Armed with just a pencil and paper, suburban mother Elizebeth Friedman cracks the codes that bring down the mob, save countless lives in World War II, and prevent a Nazi invasion of America.

The desperate bid to break the complex coded messages of the Zodiac, America's most mysterious serial killer.

The US efforts to crack Japan's unbreakable WWII code following the horror of the attack on Pearl Harbour.

The deciphering of a mysterious ancient language and unlocking its secrets is a 50-year obsessive journey that rewrites history.

Experts reveal the highly encrypted phones that criminal gangs use to stay under the radar, and explain how the police are turning the phones against the crooks.

A look at America's Cold War code breakers charged with unravelling a seemingly un-crackable Soviet code and the uncovering of the Manhattan Project.