Under the Code Book: The Science of Secrecy from Ancient Egypt Quantum Cryptography, this version has been abridged and slightly simplified for a younger audience. From Julius Caesar to the 10th century Arab; of Mary Queen of Scots for "Alice and Bob"; of the German Enigma machine to the Navajo code speakers in World War II, Singh traces the use of codes to protect - and betrayed - confidentiality. Move right into the present, he describes how the Information Age has given a new set of challenges for cryptographers. Complex but very accessible, code book will make readers see the past - and future - in a new light.