A handbook for the budding cryptographer including codes and ciphers, invisible inks, concealment techniques, spy stories and some history.

"A nonfiction manuscript for young readers about a group of Allied spies and codebreakers that cracked the Nazis's infamous cypher, allowing them to read secret military messages and turn the tide of World War II. During WWII, as the Germans waged war, every Nazi plan, every attack, was sent over radio. But to the Allies listening in, the messages sounded like gibberish. The communications were encoded with a powerful cypher-unless you could unlock...

"By the time the United States joined the Second World War in 1941, the fight against Nazi and Axis powers had already been under way for two years. In order to win the war and protect its soldiers, the US Marines recruited twenty-nine Navajo men to create a secret code that could be used to send military messages quickly and safely across battlefields. Author James Buckley Jr. explains how these brave and intelligent men developed their amazing code,...