Tighter Reduction for Lattice-Based Multisignature
Tighter Reduction for Lattice-Based Multisignature
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DOI:
10.1587/transfun.2020eap1131
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发表时间:
2021
期刊:
影响因子:
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通讯作者:
Masayuki Fukumitsu;Shingo Hasegawa
中科院分区:
文献类型:
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作者:
Masayuki Fukumitsu;Shingo Hasegawa
SUMMARY Multisignaturesenablemultipleuserstosignamessagein-teractively. Many instantiations are proposed for multisignatures, however, most of them are quantum-insecure, because these are based on the integer factoring assumption or the discrete logarithm assumption. Although there existsomeconstructionsbasedonthelatticeproblems,whicharebelievedtobequantum-secure,theirsecurityreductionsareloose.Inthispaper,weaim toimprovethesecurityreductionoflattice-basedmultisignatureschemesconcerningtightness.Ourbasicstrategyiscombiningthemultisignature schemeproposedbyElBansarkhaniandSturmwiththelattice-basedsig-natureschemebyAbdalla,Fouque,Lyubashevsky,andTibouchiwhichhas atightsecurityreductionfromtheRing-LWE(RingLearningwithErrors)assumption.Ourresultshowsthatprooftechniquesforstandardsignature schemescanbeappliedtomultisignatureschemes,thenwecanimprovethepolynomiallossfactorconcerningtheRing-LWEassumption.Oursecond resultistoaddresstheproblemofsecurityproofsofexistinglattice-basedmultisignatureschemespointedoutbyDamgård,Orlandi,Takahashi,and Tibouchi.WeemployanewcryptographicassumptioncalledtheRejected-Ring-LWEassumption,tocompletethesecurityproof.