PGP & GPG

16 Chapter 1

especially useful in an age when the written word was a mystery

to most people. These days, however, it would be less-than-

adequate protection against the prying eyes of anyone who

has passed third grade.

Ciphers

One type of code is the cipher, which conceals the contents of

a message by transforming each character in some way. One

cipher that most kids play with at one time or another is a code

that matches the letters in the alphabet to numbers (“A=1,

B=2, C=3,” and so on), with the text message then written as a

series of numbers instead of letters.

This is, however, a poor cipher for serious use. Not only is

it widely known, but ...