Jerzy Różycki was a Polish mathematician and cryptologist. A student of the Mathematical Institute at the University in Poznan, he was given in 1929, along with twenty-odd of his fellow-students, a rudimentary training in codebreaking during a special course, organized by the military. The real aim of the course was to find cryptological talents. Three of the students, Różycki, Marian Rejewski, and Henryk Zygalski were chosen. The most promising among them, Rejewski, was sent after his graduation for a one-year period of advanced study in actuarial mathematics to Goettingen.
In the autumn of 1930, a new branch of the Ciphers Office (Biuro Szyfrow) opened in utmost secrecy in Poznan and Różycki and Zygalski began to work there. It was located in a vault in the Army's regional command post in the outskirts of Poznan - a building built by Kaiser Wilhelm II as the official residence for the Crown Prince. They were later joined there by Rejewski.
In 1932, the group was moved to Warsaw where they began work as regular employees at the Cipher Bureau. It was there that they were given the task of breaking the code of the Enigma machine. Rejewski developed a scheme of decryption from a mathematical viewpoint. They were able to build replicas of the Enigma. With the help of these they began to decifer German military communications.
To facilitate decryption Rajewski designed an electromechanical programmable machine which he called 'Bomba' (Polish for bomb) because of its cylindrical shape and the bomb-like ticking noise it made. Zygalski, on the other hand developed a completely new method using perforated paper sheets
In 1934, the General Staff's Cipher Office established a new site for their German branch (BS-4) in the Kabaty Forest near Warsaw. It was at that location that on July 25, 1939, the Poles gave the French and the British replicas of Polish made Enigmas together with the drawings and information on the Enigma, Bomba and the decryption information. Later, when Germany invaded Poland in September, the group was ordered to evacuate to Rumania. Eluding the Rumanian authorities, they managed to contact the French who arranged for them to come to France. A cryptographic unit was organized in France and continued to function even after the fall of France. On 9 January 1942, Jerzy Rozycki died when the M/S "Lamoriciere," in which he was crossing the Mediterranean in from France to
Algeria, sunk near the Balearic Isles in a storm, possibly after hitting a mine.