Thisisanupdateofthenowout-of-printComputerNetworkSecurity:TheoryandPractice,authoredbyJieWang,whichwaspublishedjointlybyHigherEducationPressandSpringerin2008.Theupdatedmaterialexpandsthefirsteditiontocoverdevelopmentssinceitscompletionin2008.Networksecurityisaconstantlyevolvingfield