiat-Shamir follow-ons owing to its good simplicity. However, there exist two bottlenecks for GQ hindering its application in industry or academia: the RSA trapdoor n= pq in the key generation phase and its high bandwidth caused by the storage-consuming representation of RSA group elements (3072 bits per one element in 128-bit security). In this paper, we first formalize the definition and security proof of class group based GQ signature (CL-GQ), which eliminates the trapdoor in key generation phase and improves the bandwidth efficiency from the RSA-based GQ signature. Then, we construct a trustless GQ multi-signature scheme by applying non-malleable equivocable commitments and our well-designed compact non-interactive zero-knowledge proofs (NIZK). Our scheme has a well-rounded performance compared to existing multiparty GQ, Schnorr and ECDSA schemes, in the aspects of bandwidth (no range proof or multiplication-to-addition protocol required), rather few interactions (only 4 rounds in signing), provable security in dishonest majority model and identifiable abort property. Another interesting finding is that, our NIZK is highly efficient (only one round required) by using the Bezout formula, and this trick can also optimize the ZK proof of Paillier ciphertext which greatly improves the speed of Yi’s Blind ECDSA (AsiaCCS 2019).

Original languageEnglish
Title of host publicationInformation Security and Privacy - 26th Australasian Conference, ACISP 2021 Virtual Event, December 1–3, 2021 Proceedings
EditorsJoonsang Baek, Sushmita Ruj
Place of PublicationCham Switzerland
Number of pages21
ISBN (Electronic)9783030905675
ISBN (Print)9783030905668
Publication statusPublished - 2021
Externally publishedYes
EventAustralasian Conference on Information Security and Privacy 2021 - Online, Australia
Duration: 1 Dec 20213 Dec 2021
Conference number: 26th
https://link.springer.com/book/10.1007/978-3-030-90567-5 (Proceedings)

Publication series

NameLecture Notes in Computer Science
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349


ConferenceAustralasian Conference on Information Security and Privacy 2021
Abbreviated titleACISP 2021
Internet address


  • Guillou-Quisquater signature
  • Multi-signature
  • Remove trusted setup
  • Zero-knowledge proof

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