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History of codes and ciphers--how they're made, how they're broken, and the many and fascinating roles they've played since the dawn of civilization in war, business, diplomacy, and espionage--updated with a new chapter on computer cryptography and the Ultra secret.
Originally published in the New Mathematical Library almost half a century ago, this book explains how to solve cryptograms based on elementary mathematical principles, starting with the Caesar cipher and building up to progressively more sophisticated substitution methods. Todd Feil has updated the book for the technological age by adding two new chapters covering RSA public-key cryptography, one-time pads, and pseudo-random-number generators.
Tour of the mathematics behind cryptography--the science of sending secret messages. Shows how mathematical principles underpin the ways that different codes and ciphers operate; discusses the majority of ancient and modern ciphers currently known.