On January 9, 1942 French liner SS Lamoricière sank near the Balearic Islands. The ship was carrying 272 passengers, including Jerzy Różycki, Polish Cipher Bureau mathematician and cryptologist. He helped break the code of the German ENIGMA encryption device in 1939. During World War ll, Polish mathematicians handed the code over to British and French allies.
The victims of the French liner SS Lamoricière disaster (there were 212 passenger and 80 crew fatalities, and only 93 survivors) included three Polish cryptologists of the prewar Polish Cipher Bureau – Jerzy Różycki (of the Bureau’s German section), and Piotr Smoleński and Captain Jan Graliński (of the Bureau’s Russian section) – and a French officer accompanying the three Poles, Captain François Lane.
The deciphering of the mathematical basis of the Enigma, and the construction of a copy of the coding machine were the work of Polish mathematicians from the General Staff Code Bureau 4 (BS4): Marian Rejewski, Jerzy Różycki and Henryk Zygalski, who broke the Enigma secret in 1932 and started to read the German secret dispatches. Based on their research, Warsaw based AVA company built several copies of the Enigma machine in 1933. (Cryptologic Foundation)
In December 1932, the Bureau began breaking Germany’s Enigma ciphers. Over the next seven years, Polish cryptologists overcame the growing structural and operating complexities of the plugboard-equipped Enigma. The Bureau also broke Soviet cryptography.
Five weeks before the outbreak of World War II, on 25 July 1939, in Warsaw, the Polish Cipher Bureau revealed its Enigma-decryption techniques and equipment to representatives of French and British military intelligence, which had been unable to make any headway against Enigma. This Polish intelligence-and-technology transfer would give the Allies an unprecedented advantage (Ultra) in their ultimately victorious prosecution of World War II.