Very cool, thanks for posting it NC.
In 1976 I became a history student after reading Anthony Cave Brown’s “Body Guard of Lies”. It dealt with the preparations for D-Day and the WWII sig/intel including Enigma. For 9 years after that, I studied this.
The impact on the war was Very significant.
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“It was not until 1974 the secret of Ultra was revealed to the public when GP Capt F W Winterbotham was permitted by the public to publish his book describing the key role in the distribution of Ultra Intelligence. Professor Harry Hinsley who himself worked at Bletchley Park gave his opinion that without Ultra intelligence the war could have gone on to 1948.”