HDCP-Presentation

IntroduceHDCPHigh-bandwidthDigitalContentProtectionSystemWhatisHDCPHDCP1.1isdesignedforprotectingAudiovisualcontentovercertainhigh-bandwidthinterfacesfrombeingcopied.HDCP1.0→DVIHDCP1.1→DVIandHDMIRequirealicensefromtheDigitalContentProtectionLLC.()HDCPDefinitionsDeviceKeySetKeySelectionVector+DevicePrivateKeysKeySelectionVector(KSV)ItisUniqueforeachHDCPDevice.KSVisa40-bitbinaryvalue.KSVcontains20onesand20zeros.(40!/(20!*20!)=137,846,528,820)DevicePrivateKeys.Itconsistsof40different56-bitvalues.每一個DHCPDevice都必須有一組唯一的DeviceKeySet(40/8+56/8*40=285bytes)HDCPSystemHDCPTransmitterHDCPRepeaterHDCPReceiverHDCP-protectedInterfaceDVIHDMI(HighDefinitionMultimediaInterface)I2CBus(DDC)ForHDCPAuthenticationprotocolHDCPSystemAllowsupto7levelsofHDCPrepeaters.128totalHDCPdevices,includingHDCPrepeaters.HDCPSystemContent傳送流程1.建立HDCPAuthenticationprotocol2.經DVI或HDMI傳送加密的Content.HDCPAuthenticationprotocolHDCP認證協定包含3部分認證機制(協定)的初始化和建立Repeater回報所連接的Receiver的KSV.內容開始傳輸後，在VerticalBlanking持續做認證檢查。HDCPAuthenticationprotocol第一部份:認證機制的初始化和建立HDCP認證協定的初始化和建立相關名詞說明–I:DeviceA:Transmitter,DeviceB:Receiver.Aksv:Transmitter’sKSV.KSVcontains20onesand20zeros.Bksv:Receiver’sKSV.An:a64-bitpseudo-randomvaluegeneratedbyTransmitter.REPEATER:abitwhichindicatesthatDeviceBisaRepeater.HDCP認證協定的初始化和建立相關名詞說明–II:Km:利用Bksv中為1的bit當索引從40組Keyset中找出20組key,再將這20組Key加總的結果即為所得.Ks:56-bitvalue,供HDCP內容編碼用.M0:64-bit供HDCP認證協定的第二部分用.R0:16-bitvalue,與Receiver回傳的R0’相同,認證才會通過.Km’,Ks’,M0’,R0’:為Receiver產生的,意義與上述的內容相同HDCP認證協定的初始化和建立HDCP認證協定的初始化–PartI由Transmitter端發起,可以在任何時候開始(主控權在Transmitter端,想做就做)1.由Transmitter送出An,Aksv.2.Receiver回傳Bksv,REPEATERbit.3.Transmitter檢查BKSV.(20個1,20個0;Revoked)4.Transmitter和Receiver各自利用所得的ksv做運算,算出Km,Ks,M0,R0.(Receiver端為Km’,Ks’,M0’,R0’).HDCP認證協定的初始化和建立HDCP認證協定的初始化–PartII5.Transmitter讀取Receiver運算出的R0’.6.Transmitter比較R0是否等於R0’,若相等,則通過HDCP認證,否則HDCP認證協定失敗.7.Receiver必須在收到(An,Aksv)後在100ms內將R0’準備好。8.Transmitter送出(An,Aksv)後至少等100ms後再檢查R0’9.認證成功後,Transmitter將開始加密傳送內容.HDCPAuthenticationprotocol第二部分:TheHDCPReceiverisanHDCPRepeaterHDCP認證協定-Repeater認證設5秒TimerTransmitter等待Repeater蒐集所有連接的Receiver和Repeater的ksv,然後將此資料上傳至Transmitter.Transmitter檢查收到的資料是否正確(V==V’)。HDCP認證協定-Repeater認證Repeater認證失敗的因素V≠V’若Transmitter收到的KSVList超過其容量,則認證將失敗。DEVICE_COUNT127,DEVICE_DEPTH7KSVList中有KSV在RevocationList裡。HDCPAuthenticationprotocol第三部份:內容傳輸進行時的認證HDCP認證協定–內容傳輸的認證第三部份:內容傳輸進行時的認證1.在VBlanking運作.2.Transmitter和Receiver各自運算出(Ki,Mi,Ri).3.Theindexi,istheframenumber,startingwiththevalueofoneforthefirstframe.4.每128個Frame更新一次Ri。5.Transmitter至少2秒檢查一次。6.讀取Ri的動作必須在1millisecond完成.HDCP認證協定–內容傳輸的認證第三部份:內容傳輸進行時的認證6.EnhanceLinkVerificationBcapsbit1.1_FEATURESissetOptionforDVI,但是在HDMI上是必備的。每16個Frame更新Rj’和Pj’,連續3次錯誤才算失敗。7.在HDMI上有增加一些規定,用來處理傳輸時同步的問題,如ADVANCE_CIPHERmode,在HDMImodeAV_MUTE相關的動作.HDCPTransmitterStateDiagramHDCPTransmitterLinkStateDiagramHDCPTransmitterStateDiagramHDCPTransmitterLinkStateDiagram(I)StateH0:ResetTransitionH0-H1:有HPD或偵測到有Receiver存在.StateH1:讀取EDID,決定傳輸方式.(OutputTiming,Signalformat,Audioornoaudio,……)TransitionH1-H2/H3:Transmitter送出未加密的Video信號通知Receiver.(Tx存在)HDCPTransmitterStateDiagramHDCPTransmitterLinkStateDiagram(II)StateH2/H3:none.TransitionH2/H3-A0:若Transmitter要用HDCP方式傳送,則進入A0.(ItisdesiredbyUpstreamContentControlFunction.)StateA0:WaitforActiveReceiver.HDCPTransmitterStateDiagramHDCPTransmitterStateDiagramHDCPTransmitterAuthenticationProtocolStateDiagram(I)A0:WaitforActiveReceiver.Transmitter應送出一適當的Video信號(如藍畫面,信息提示畫面),以避免在HDCPAuthentication未完成前,使用者因未看到畫面而切換到其他VideoSource.每2秒PollingReceiver,讀取Bksv,直到Receiver回覆Bksv為止.HDCPTransmitterStateDiagramHDCPTransmitterAuthenticationProtocolStateDiagram(II)TransitionA0-A1:Transmitter收到有效的Bksv後,將展開HDCP認證的程序.StateA1:ExchangeKSVs.1.GenerateAnandwriteittoRx.2.讀取BcapsRegister,決定採用DVIorHDMI.3.若要用AdvanceCipheroption,設定Ainfo.4.WriteAksv.5.ReadBksvandREPEATERbit.HDCPTransmitterStateDiagramHDCPTransmitterAuthenticationProtocolStateDiagram(III)TransitionA1-A0:FailuretoreadBksv.TransitionA1-A2:An,Aksv已寫入,Bksv,REPEATERbit已收到,且Bksv格式正確.StateA2:Computations.計算Km,Ks,M0,R0.TransitionA2-A3:StateA2計算完成後進入A3.HDCPTransmitterStateDiagramHDCPTransmitterAuthenticationProtocolStateDiagram(IV)StateA3:ValidateReceiver.1.若R0=R0’,開始啟動HDCP加密機制.2.要保留100ms以上的時間,讓Receiver計算R0’.3.若Bksv在revocationlist中,則判定HDCP認證失敗.TransitionA3-A0:認證失敗.TransitionA3-A6:認證成功.StateA4:認證完成HDCPTransmitterStateDiagramHDCPTransmitterAuthenticationProtocolStateDiagram(V)TransitionA4-A5:VerificationTimerEvent(every128frames).StateA5:LinkIntegrityCheck.在連結期間持續檢查Ri.TransitionA5-A4:Ri=Ri’.TransitionA5-A0:LinkIntegrityCheck失敗.(1)Ri≠Ri’,(2)R0’沒在1ms內回覆.HDCPTransmitterStateDiagramHDCPTransmitterAuthenticationProtocolStateDiagram(VI)StateA6:TestforRepeater.REPEATERbit?TransitionA6-A4:REPEATERbit=0.TransitionA6-A8:REPEATERbit=1.StateA8:WaitforReady.設5秒timer,等Repeater’sREADYbit設定.TransitionA8-A0:超過5秒,READYbit沒被設定.HDCPTransmitterStateDiagramHDCPTransmitterAuthenticationProtocolStateDiagram(VII)TransitionA8-A9:READYbit被設定.S