The bomba kryptologiczna, which can be translated as a cryptologic bomb was a special machine designed by Polish mathematician Marian Rejewski, with the help of colleague Henryk Zygalski. Its purpose was to decipher German communication on Enigma during World War II.
So many people are intrigued as to why this machine was named a bomb, however, the origin of the name is not clearly known. According to Polish army officer and engineer Tadeusz Lisicki (who reportedly knew Henryk Zygalski during wartime Britain), the youngest of the three Enigma cryptologists, Jerzy Rozycki (who died in January 1942 after a passenger ship sank in the Mediterranean), named the machine after an ice cream dessert of the same name – Bomba. However, most people denounce this story as only a myth since Lisicki did not personally know Rozycki. On the other hand, Marian Rejewski says the machine was named a “bomb” for lack of a better name or idea.
During world war II the German military used an Enigma machine to communicate. It was essential for those fighting against German to decipher this encrypted information, however, the complex keying procedures of the Enigma made this task daunting.
To break an encrypted message, the polish intelligence had to check each of the daily message keys and there were thousands of possibilities for the keys. Rejewski was able to speed up the process by inventing the bomba kryptologicza.
In 1938, using information availed by some of the cryptographic malpractices of the German Enigma, Marian Rejewski, was able to understand the internal wirings of the Enigma. He went on to reconstruct the logical structure of the machine. Only general traits of the device were suspected, taken from the commercial version of the Enigma, which the Germans were using for diplomatic communication. The military variants were quite different.