英文版的。不要下错了。Secretwritingforthetransmissionofmessageshasbeenpracticedfornearly4,000years.AccordingtoDavidKahn,thegreathistorianofcryptology,thefirstexampleofanintentionallyalteredmessagecanbetracedtoatombinancientEgyptdatedabout1900b.c.Inthe40centuriessincethatevent,secretmessages