A Polish Enigma "double" was a machine produced by the Polish Cipher Bureau that replicated the German Enigma rotor cipher machine. The Enigma double was one result of Marian Rejewski's remarkable achievement of determining the wirings of the Enigma's rotors and reflectors. [1]
The Polish Cipher Bureau realized that the Germans were using a new cipher. The Germans had mistakenly shipped a cipher machine to Poland; their attempts to recover the shipment raised the suspicions of Polish customs, and the Cipher Bureau learned that the Germans were using Enigma machines. [2] [3] [4] [5] The Bureau purchased a commercial Enigma and attempted, but failed, to break the cipher.
In December 1932 the Cipher Bureau tasked Marian Rejewski with reconstructing the Enigma machine. A French spy had obtained some material about the Enigma, and the French had provided the material to the Polish Cipher Bureau. By then, for the purposes of the German military, the original commercial Enigma had been equipped with a plugboard. Rejewski made rapid progress and was able to determine the wirings of the military Enigma. The Bureau modified its commercial Enigma rotors, reflector, and internal wiring to match the military Enigma's.
The Cipher Bureau's commercial Enigma did not have a plugboard, but the plugboard could be simulated by relabeling the keys and lamps. [6] The result was the first Polish Enigma double.
In February 1933, the Polish Cipher Bureau ordered fifteen "doubles" of the military Enigma machine from the AVA Radio Manufacturing Company, in Warsaw. [7] Ultimately, about seventy such functional replicas were produced.
In August 1939, following a tripartite meeting of Polish, French, and British cryptologists at Warsaw on 25–26 July 1939 – during which the Poles had explained all their Enigma-decryption methods and equipment – two Enigma replicas were passed to Poland's allies, one sent to Paris and one to London. [8]
Earlier, German military Enigma traffic had totally defeated the French and British, and they had faced the prospect of being unable to read German communications during the coming war.
After Germany invaded Poland in September 1939 and key Polish Polish Cipher Bureau personnel had been evacuated to France, the Cipher Bureau resumed its interrupted work at PC Bruno outside Paris. The Poles had only three replica Enigmas to work with, [9] two secretly taken out of Poland during the evacuation, and the one that had been sent to France after the July 1939 Warsaw conference, and these were wearing out from round-the-clock use.
French Army intelligence officer Gustave Bertrand ordered parts for forty machines from a French precision-mechanics firm. Manufacture proceeded sluggishly, however, and it was only after the fall of France and the opening of underground work in southern France's Free Zone in October 1940 that four machines were finally assembled. [10]
| Methods and technology |
|---|
| Locations |
| Personnel |
Chief Gwido Langer German Section cryptologists Wiktor Michałowski Chief of Russian Section Jan Graliński Russian Section cryptologist Piotr Smoleński |
| The Enigma cipher machine |
|---|
 |
On the last Saturday in January 1929 an alert customs officer working in Warsaw had been about to process a heavy box when his suspicions were aroused by a request from the German Embassy. Apparently the box had been sent to Poland by mistake and a German Embassy official was requesting that it should be returned to Germany immediately. When the box was opened, an Enigma machine was found inside. The Polish General Staff's Cipher Bureau quickly called in two engineers to examine it.. This date is one year later than Rejewski's date. This reference also has the Polish Cipher Bureau receiving technical details of the Enigma from the French in December 1931 and September 1932.
The Enigma machine is a cipher device developed and used in the early- to mid-20th century to protect commercial, diplomatic, and military communication. It was employed extensively by Nazi Germany during World War II, in all branches of the German military. The Enigma machine was considered so secure that it was used to encipher the most top-secret messages.
Jerzy Witold Różycki was a Polish mathematician and cryptologist who worked at breaking German Enigma-machine ciphers before and during World War II.
Henryk Zygalski was a Polish mathematician and cryptologist who worked at breaking German Enigma-machine ciphers before and during World War II.
Hans-Thilo Schmidt codenamed Asché or Source D, was a spy who sold secrets about the German Enigma machine to the French during World War II. The materials he provided facilitated Polish mathematician Marian Rejewski's reconstruction of the wiring in the Enigma's rotors and reflector; thereafter the Poles were able to read a large proportion of Enigma-enciphered traffic.
The Cipher Bureau was the interwar Polish General Staff's Second Department's unit charged with SIGINT and both cryptography and cryptanalysis.
The bomba, or bomba kryptologiczna, was a special-purpose machine designed around October 1938 by Polish Cipher Bureau cryptologist Marian Rejewski to break German Enigma-machine ciphers.
Cryptanalysis of the Enigma ciphering system enabled the western Allies in World War II to read substantial amounts of Morse-coded radio communications of the Axis powers that had been enciphered using Enigma machines. This yielded military intelligence which, along with that from other decrypted Axis radio and teleprinter transmissions, was given the codename Ultra.
The method of Zygalski sheets was a cryptologic technique used by the Polish Cipher Bureau before and during World War II, and during the war also by British cryptologists at Bletchley Park, to decrypt messages enciphered on German Enigma machines.
Cadix was a World War II clandestine intelligence center at Uzès, in southern France, from September 1940 to 9 November 1942. During this period southern France was under the control of Vichy France and not occupied by Nazi Germany. At Cadix, the predominantly Polish team of cryptanalysts who had previously worked at PC Bruno was reassembled, and worked against German and other Axis ciphers, including the German Enigma machine cipher. Cadix shut down when Germany occupied southern France.
The cyclometer was a cryptologic device designed, "probably in 1934 or 1935," by Marian Rejewski of the Polish Cipher Bureau's German section (BS-4), to catalog the cycle structure of Enigma permutations, thereby facilitating the decryption of German Enigma ciphertext.
The Lacida, also called LCD, was a Polish rotor cipher machine. It was designed and produced before World War II by Poland's Cipher Bureau for prospective wartime use by Polish military higher commands. Lacida was also known as Crypto Machine during a TNMOC Virtual Talk.
Gustave Bertrand (1896–1976) was a French military intelligence officer who made a vital contribution to the decryption, by Poland's Cipher Bureau, of German Enigma ciphers, beginning in December 1932. This achievement would in turn lead to Britain's celebrated World War II Ultra operation.
Władysław Kozaczuk was a Polish Army colonel and a military and intelligence historian.
Richard Andrew Woytak was a Polish–American historian who specialized in European history of the Interbellum and World War II.
The card catalog, or "catalog of characteristics," in cryptography, was a system designed by Polish Cipher Bureau mathematician-cryptologist Marian Rejewski, and first completed about 1935 or 1936, to facilitate decrypting German Enigma ciphers.
Marian Adam Rejewski was a Polish mathematician and cryptologist who in late 1932 reconstructed the sight-unseen Nazi German military Enigma cipher machine, aided by limited documents obtained by French military intelligence. Over the next nearly seven years, Rejewski and fellow mathematician-cryptologists Jerzy Różycki and Henryk Zygalski developed and used techniques and equipment to decrypt the German machine ciphers, even as the Germans introduced modifications to their equipment and encryption procedures.
Ludomir Danilewicz (1905–1960) was a Polish engineer and, for some ten years before the outbreak of World War II, one of the four directors of the AVA Radio Company in Warsaw, Poland. AVA designed and built radio equipment for the Polish General Staff's Cipher Bureau, which was responsible for the radio communications of the General Staff's Oddział II.
Leonard Stanisław Danilewicz was a Polish engineer and, for some ten years before the outbreak of World War II, one of the four directors of the AVA Radio Company in Warsaw, Poland.
The AVA Radio Company was a Polish electronics firm founded in 1929 in Warsaw, Poland. AVA designed and built radio equipment for the Polish General Staff's Cipher Bureau, which was responsible for the radio communications of the General Staff's Oddział II.
Edward Fokczyński was one of the four directors of the AVA Radio Company, an electronics firm established in Warsaw, Poland, in 1929. AVA produced radio equipment for the Polish General Staff's Cipher Bureau, which was responsible for the radio communications of the General Staff's Intelligence Section.
