A Lattice-Based Provably Secure Multisignature Scheme in Quantum Random Oracle Model

Masayuki Fukumitsu, Shingo Hasegawa

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

The multisignature schemes are attracted to utilize in some cryptographic applications such as the blockchain. Though the lattice-based constructions of multisignature schemes exist as quantum-secure multisignature, a multisignature scheme whose security is proven in the quantum random oracle model (QROM), rather than the classical random oracle model (CROM), is not known. In this paper, we propose a first lattice-based multisignature scheme whose security is proven in QROM. The difficultly of proving the security in QROM than CROM is how to program the random oracle in the security proof. Although our proposed scheme is based on the Dilithium-QROM signature whose security is proven in QROM, their proof technique cannot be directly applied to the multisignature setting. To solve the problems in the security proof, we develop several proof techniques in QROM. First, we employ the searching query technique by Targi and Unruh to convert the Dilithium-QROM into the multisignature setting. For the second, we develop a new programming technique in QROM, since the conventional programming techniques seem not to work in the multisignature setting of QROM. We combine the programming technique by Unruh with the one by Liu and Zhandry. The new technique enables us to program the random oracle in QROM and to construct the signing oracle in the security proof.

Original languageEnglish
Title of host publicationProvable and Practical Security - 14th International Conference, ProvSec 2020, Proceedings
EditorsKhoa Nguyen, Wenling Wu, Kwok Yan Lam, Huaxiong Wang
PublisherSpringer Science and Business Media Deutschland GmbH
Pages45-64
Number of pages20
ISBN (Print)9783030625757
DOIs
Publication statusPublished - 2020
Event14th International Conference on Provable Security, ProvSec 2020 - Singapore, Singapore
Duration: 2020 Nov 292020 Dec 1

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Volume12505 LNCS
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349

Conference

Conference14th International Conference on Provable Security, ProvSec 2020
CountrySingapore
CitySingapore
Period20/11/2920/12/1

Keywords

  • CRYSTALS-Dilithium
  • Lattice cryptography
  • Multisigature
  • Quantum random oracle model

ASJC Scopus subject areas

  • Theoretical Computer Science
  • Computer Science(all)

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