A history of codes and the methodologies for forming and breaking them, from ancient times to modern computers. It's 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...

Describes how the American military in World War II used a group of Navajo Indians to create an indecipherable code based on their native language.

Recruited by the U.S. Army and Navy from small towns and elite colleges, more than ten thousand women served as codebreakers during World War II. While their brothers and boyfriends took up arms, these women moved to Washington and learned the meticulous work of code-breaking. Their efforts shortened the war, saved countless lives, and gave them access to careers previously denied to them.

Examines the history of writing and provides instructions for making special inks, using various alphabets and codes, and creating personal seals and private letter drops.