Of the 10,000-plus staff at the Government Code and Cypher School during World War II, two-thirds were female. Three veteran servicewomen explain what life was like as part of the code-breaking operation during World War II.

"I was given one sentence, 'We are breaking German codes, end of story'."

It was Ruth Bourne's first job out of college, when, like thousands of other young British women during World War II, she was recruited to aid the Allied cipher-breaking efforts at Bletchley Park.

Today, the mansion in the heart of the southeast English countryside is famous for being where the brilliant mathematician Alan Turing cracked the Nazi's Enigma code.