资源描述：
《电子与通信技术专业英语 第3版 2 作者 刘小芹 刘骋 Unit Five》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。
1、UnitFiveTextATextB能力分析训练TextA1.Digitized“E-cash”SystemsAnumberofcompaniesaredevelopingpaymentsystemspermittingdirectpaymentstobemadeanonymously.Paymenttakestheformofencodedmessages,whichrepresentstheencryptedequivalentofdigitizedmoney.Theaimistobeabletoeffec
2、tpaymentdirectlywithoutrequiringtheuseofintermediaries.Oneoftheleadingfirms,whicharedevelopingane-cashsystem,isDigiCash,whichhaspreviouslybeeninvolvedindevelopingsmartcardtechnologies.DigiCashisaDutchcompanybasedinAmsterdam.IthasbeenrunningtrialssinceNovembe
3、r,1994,involvingthetransmissionofwhatiseffectivelyelectronicmoneyusingmorethanthirtysellerslinkedtotheInternet.Paymentsconsistofuniquelycodeddigitaltokensestablishedinsuchawayastopreventduplicationorfraud.ThekeytotheDigiCashsystemisanonymity.Apersonwhospends
4、oneofitselectronictokensdoesnotneedtorevealhisorheridentitytothebuyernortoanythirdpartyexceptwhenthereisanattemptatfraud,i.e.,whenthesamepieceofdigitalmoneyispresentedtwiceforpayment.Anumberofcompaniesareattemptingtoovercomethesecurityissuesinvolvedinhandlin
5、gpaymentsontheInternetbyestablishingelectronicclearingsystems.Essentiallytheserviceonofferinvolvesasystemofsecuremessageswhichpermitbuyerandsellertocommunicatewitheachother,whilealsopermittinginstructionstomakepaymenttobesentviathemessage/paymentclearer,freq
6、uentlyusingexistingproprietarynetworks.2.PaymentClearingSystemsOneexampleisFirstVirtualHoldingswhichisastart-upcompanybasedinCheyenne,Wyoming.FirstVirtualhasdevelopedasystemforlinkingcreditcard,banksandprocessingagentswiththeInternet.Ithasdevelopedaclosedloo
7、ppaymentsystemwhichinvolvestheoneofFirstVirtual,whichprovidesamailboxfromwhichinstructionstomakethepayment.TheFirstVirtualsystemhasbeeninoperationsinceOctober,1994,andisseentohavetheadvantagethatitdoesnotrequireencryptedmessagesasdoothercreditcard-basedsyste
8、ms.FirstVirtualcheckswiththebuyerthataparticulartransactionistogoaheadbeforearrangingtheappropriateaccountdebit.CyberCashInc.isasmallstart-upcompanysetupinAugust,1994,inVirginia.CyberCashisdevel
