It is known as the science of secrecy. Cryptography: the encoding and decoding of private information. And it is history's most fascinating story of intrigue and cunning. From Julius Caesar and his Caesar Cipher to the code used by Mary Queen of Scots and her conspiracy to the use of the Engima machine during the Second World War, Simon Singh follows the evolution of secret writing. Accessible, compelling, and timely, this international bestseller, now adapted for young people, is sure to make readers see the past and the future - in a whole new way....