Networksecurityconsistsofpoliciesandpracticestopreventandmonitor()access,misuse,modification,ordenialofacomputernetworkandnetwork-accessibleresources.Networksecurityinvolvestheauthorizationofaccesstodatainanetwork,whichiscontrolledbythenetwork(请作答此空).UserschooseorareassignedanIDandpasswordorotherauthenticatinginformationthatallowsthemtoaccesstoinformationandprogramswithintheirauthority.Networksecuritysecuresthenetwork,aswellasprotectingandoverseeingoperationsbeingdone.Themostcommonandsimplewayofprotectinganetworkresourceisbyassigningita()nameandacorrespondingpassword.Networksecuritystartswithauthentication.Onceauthenticateda()enforcespoliciessuchaswhatservicesareallowedtobeaccessedbythenetworkusers.Thougheffectivetopreventunauthorizedaccess,thiscomponentmayfailtocheckpotentiallyharmfulcontentsuchascomputer()orTrojansbeingtransmittedoverthenetwork
A.user B.agent C.server D.administrator正确答案D
