John Pryor

Researchers crack MI9 codes to reveal PoWs' wartime requests

Hidden messages locked in coded wartime letters have been revealed for the first time in 70 years by academics at Plymouth University.

Mathematicians, historians and geographers have worked together to crack codes used by MI9 to conceal information going in and out of prisoner of war camps across Europe during the Second World War.

They give a fascinating insight into how the...