Georges Jean Painvin was a French

France

The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

 cryptanalyst during the First World War. His most notable achievement was the breaking of the ADFGVX cipher

ADFGVX cipher

In cryptography, the ADFGVX cipher was a field cipher used by the German Army during World War I. ADFGVX was in fact an extension of an earlier cipher called ADFGX. Invented by Colonel Fritz Nebel and introduced in March 1918, the cipher was a fractionating transposition cipher which combined a...

 in June 1918.

Before the First World War, Painvin taught paleontology

Paleontology

Paleontology "old, ancient", ὄν, ὀντ- "being, creature", and λόγος "speech, thought") is the study of prehistoric life. It includes the study of fossils to determine organisms' evolution and interactions with each other and their environments...

 and geology

Geology

Geology is the science comprising the study of solid Earth, the rocks of which it is composed, and the processes by which it evolves. Geology gives insight into the history of the Earth, as it provides the primary evidence for plate tectonics, the evolutionary history of life, and past climates...

. He performed cryptanalytic work for the French army after a chance encounter with a member of the French Bureau du Chiffre.

In June 1918, the German

Germany

Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

 army was preparing for a final push to cover the 100 kilometres that separated it from Paris

Paris

Paris is the capital and largest city in France, situated on the river Seine, in northern France, at the heart of the Île-de-France region...

. 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

Paris Chamber of Commerce

The Paris Chamber of Commerce is a Chamber of Commerce of the Paris region. It defends the interests of 310,000 corporations of the Paris, Hauts-de-Seine, Seine-Saint-Denis, and Val-de-Marne départements that create 20% of France's GDP.The CCIP was created on February 25, 1803 by Napoléon...

. He was made a chevalier of the Légion d'honneur

Légion d'honneur

The Legion of Honour, or in full the National Order of the Legion of Honour is a French order established by Napoleon Bonaparte, First Consul of the Consulat which succeeded to the First Republic, on 19 May 1802...

, but was unable to speak about it for many years because of the secrecy that surrounded his work. He died in 1980.