Enigma, or the Biggest Secret of World War II
The cracking of the secret Enigma code - the German coded communications system used by all types of armed forces - was one of the greatest achievements of Polish cryptologists in the 20th century. It significantly influenced the outcome of World War II: it enabled the discovery of the times of air raids during the Battle of Britain and the movements of German U-boats and Kriegsmarine ships; it facilitated the defeat of field marshal Rommel in Africa and the Allies' activities in Western Europe. Passing on the secrets of Japanese Enigma to the Americans enabled the decoding of the "Purple" machine code, deciphering the plans to attack Midway and winning the battle for the domination of the Coral Sea and the Pacific Ocean.
The Germans used Enigma until the very end of World War II convinced that no one could discover its secret.
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. Marian Rejewski constructed the so-called cyclometer, which solved the problem of Enigma's constantly changing keys, rotating disks and electrical connections, and the so-called cryptological bomb shortened the period of deciphering the changing coding rules. During a meeting at the Code Bureau in Kabaty Woods in July 1939, delegations of French and British cryptologists familiarized themselves with the achievements of the Polish mathematicians and received copies of the military version of the Enigma coding machine together with its construction plans, as well as the cryptological bomb and perforated sheets.
After the war broke out, 15 Polish cryptologists from BS4 were transferred to France where they cooperated with the French intelligence until November 1942, working out the subsequent modifications of Enigma.
Deciphered materials were forwarded to London and the intelligence center at Bletchley. After German occupation of the southern France, majority of them went to Great Britain via Spain.
The British, however, did not take advantage of the skills of Polish specialists.