Just finished "The Codebreakers" by David Kahn. From now on this book ought to be given to students, and perhaps have a few new chapters added. Very interesting and gave me a perspective on how information is affecting all of us.
It took a while getting through, but then again, I'm not used to read that kind of english terminology.
"The Codebreakers The Story of Secret Writing (ISBN 0-684-83130-9) is a book by David Kahn, published in 1967 comprehensively chronicling the history of cryptography from ancient Egypt to the time of its writing. The United States government attempted to have the book altered before publication, and succeeded in part."
Wikipedia
Interesting that you liked that. You may be mathy. I got into the Voynich Manuscript mystery (14th-15th century illustrated coded manuscript) and the book "Codebreakers" was highly recommended. I'm more interested in the message in the clear and am not especially mathy, so I think I'll read a couple more Voynich works and let it go.