> For anyone who's interested in a nice discussion of the role 
> of cryptography in history and a good description of public 
> key cryptography I would recommend Simon Singh's "The 
> Codebreakers." A very entertaining piece of geek writing.

This is an *excellent* book.  It runs through the history of different
ciphers and how to break them.  Note that all 10 crypto challenges at the
end of the book were cracked last year.  Singh also wrote Fermat's Enigma,
which is an excellent book on Fermat's Last Theorem.  Interestingly enough,
the proof for Fermat's Enigma uses techniques that didn't exist back in
1630, so fermat's proof (if he truly had one) was most certainly quite
different.  If you're going on a book spree, get these two, you won't be
able to put them down.  Singh makes otherwise dry topics quite interesting
reading.

Jay