Marie was a young army recruit when she joined a small team dedicated to cracking the Nazi Enigma code.

Marie Bennett as she was in 1943

Many people say their efforts helped to shorten the war by at least two years.

Now, after years of silence, Marie is finally beginning to talk about the momentous work she undertook more than 50 years ago.

Code-breaker

The film Enigma, based on Robert Harris' best-selling book, chronicles British attempts to crack Enigma - the backbone of German military and intelligence communication.

Kate Winslet stars as Hester, a young code clerk working at Bletchley Park, and co-stars Dougray Scott, who plays a brilliant young code-breaker.

Everyone was in the same situation, we did not say things to each other or other civilians. We were told not to - 'careless talk costs lives' was the motto we upheld Marie Bennett

Marie Bennett was 20 years old when she was called for a mysterious interview, while working for the ATS, the women's branch of the Territorial Army. The young accounts clerk had no idea for what job she was being interviewed, but she knew it was top secret.

"The officers had Intelligence Corps badges and I recognised that and knew something was afoot. But I did not know what they did," she said.

Marie was sent back to her unit but was shortly recalled and sent to Leicester. Here she signed the Official Secrets Act and worked on sorting "incomprehensible" cards filled with groups of letters.

Nothing made sense until she later moved to Bletchley Park and found out the letters were call-signs, used during broadcasts on German radio stations. It was going to be her job to decipher them.

Darkness

Like Kate Winslet's character Hester, Marie was assigned to Hut 6 at Bletchley Park where she worked as a log reader.

"We worked eight hour shifts and two out of three of them were likely to be when it was dark," she recalled.

Marie Bennett today outside Hut 6 at Bletchley Park

"Everyone was in the same situation, we did not say things to each other or other civilians. We were told not to - 'careless talk costs lives' was the motto we upheld."

Many of Marie's co-workers were young like herself and lived at billeted addresses near the centre in Buckinghamshire. They shared both secrets and a life apart from the outside world.

"Everyone worked together for the end of the war. Our lives were kind of suspended until it ended.

"We had fun and went out together, to the theatre and to London.

Silence

"But when the War finished we just wanted to get on with our lives again and never talked about our work at Bletchley Park."

Marie kept her silence for more than 30 years, telling no one - not even her late husband Ben - about the crucial work. When Robert Harris wrote his book Enigma, on which the film is based, the veil of secrecy was lifted.

Code-breaking may have shortened the war

"I had not spoken about it for years and gradually I recalled it all again," said Marie, whose memory for detail is astoundingly vivid.

The movie, a British-made film produced by Mick Jagger, celebrates the success of the code-breakers.

Churchill himself dubbed the code-breakers "the geese who laid the golden eggs", and Marie played her part.

"Hut 6 was able to break a message because I told them what was in it," she recalled.

Every year, Marie organises a reunion of many of those who worked together at Bletchley Park. Some come from as far away as New Zealand and America to reunite.

Kate Winslet stars as Hester in Enigma

"It was one of the most interesting and memorable times of my life," said Marie, who became a teacher after the war ended.

"I've seen the film and I thought it was excellent. Some parts are different to what really happened but I enjoyed it and it's nice for my grandchildren to see," she said.

Enigma, which also stars Saffron Burrows, is released across the UK at the end of the month.