«The Story of Codebreaking» by Nigel Cawthorne

'No wonder that Churchill described this effort as "Britain's secret weapon," a weapon far more effective than the buzz bombs and the rockets that Wernher von Braun designed for a German victory, a weapon absolutely decisive, in the judgement of many, in winning the war for the Allies.'
Peter Hilton, mathematician and codebreaker, 1923-2010, about the team at Bletchley Park

The Story of Codebreaking begins with the hieroglyphics of Ancient Egypt and weaves its way stealthily through history to the present day, where computer code is fundamental to all of our online activities. It is a tale of ordinary people rising to the challenge of extraordinary circumstances and shows how, through a combination of intelligence, grit, hard work and (occasionally) sheer good fortune, codebreakers have often saved lives and sometimes even changed the course of history.

Find out how Mary Queen of Scots smuggled cryptic messages to her accomplices when she was plotting against her cousin Elizabeth I, or discover the methods used by codebreakers during World Wars I and II, most significantly those who cracked Enigma and intercepted Japanese naval messages prior to Pearl Harbor. The sheer doggedness of those who unravelled the Enigma code is thought to have shortened World War II by almost two years.

To break a code, you have to put yourself in the mind of your enemy in order to probe the strengths and weaknesses of their systems. It's a game of bluff and doublebluff. The Story of Codebreaking describes undercover operations, power struggles, secret alliances, and brilliant feats of teamwork. Those who invent codes and those who break them are remarkable, indefatigable characters. This is their story.

Topics include:

Ancient ciphers and the art of encoding
Early spies, subterfuge and skytales
The making and breaking of Enigma
Japanese naval codes in World War II
Cold War cryptography