简介:Inthispaper,weputforwardaweakblindquantumsignatureschemebasedonquantumentanglementswappingofBellstates.Differentfromtheexistingquantumsignatureschemes,ourschemecanoffertwo-stepverificationsecurityservicestoensurethevalidityoftheverification.Inordertoguaranteetheunconditionalsecurityofthescheme,thequantumkeydistributionprotocolandone-timepadencryptionalgorithmareemployedinourscheme.Besides,theentanglementswappingofBellstatesmechanismenhancesthesecurityofverificationcriteria.Theproposedschemehasthepropertiesofnonforgeability,nonrepudiation,lindness,andtraceability.
简介:Recently,Liuetal.[Commun.Theor.Phys.57(2012)583]proposedaquantumprivatecomparisonprotocolbasedonentanglementswappingofBellstates,whichaimstosecurelycomparetheequalityoftwoparticipants’informationwiththehelpofasemi-honestthirdparty(TP).However,thepresentstudypointsoutthereisafatalloopholeinLiuetal.’sprotocol,andTPcanmakeBell-basismeasurementtoknowalltheparticipants’secretinputswithoutbeingdetected.Tofixtheproblem,asimplesolution,whichusesone-timeeavesdroppercheckingwithdecoyphotonsinsteadoftwiceeavesdroppercheckingwithBellstates,isdemonstrated.Comparedwiththeoriginalprotocol,itnotonlyreducestheBellstatesconsumptionbutalsosimplifiestheprotocolsteps.
简介:TheInternetevolvestoincorporatevery-high-bandwidthopticallinksandmorelarge-delaysatellitelinks.TCPfacesnewchallengesinthisuniqueenvironment.TheoryandexperimentsshowedthatTCPbecomesinefficientandispronetobeunstableastheper-flowproductofbandwidthandlatencyincreases,regardlessofthequeuingscheme.Variable-structurecongestionControlProtocol(VCP)isproposedtoaddresstheseproblems.However,VCPhasproblemintermsofconvergencetime,i.e.,ittakesalongtimeforanewVCPflowtoachievefairbandwidthallocationiftheexistingVCPflowshavelargecon-gestionwindows.ThispaperproposedanExtendedVariable-structurecongestionControlProtocol(EVCP),whichadoptedaconvergencecontroller.Thebasicideaofconvergencecontrolleristhatifaflowhaslargerwindowthanitsfairwindow,itscongestionwindowshouldbedecreasedmoreaggressivelythanusualinMultiplicativeDecrease(MD)phase.SimulationsshowedthatEVCPhasbetterperformanceintermsofconvergencetimewhilekeepingtheadvantagesofVCP.