直接匿名證言方案的改進與實現.pdf

1、河南大學碩士學位論文直接匿名證言方案的改進與實現姓名：劉明理申請學位級別：碩士專業(yè)：計算機應用技術指導教師：劉景森20080501第1I頁河南大學研究生碩士學位論文AbstractT11lstedComputingGroupbelieVesthatpriVacyprotectionisoneofnecessa拶eIementsoft11】stedcomputingsystems，andusersmusthavetheri西tstocho

2、oseandconnoltheirprivateinfbmationIn2003，toensuretheanonym時inauthenticationandresolVetheproblemsofPriVacyCAscheme，TmstedComputingGroupissuedDAAschemeHoweVer，theDAAschemeisnotVe哆satisfacto叫inrealsystemsforitsspendingtoomu

3、chtimeInthispaper，somespecialschemeswhichcallbeachieveda110n1忡i戧suchassi印a吡reproxysi印amreschemes，blindsi印amreschemesandgroupsi朗amreschemes，arestudiedThenthebackground，thestageofdeVelopmentandtheachievingmechanismsofDAAsc

4、hemearealsostudiedInthe行ameworkofDAAanonvmousmechanism，themainmethodofreducingtimeexpenSeistoshortenthelengthofparametersButonlytoshortenthepar鋤eterslen酉h，willthesecuritybedecreasedtooToshortent量1elengtllofpar鋤eterSandgu

5、aranteethesecurityandanonym岫ofnewscheme，wemaychangethediscretelogarithmproblemintoellipticcurvesc拶ptosystemHoweVer，DAAschemeistheschemewhichisinte黟atedbyfactoringintegerSanddiscretelogarit王1IIlproblem，justchangingthedisc

6、retelogarithmproblemintoe11ipticcurvesc聊tosystems，willmaketheschemeunsafeForthesereasons，anewschemehasbeenofferedInthenewscheme，factoringintegersanddiscretelogarithmproblemarediscarded，andanewmethodwasjoined，sotherequire

7、mentsoftheoriginalschemewouldbeachievedbyellipticcurvesc眄ptosystemFinally，wecomparesthenewschemewiththeoriginalscheme0nthesecurity，theaJlonymit)，鋤dthee筒ciencyInordertocanyoutthee筒ciencyanalysis，thenewschemeaIldtheori百nal

8、schemearesimulated111theimplementation，theoperationofcommunicationisomittedandastandaloneversioniscarriedout111thesimulationprogr鋤s，theclassofsetupforproducingapublickey，theclassofHashforconstmctinghashmnction，theclassof

9、TPMforimplementingthemnctionsofTPM，theclassofhost，theclassofissuer，meclassofvenfication，theclassofdaaandtheclassofeccareallcons仃uctedComparingwiththeoriginalscheme，thenewschemedoesnotdecreasethesafetyandanonymi夠Atthesame