Secret messages, encoded predictions, cryptic clues -- never have cryptogram puzzles been so popular, fueled by phenomena like The Da Vinci Code and Bible Code. From award-winning cryptographer and game developer Elonka Dunin, here is a major new collection of brain teasing cryptograms and other enciphered challenges to satisfy every level of puzzle aficionado. The Mammoth Book of Secret Codes and Cryptograms contains over 400 encoded puzzles, ranging from easy substitution puzzles and messages or quotations in code where each letter stands for another, to fiendishly difficult ciphers. This book also includes helpful tips and pointers, plus famous unsolved real-world cryptograms like the Dorabella cipher, Kryptos fourth section, Zodiac killer ciphers, Linear A, and Rongorongo script to ensure that the challenge never ends.