The award-winning New York Times bestseller about the American women who secretly served as codebreakers during World War II--a "prodigiously researched and eng

"As gripping as a good thriller." --The Washington Post Unpack the science of secrecy and discover the methods behind cryptography--the encoding and decoding of

Simply and clearly written book, filled with cartoons and easy-to-follow instructions, tells youngsters 8 and up how to break 6 different types of coded message