Simon Singh offers in this book a sweeping view of the subject of encryption as well as its more dramatic effects on the outcome of wars, monarchies, and individual lives.

March 1943, the war hangs in the balance, and at Bletchley Park a brilliant young codebreaker is facing a double nightmare. The Germans have changed their U-boat Enigma code, threatening a massive Allied defeat. As suspicion grows that there may be a spy inside Bletchley, Jericho's girlfriend suddenly disappears.

Beautiful young don Catherine Donovan refuses to believe the official verdict - especially after she received a cryptic note sent just before the professor's death, along with a collection of priceless antique maps. Teaming up with classicist James Rutherford, she embarks on a journey that takes them from the dreaming spires of Oxford to the ancient wonders of Peru and Egypt. With a deeply sinister organisation determined to stop them, can Catherine...

Using recently declassified information, this is the untold story of Bletchley Park - the invention of the world's first true computer: Colossus, which revealed key information about the Third Reich strategy and high command structures. Publication ties in with the 60th anniversary of the end of WWII.

In 'Secrets at Bletchley Park' by Margaret Dickinson, two young women from very different backgrounds meet in the Second World War and are plunged into a life where security and discretion are paramount. But both have secrets of their own to hide.

'Delusions of Intelligence' analyses the characteristics that allowed the allies SIGINT (signals intelligence) success and that fostered German blindness to the compromise of the Enigma coding system.

The wartime secrets of the British codebreakers based at Bletchley Park continue to be revealed. In this book, Michael Smith examines how Japan's codes were broken, and the consequences of this for the Second World War.

This is a history of Colossus, the world's first fully-functioning electronic, digital computer that was built in the Second World War for codebreaking purposes. It includes only recently de-classified information.

Patricia and Jean Owtram are possibly the only living sisters to have signed the wartime Official Secrets act. Raised in a Lancashire country house in the 1920s, the family takes in two Austrian Jewish refugees, and the sisters quickly become fluent in German - which will go on to shape their roles forever.

Historian and broadcaster Tessa Dunlop tells the story of the women of Bletchley Park, through exclusive and unprecedented access to the women themselves.