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Previous: fsqFsHn sGGousG  Introduction to Cryptography  If some
information is meant to be kept private, the best means is to
keep it well hidden. This is not, of course, always possible.
One way around this is to hide the information or message in
plain sight, that is, encode it in some way so that even if it
is seen, it will be unreadable. The study of such encoding
processes is called Cryptography4.1. The name ``Cryptography''
comes from the Greek words kryptos ( $ \kappa$$ \rho$$ \nu$$
\pi$$ \tau$o$ \sigma$), meaning ``hidden'' or secret, and
graphia ( $ \gamma$$ \rho$$ \alpha$$ \phi$$ \iota$$ \alpha$),
meaning writing.  Since ancient times, cryptography has been a
part of military and governmental communications. More recently
it has become part of nearly everyone's life because of the
Internet, electronic banking, and so on.  The usual jargon is as
follows: the message you want to hide is called the plaintext,
and the act of encoding it is calle