Leonard Danilewicz

Leonard Stanisław Danilewicz (* around 1910, † after 1960) was a Polish engineer and radio amateur . Together with his older brother Ludomir Danilewicz as well as Edward Fokczyński and Antoni Palluth in 1929 he founded the Wytwórnia Radiotechniczna AVA (German: radio technology factory AVA) , a small company based in the Polish capital Warsaw , which specializes in the manufacture of special electromechanical and radio equipment for the Biuro Szyfrów (BS) (German: "Chiffrenbüro") of the Polish General Staff.

On the Polish Enigma replica, buttons (1), lamps (2) and sockets (7) were simply arranged alphabetically , as on the German Enigma-C .

The three letters "AVA" for their new company formed the young company founders as enthusiastic radio amateurs as a combination of their amateur radio callsigns "TPAV" by Leonard and Ludomir Danilewicz and "TPVA" by Palluth. At that time, in 1929, Leonard had not finished his engineering training, but was still a student at the Warsaw University of Technology . Later, in the 1930s, together with the three other company founders and a few other AVA employees, such as the precision mechanic Czesław Betlewski , he developed and manufactured important cryptanalytic machines for the BS cipher office , such as the Zyklometer and the Bomba , which were used against the German Enigma machine . They also made replicas of the German machine .

Leonard was a very talented high-frequency technician and developed an early form of frequency hopping , in which a transmission signal is secretly keyed in frequency in order to make radio detection and radio location more difficult. In September 1939 he witnessed the invasion of the Wehrmacht during an attack on Poland at the beginning of the Second World War. Like the other employees of the AVA plant and the BS , he fled from the advancing German troops. Like most of his colleagues, he probably went first via Romania to France and finally to England. Leonard and his brother Ludomir survived the war. There is a joint US patent 3,143,290 of the Danilewicz brothers with the title "Rotary Converter" from August 4, 1964, in which the London district of Ruislip is specified as his place of residence .

literature

• Friedrich L. Bauer : Deciphered Secrets. Methods and maxims of cryptology. 3rd, revised and expanded edition. Springer, Berlin et al. 2000, ISBN 3-540-67931-6 .
• David Kahn : The Code Breakers - The Story of Secret Writing . Macmillan USA, Reissue 1974, ISBN 0-02-560460-0 .
• David Kahn: Seizing the Enigma - The Race to Break the German U-Boat Codes, 1939-1943 . Naval Institute Press, Annapolis, MD, USA, 2012, ISBN 978-1-59114-807-4 .
• Władysław Kozaczuk : Enigma - How the German Machine Cipher Was Broken, and How It Was Read by the Allies in World War Two . Edited and translated by Christopher Kasparek, Frederick, MD, University Publications of America, 1984, ISBN 0-89093-547-5 .
• Władysław Kozaczuk, Jerzy Straszak, Enigma - How the Poles Broke the Nazi Code . Hippocrene Books, 2004, ISBN 0-7818-0941-X .
• Władysław Kozaczuk: Secret Operation Wicher . Bernard et al. Graefe, Koblenz 1989, Karl Müller, Erlangen 1999, ISBN 3-7637-5868-2 , ISBN 3-86070-803-1 .
• Władysław Kozaczuk: Under the spell of Enigma . Military publishing house, Berlin 1987, ISBN 3-327-00423-4 .
• Hugh Sebag-Montefiore : Enigma - The battle for the code . Cassell Military Paperbacks, London 2004, ISBN 0-304-36662-5 .

Individual evidence

1. ↑ Chris Christensen: Review of IEEE Milestone Award to the Polish Cipher Bureau for `` The First Breaking of Enigma Code '' . Cryptologia . Rose-Hulman Institute of Technology. Taylor & Francis, Philadelphia PA 39.2015,2, p. 185. ISSN  0161-1194 .
2. ↑ David Kahn: Seizing the Enigma - The Race to Break the German U-Boat codes 1939 -1943 . Naval Institute Press, Annapolis, MD, USA, 2012, p. 81. ISBN 978-1-59114-807-4 .