面向社交网络的隐私保护方案_吕志泉

20148JournalonCommunicationsAugust2014358Vol.35No.8吕志泉1,2，洪澄1，张敏1，冯登国1，陈开渠3(11001902.1000493.518055)TP309A1000-436X(2014)08-0023-10Privacy-perservingschemeforsocialnetworksLVZhi-quan1,2,HONGCheng1,ZHANGMin1,FENGDeng-guo1,CHENKai-qu3(1.TCAInstituteofSoftwareChineseAcademyofSciencesBeijing100190,China;2.UniversityofChineseAcademyofSciences,Beijing100049,China;3.NationalSupercomputingCenterinShenzhen,Shenzhen518055,China)Abstract:ThesecurityandprivacyissuesinSNSwerestudiedandaprivacy-preservingschemePPSNSwasproposed.PPSNSutilizesattribute-basedencryption,allowingtheSNSusertosetupanenforcementoffine-grainedaccesscontroluponthedataheowns,thusthepotentialthreatsfromunauthorizedpartiesoreventheSNSprovideritselfcouldbeavoided.AtokensysteminPPSNSisincludedtoaddressthechallengingissueofefficientattributerevocation.Inaddi-tion,theusersinPPSNSdon’thavetomanageasmuchinformationastheydoinotherencryption-basedsolutions,achievingamuchlowercostintheclientside.AnalysesshowthatPPSNSissecure,andgivesabetterperformanceincomputingandstoragecostscomparedtomostrelatedworks.Keywords:socialnetwork;privacy-preserving;attribute-basedencryption;tokentree;attributerevocation1(SNSsocialnetworkservice)FacebookTwitterSNS[1]()()(DOdataowner)(SNSPSNSprovider)DOSNSP2013-05-062014-03-19(61232005,61100237,91118006)(CXZZ20120831113048965)FoundationItems:TheNationalNaturalScienceFoundationofChina(61232005,61100237,91118006);ShenzhenSpecialFundsforDevelopmentofNewIndustries(CXZZ20120831113048965)doi:10.3969/j.issn.1000-436x.2014.08.0042435[2]FacebookTwitterSNSP[3~9]Flybynight[3]JavaScriptSNSPSNSPNOYB[4]Facecloak[5]SNSPSNSP(CP-ABEciphertext-policyattribute-baseden-cryption)[10][7~9,11~14]CP-ABECP-ABE2DOPersona[7]EASiER[8](AAattributeauthority)Liang[9]DODODODOAADODO231)Persona[7]EASiER[8]DODOLiang[9]DODO2)[7~9][11,15,16][11,15][16]DO3)Persona[7]DOEASiER[8]CP-ABE([12,13,15])PPSNS1)CP-ABEAADO()DODODO2)3)PPSNSSNSP22.11[17]G1G22pe:G1G1G21)u,vG1a,bZpe(ua,vb)=e(u,v)ab2)u,vG1e(u,v)13)u,vG1e(u,v)2.2(CP-ABE)2A={1,2,,k}SASA3ANDORPCP-ABE2825[10][18,19]4[18,19](M,)PMlhi=1,,l,(i)MiSPI={i|(i)S}iMMiM{}ipiIZiiiIM={1,0,,0}SPspZpZh−12v,3v,,hvshv=(s,2v,,hv)i=ivM(i=1,2,,l)S(M,)PiiiI=s33.11PPSNS4AASNSPDO[9,11]AAAASNSPDODODO3.2AA1)SNSPSNSP2)3)SNSP[8]SNSPDO(SSL)4PPSNSPPSNSWT-CP-ABEPPSNS4.15U={u1,,um}A={1,2,,k}G(x)x6xAxTDutG(x)utxxTD4.2WT-CP-ABEWT-CP-ABECP-ABE[19]1)AADODO2)1PPSNS2635WT-CP-ABE51)Setup(1)AA1pgG1eG1G1G2A={1,2,,k}xA(1xk),xxpTDZxxTDxTgZpASK=,{}xxATDAPK=G1,g,g,{}xxAT}xxTDDOZpOSK=gOPK=(,)egg2)KeyGen(ASK,S)ASKStZpD=tgL=tgxS/xxtTDtxxDTgTDKeySKSK=D,L,{}xxSD,TDKeytTDKey3)Encryt(APK,OPK,P,m)APKOPKPm[18]P(M,)Mlhhv=(s,2v,,hv)pZC=m·(,)seggC=sgi{1,2,,l}iMMii=ivM1r,,lrpZiC=()iirigT'iC=irgCTCT=(M,),C,C,{,iC'{1,2,,}}iilC()iT()iTD(iC)()iTD4)KeyUpdate(OSK,SK)OSKSKSKSK=D=tgg,L,{}xxSD,TDKey5)Decrypt(SK,CT)SKCTSKSCT(M,)PI={i|(i)S}W={(i)|(i)S}(i)WTDKey()iTD(4.4)[18]{}iiIiiiI=sA=()'()((,)(,))iiTDiiiiIeCLeCD=()()()()((,)(,))iiiiiiiirTDtTDrtiIegggegg=(,)iiiItegg=(,)tsegg(1)(1)m=C/((,)eCD/A)=C/((,)steggg/(,)tsegg)(2)4.37DD(1~D−1)12DD2D12D2D2H()H()1)njRKj2)njRKinjRKj=H(RKi)3)Flag=1H()ijTK=FlagRKiRKj827ijTK=H(RKi)RKj8(MCKSminimumcoverkeyset)MCKSxMCKS(1xk)xG(x)xxMCKSxx9(KCSkeychainset)KCSiKCS(1im)niKCSini(ni)10(TCStokenchainset)TCSiTCS(1im)niTCSini1nininjRKj=H(RKi)ninjRKj=H(RKi)ijTK=H(RKi)H(RKi)RKjniKCSi2niNSni1NSnjNSncncNSncRKjcjTK=RKjH(RKc)RKj=H(RKc)H()RKcncRKcNS2u6RK6TCS6RK11=H(RK6)611TK=H(RK6)H(RK6)RK11RK14=H(RK11),RK15=H(RK14)1415TK=H(RK14)H(RK14)RK15u623ut(1tm)ntutG(x)(1xk)ntKCSiG(x)MCKSx1)ntKCSiG(x)MCKSxMCKSxKCSiMCKSxntMCKSxntutG(x)MCKSxnt2)ntKCSiG(x)MCKSx12KCSiMCKSxMCKSx2ntMCKSxG(x)4.4AA1Setup(1)ASKAPKDOAAOSKOPKutAAutSKeyGen(ASK,S)SK(SSL)SKutAAu1u2u3{1,2}{1,2,3}{2,3}AAG(1)={u1,u2}G(2)={u1,u2,u3}G(3)={u2,u3}AA(TDMtrapdoormessage)1)4.32835TDKey2)xA(1xk)G(x)MCKSxTDMx={jRKE(xTD)}jxRKMCKSjRKxTDxE24G(4)={u1,u2,u5,u6,u7,u8}MCKS4={RK9,RK14}4TDM4={9RKE(4TD),14RKE(4TD)}3)TDM={}xxATDMTCS={1,2,,}{}iimTCSDOOSKDO1)DEKfDEKEnc(f)(Enc)2)PEncryt(APK,OPK,P,m)DEKCTf3)V={(i)|1il}xVTDMxTDMf={}xxVTDMIDf||TDMf||CTf||DEKEnc(f)(IDf)utIDfSNSPTDMf||CTf||DEKEnc(f)TCStutTDMfSKCTfDEKDEKTDMf1utSKTDKeyTCStKCStutCTfSKS(M)W={(i)|1il(i)S}xWG(x)utG(x)MCKSxG(x)3RKyKCStRKyMCKSxutRKyTDMxxTDutTDMfCTf2u2TCS2=29TK||Flag||FlagRK9RK13RK15RK94TDM44TDCTfutKeyUpdate(OSK,SK)SKDecrypt(SK,CT)CTfDEKAARut1)AAxR'xTDG(x)xutG(x)MCKSx’TDMx’={jRKE('xTD)'}jxRKMCKSTDMx’TDMx2AAu24G(4)={u1,u5,u6,u7,u8}MCKS4’={RK1,RK14},TDM4’={1RKE('4TD),14RKE('4TD)}2u2RK9RK13RK154'4TD2)AAAPKASKxRAPK'xT='/xxTDTDxT='xTDihASKxTD'xTD3)DODEK’'DEKE(f)Encryt(APK,OPK,P,m)DEK’'fCTV={(i)|1il}VR=VR(R)VR=xVRTDMxTDMx’[20,21]8292AADO()55.1[11,15]PPSNSAAAA5.2PPSNSWT-CP-ABEWT-CP-ABECP-ABE[19]PBDHEWT-CP-ABECP-ABE[19]1)DOOSKOSK2)xTDxTDxTDx12WT-CP-ABEAA5.3SNSP[8,11~13,15]PPSNSDOSNSP2[10,19]PPSNSDEK(,)seggDEK(,)segg4.2(,)eCD/(,)tsegg(,)tsegg()i(iI)'(