Biuro Szyfrów

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Template:Cipher Bureau main The Biuro Szyfrów (Template:IPAudio, Polish for "Cipher Bureau") was the Polish agency concerned with cryptology between World Wars I and II. The Bureau enjoyed notable successes against Soviet cryptography during the Polish-Soviet War, helping to preserve Poland's independence. Beginning in December 1932, the Cipher Bureau broke the German Enigma cipher and overcame the ever-growing structural and operating complexities of the evolving Enigma machine.

The Cipher Bureau's purview included both ciphers and codes. In loose Polish parlance, "cipher" (szyfr) is used to refer to either of these two principal categories of cryptography.


According to Bury (2004), a Polish Army "Cipher Section" (Sekcja Szyfrów) was created by Lt. Józef Stanslicki on May 8, 1919, and a few months later was renamed the "Cipher Bureau" (Biuro Szyfrów). Reporting to the Polish General Staff, it contributed substantially to Józef Piłsudski's defense of Poland in the Polish-Soviet War (1919-1921). Soviet military cryptography at the time was primitive and, when actually used, was further weakened by Soviet cipher clerks' neglect of elementary security practices.

The commonest Russian cipher was broken as early as 1919 by a young mathematician, Stefan Mazurkiewicz, later vice rector of Warsaw University. Thanks to this, orders issued by Soviet commander Mikhail Tukhachevski's staff were known to Polish Army leaders. Under the auspices of Col. Tadeusz Schaetzel, chief of the Polish General Staff's Section II (Intelligence), the Polish cryptologists enjoyed generous support as they labored at Warsaw's radio station WAR, one of two Polish long-range radio transmitters. Thanks to breaking Russian ciphers, the Poles discovered a large gap in the Red Army's left flank and drove a wedge into that gap during the August 1920 Battle of Warsaw. The cryptologists also subsequently determined that the 4th Red Army had lost contact with its headquarters; as a result, it continued its drive into Pomerania (Pomorze), on the Baltic coast — even after the bulk of Bolshevik forces were in retreat — and was completely destroyed.

According to Polish military historian Władysław Kozaczuk (1984 Enigma, p. 23, note 6), the Polish General Staff's Cipher Bureau was formed in mid-1931 by merger of the Radio Intelligence Office (Referat Radiowywiadu) and the Polish-Cryptography Office (Referat Szyfrów Własnych). Between 1932 and 1936, the Cipher Bureau took over additional responsibilities, including radio communications among military-intelligence posts in Poland and abroad and radio counterintelligence (mobile direction-finding-and-intercept stations for uncovering foreign-intelligence and fifth-column transmitters operating in Poland).

File:Cyclometer machine Drawing from M Rejewski’s papers.jpg
Cyclometer (1934). Diagram from Marian Rejewski’s papers. 1: Rotor lid closed. 2: Rotor lid open. 3: Rheostat. 4: Glowlamps. 5: Switches. 6: Letters.

Major Gwido Langer, after a tour of duty as chief of staff of the 1st Legions Infantry Division, on January 15, 1929, became chief of the Radio Intelligence Office, and subsequently of the Cipher Bureau. The Bureau's deputy chief, and chief of its German section (BS-4), was Capt. Maksymilian Ciężki.

In 1929, while the Cipher Bureau's predecessor was headed by Major Franciszek Pokorny, Ciężki, Pokorny and civilian Bureau employee Antoni Palluth taught a secret cryptology course at Poznań University for selected mathematics students. (Marian Rejewski later discovered in France, during World War II, that the entire course had been taught from French General Marcel Givièrge's book, Cours de cryptographie, published in 1925.)

Subsequently, in September 1932, Ciężki hired for the Cipher Bureau three young graduates of the course: Marian Rejewski, Jerzy Różycki and Henryk Zygalski.

Rejewski made one of the great advances in cryptology in December 1932 by applying mathematicsgroup theory — to breaking the German armed forces' Enigma machine ciphers (the Navy had adopted a modified civilian Enigma machine in 1926, the Army in 1928). The Bureau commissioned the AVA Radio Manufacturing Company, co-owned by Palluth, to build "doubles" of the German Enigma to Rejewski's specifications, as well as cryptologic devices such as Rejewski's "cyclometer" and "cryptologic bomb." "Zygalski sheets" were produced by Cipher Bureau personnel.

The Cipher Bureau's German section, BS-4, was housed in the Polish General Staff building (the stately 18th-century "Saxon Palace") in Warsaw until 1937. That year, for reasons of space and security, BS-4 moved into specially constructed new facilities in the Kabaty Woods near Pyry, south of Warsaw.

File:Kabaty Biuro Szyfrow.jpg
Cipher Bureau building constructed in 1937 in the Kabaty Woods, south of Warsaw.

It was there, on July 25, 1939, with World War II looming only five weeks off, that the Cipher Bureau's chiefs, Lt. Col. Gwido Langer and Major Maksymilian Ciężki, the three civilian mathematician-cryptologists, and Col. Stefan Mayer (Polish General Staff intelligence chief), on General Staff instructions, revealed Poland's Enigma-decryption achievements to intelligence representatives of France (Major Gustave Bertrand, the French radio-intelligence and cryptology chief, and Capt. Henri Braquenié of the French Air Force staff) and Britain (Commander Alastair Denniston, chief of Britain's Government Code and Cypher School; Alfred Dillwyn Knox, chief British cryptologist; and Commander Humphrey Sandwith, chief of the Royal Navy's intercept and direction-finding stations).

File:Gwido Langer Gustave Bertrand Kenneth McFarlan.jpg
At PC Bruno, outside Paris, France, during the Phony War (October 1939 - May 1940):
From left: Polish Lt. Col. Gwido Langer, French Major Gustave Bertrand, and British liaison officer Capt. Kenneth McFarlan.
File:‘Cryptologic bomb’ machine - drawing from M.Rejewski’s papers.jpg
Cryptologic bomb (1938). Diagram from Marian Rejewski's papers. 1: Rotors (for clarity, only one 3-rotor set is shown). 2: Electric motor. 3: Switches.

Rejewski had ultimately solved a crucial element in the Enigma machine's structure, the wiring of the letters of the alphabet into the entry drum, with the inspired guess that they might be wired in in simple alphabetical order. Now, at the trilateral meeting — Rejewski was later to recount — "the first question that... Dillwyn Knox asked was: 'What are the connections in the entry drum?'" Knox was mortified to learn how simple the answer was.

The Poles' gift, to their western Allies, of Enigma decryption, a little over a month before the outbreak of World War II, came not a moment too soon. Former Bletchley Park mathematician-cryptologist Gordon Welchman has written: "Ultra [the British Enigma-decryption operation] would never have gotten off the ground if we had not learned from the Poles, in the nick of time, the details both of the German military... Enigma machine, and of the operating procedures that were in use." Britain's Prime Minister Winston Churchill was to tell King George VI after the war: "It was thanks to Ultra that we won the war."

On September 5, 1939, as it became clear that Poland was unlikely to halt the German invasion, BS-4 received orders to destroy part of its files and evacuate essential personnel. On September 17, upon the Soviet Army's entry into eastern Poland, they crossed the border, with other Polish military and government personnel, into Romania. Subsequently they made their way to France, where at PC Bruno, outside Paris, they continued breaking German Enigma ciphers in collaboration with the Ultra operation at Bletchley Park, fifty miles northwest of London, England. In the interest of security, the allied cryptological services corresponded, by teletype, in Enigma. Braquenié often closed messages with a "Heil Hitler!"

Following the capitulation of France to Germany in June 1940, the Poles continued their cryptologic work in the unoccupied "Free Zone" of southern France under the sponsorship of Gustave Bertrand until southern, Vichy France was occupied by the Germans in November 1942.

Before the war, as mentioned, Antoni Palluth (a Warsaw Polytechnic civil-engineering graduate who had been a lecturer in the secret Poznań University cryptology course), had been co-owner of AVA, a radio-manufacturing enterprise that produced equipment for the Cipher Bureau. Under German occupation, some AVA workers were interrogated by the Germans but managed to say nothing that might lead them to suspect that the Enigma cipher had been compromised.

See also


  • 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.
  • Jan Bury, "Polish Codebreaking during the Russo-Polish War of 1919–1920," Cryptologia, vol. 28, no. 3 (July 2004), pp. 193–203.

External links

pl:Biuro Szyfrów