多媒體快速加密算法研究.pdf

1、南京理工大學博士學位論文多媒體快速加密算法研究姓名：廉士國申請學位級別：博士專業(yè)：控制科學與工程指導教師：王執(zhí)銓20050501博士學位論文多媒體快速加密算法研究AbstractWlththedevelopmentofmultimediatechnologyandnetworktechnologymultimediadataaleusedmoreandmorewidelyInordertopmtectmultimediadata，som

2、e電ncryptionalgorithmshavebeenstudiedInthispaperthefastmultimediaencryptionalgorithmsarestudied，andtheirperformancesareanalyzedandtestedSomeoftheconclusionsarelistedasf0NowsFirst，thesecurityofFridrich’Schaoticcipherisanal

3、yzedthoroughlyaccordingtobrutvforcespaceparametersensitivityknownplaintextattackandselectplaintextattack，Additionallytherelationshipbetweenthesecurityandcomputingcomplexityisstudied，andsomemeansalepresentedtostrengthenth

4、ecrypmsyStemBasedontheaboveanalysis，ablockcipherbasedonStandardmapispresented，whichsupportsplaintextswithvariouslengths，haslowcosLandisthussuitableformultimediaencryptionSecondlyaselectiveencryptionmodelisproposed，togeth

5、erwithsomeenctyptionprinciplesandtleirverificationAsexamplestheselectivee!acryptionalgorithmscombinedwithfractalimagecoding皿l蛤2000andMPEG2arepresentedSomepropertiesaleobtained，suchaslowCOSt，highsecuritykeepingfileformatu

6、nchangedandsupportingdirectoperations(browsing，Cutting，etc)Thirdlyaneneryptionmodelcombin酣withcompressionprocessisproposed，whoseperformancesareanalyzedAsexamplestheenctyptionalgorithmsarepresentedwhichcombinewithJPEGIMPE

7、G2andJPEG2000111eyoftenrealizecompressionandencryptionatthesametime，keeplowcost，andsupportsuchdirectoperationsasbrowsing，cutting，bitratecontrolorrecompressionThesepropertiesmakethemsuitableforsomeapplicationswithlowsecur

8、ityreal—timeoperationanddkectoperationrequirementsFourthlyanimprovedperceptualcryptographyispresented，whichsupportsdirectbitratecontr01Duringcompressionprocess，theciphertext’8qualityiscontrolledbytheencryptionqualityfact

9、orCombinedwithJPEGMPEG2andJPEG2000，severalperceptualencryptionalgorithmsaleconstructedandanalyzedThesealgorithmsaresuitableforsuchapplications鶘videoondemandaudio0n—demandandSOonFifthlyaSecUmmultimediatransmissionschemeis