An introduction to "just enough" cryptography can still be quite a bit. This series of pages is broken into several topics. This first page is an overview, so you can see where we're going. You might know some of the pieces and want to jump ahead, but if this is your first look at these vital information security tools, it will help if you've seen the road map.
If you're ready, start learning about cryptography here
"This Arte of Cypheringe, hath for
Relative, an Art of Discypheringe;
by supposition unprofitable;
but, as things are, of great use.
For suppose that Cyphars were well
managed, there bee Multitudes of them
which exclude the Discypherer.
But the rawness and unskillfulnesse of
Secretaries, and Clerks, in the Courts
of Princes, is such that many times
the greatest matters are committed
to futile and weake Cyphers."
— Roger Bacon, De Augmentis Scientaiarum, 1623, London
"The man is insane who writes a secret
in any other way than one which will
conceal it from the vulgar and make
it intelligible only with difficulty
even to scientific men and
— Roger Bacon, Epistle on the Nullity of Magic, eighth chapter
When cryptography is outlawed,
bayl bhgynjf jvyy unir cevinpl.
— Many people on the Internet, in an extremely simple rot13 substitution cipher.