Georges Painvin

Georges Jean Painvin ([ʒɔʁʒ pɛ̃vɛ̃]; 28 January 1886 – 21 January 1980) was a French cryptanalyst during the First World War. His most notable achievement was the breaking of the ADFGVX cipher in June 1918.

Before the First World War, Painvin taught paleontology and geology as well as playing the cello as a hobby. He performed cryptanalytic work for the French army after a chance encounter with a member of the French Bureau de Chiffre.

In June 1918, the German army was preparing for a final push to cover the 100 kilometres that separated it from Paris. The Allies needed to know where the German attack would come. Painvin managed to break an ADFGVX enciphered message, which read: "Rush munitions. Even by day if not seen." This message indicated where the German offensive was to take place, and the allies managed to defeat the German attack. In attempting to break the ADFGVX cipher Painvin lost 15 kg in weight.

After the war, he returned to teaching and became president of several companies, as well as of the Paris Chamber of Commerce. He was made a chevalier of the Légion d'honneur, but was unable to speak about it for many years because of the secrecy that surrounded his work. He died in 1980.

• Singh, S. The Code Book, Fourth Estate, 1999. ISBN 1-85702-889-9