数字语音和高保真音频信号中的安全密写

《数字语音和高保真音频信号中的安全密写》由会员上传分享，免费在线阅读，更多相关内容在行业资料-天天文库。

1、上海大学博士学位论文数字语音和高保真音频信号中的安全密写姓名：胡礼才申请学位级别：博士专业：通信与信息系统指导教师：王朔中20070201上海大学博士学位论文作为音频密写研究的一项基础性工作，本文还分析研究了多种用于音频信号质量评估的主、客观测试方法。在本论文的实验研究中，分别选择PESQ和PEAQ算法软件，用于窄带语音和宽带音频密写信号质量的客观评估。这些客观评估方法，用于音频密写和编码研究，可在很大程度上替代耗资费时的主观评估。关键词：信息隐藏、密写、动态有效位、语音压缩、主观评估、客观评估上海大

2、学博士学位论文ABSTRACTWithrapiddevelopmentoftheinformationtechnologyandcomputerscience，informationsecurityhasbecomeacrucialissuethatiscloselyrelatedtosocialstabilityandnationalsecurity．Asagrowingareaofinformationsecurityresearch,informationhiding，includingdigi

3、talwatermarkingandsteganography,hasreceivedenornlousattentionfromtheacademia，theindustry,andvariousorganizations．Watermarkingaimstoprotectintellectualpropertyfightsofmultimediacontents，whilesteganographyistosendsecretmessageunderthecoverofcarriersignals

4、．Byinsertingsecretdataintodigitalmediasuchasimage，audioandvideo，onecansendasecretmessageimperceptiblythroughpublicchannels，especiallytheInternet．Asanimportantcomponentofthedigitalmedia，digitalspeechandhighfidelitydigitalaudioCanbeusedascoversforsuchhidd

5、encommunications．Thisdissertationstudiessteganographictechniquesthatusedifferentformsofdigitalaudiosignalsascovers，includinglinearPCMspeech，compressedspeechandcompressedaudiocodedbitstreams，andproposesthreenewerneddingschemes．Theresearchfindingsreported

6、inthisdissertationaresummarizedasfollows．1．Anovelsteganographicmethodisproposedbasedonadynamicsignificantbit(DSB)modificationscheme．WithDSB，theembeddeddataarerobustagainstAlawandplawcompressioncoding，andCanresistconversionbetweenthesetwolawsSOthattheste

7、go·speechCansurvivetransmissionthroughtheInternetandPSTN．Experimentalresultsshowthat，whentheembeddingcapacityisbelow20％，differencebetweenthestego-speechandthecarrierisimperceptibleundersubjectivetesting，histogramcomparison，andspectrogramobservation．2．An

8、embeddingtechniqueisdevelopedtohidesecretdatainGSMfullratetranscodingbit—streams．Inthismethod，the$econdbitsofRegularPulseExcitation(RPE)samplesarereplacedwiththesecretbitsandthethirdbitsofRPEarejointlyalteredsometimesinordertored