Lifting the veil of secrecy on the intelligence service
10 September 2013 Last updated at 07:10 BST
For the first time a former director of GCHQ talks about his time working in the UK government's intelligence service in Cheltenham.
Sir Arthur Bonsall is a former director of GCHQ who lived a life in the shadows for almost 40 years.
He was recruited to the government's secret code breaking service in 1939 to undertake confidential war work at Bletchley Park.
Sir Arthur rose through the ranks and became the sixth director at GCHQ in 1973 and has never spoken on camera about his work until now.
Inside Out's Steve Knibbs has been allowed extremely rare access to the GCHQ building in Cheltenham to speak with him.