The Enigma cipher machine

Enigma machine Enigma rotor details Cryptanalysis of the Enigma Cipher Bureau Perforated sheets Clock Grill Bomba Polish Enigma doubles Cyclometer Bletchley Park Banburismus Herivel tip Bombe Hut 6 Hut 8 PC Bruno Ultra

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The Biuro Szyfrów (['bjurɔ 'ʃɨfruf] (help·info), Polish for "Cipher Bureau") was the Polish interwar agency charged with both cryptography (the use of ciphers and codes) and cryptanalysis (the "breaking" of ciphers and codes).

A Polish Army "Cipher Section" (Sekcja Szyfrów) was created by Lt. Józef Serafin Stanslicki on May 8, 1919,^[1] and a few months later was renamed the "Cipher Bureau" (Biuro Szyfrów). It reported to the Polish General Staff, and contributed substantially to Poland's defense by Józef Piłsudski's forces during the Polish-Soviet War of 1919-21, thereby helping preserve Poland's independence, just recently regained in the wake of World War I.

Beginning in December 1932, the Cipher Bureau broke the German Enigma machine cipher and overcame the ever-growing structural and operating complexities of the evolving plugboard-equipped Enigma, which would be the main German cipher device during World War II.

The Cipher Bureau's purview included both ciphers and codes. In loose Polish parlance, the term "cipher" ("szyfr") refers to both these two principal categories of cryptography. (The opposite is the practice in English, which loosely refers to both codes and ciphers as "codes.")

Polish-Soviet War

Main article: Polish-Soviet War

During the Polish-Soviet War of 1919–21, some one hundred Russian ciphers were broken by a sizable cadre of Polish cryptologists who included Army Lt. Jan Kowalewski and three famous professors of mathematics: Stefan Mazurkiewicz, Wacław Sierpiński and Stanisław Leśniewski.^[2]

During the Polish-Soviet War, Russian army staffs followed the same signals-security procedures as had Tsarist army staffs during World War I. As a result, the Polish army was kept informed by Russian radiotelegraphic stations about the movements of Russian armies and their intentions and operational orders. The Russian staffs, according to Polish Colonel Mieczysław Ścieżyński, "had not the slightest hesitation about sending any and all messages of an operational nature by means of radiotelegraphy; there were periods during the war when, for purposes of operational communications and for purposes of command by higher staffs, no other means of communication whatever were used, messages being transmitted either entirely ["in clear," or plaintext or encrypted by means of such an incredibly uncomplicated system that for our trained specialists reading the messages was child's play. The same held for the chitchat of personnel at radiotelegraphic stations, where discipline was disastrously lax."^[3]

In the crucial month of August 1920 alone, Polish cryptologists decrypted 410 signals: from Soviet General Mikhail Tukhachevski, commander of the northern front; from Leon Trotsky, Soviet commissar of war; from commanders of armies, e.g. the commander of the IV Army, Sergieyev; the commander of the Horse Army, Semyon Budionny; the commander of the 3 Cavalry Corps, Gaya; from the staffs of the XII, XV and XVI Armies; from the staffs of the Mozyr Group [named after the Belarussian city]; the Zolochiv Group [after the Ukrainian town]; the Yakir Group [after General Iona Emmanuilovich Yakir; from the 2, 4, 7, 10, 11, 12, 16, 17, 18, 24, 27, 41, 44, 45, 53, 54, 58 and 60 Infantry Divisions; from the 8 Cavalry Division, etc.^[4]

The intercepts were as a rule decrypted the same day, at latest the next day, and were immediately sent to the Polish General Staff's Section II (Intelligence) and operational section. The more important signals were read in their entirety by the Chief of the General Staff, and even by the Commander in Chief, Marshal Józef Piłsudski.^[5]

Interception and reading of the signals provided Polish intelligence with entire Russian operational orders. The Poles were able to follow the whole operation of Budionny's Horse Army in the second half of August 1920 with incredible precision, just by monitoring his radiotelegraphic correspondence with Tukhachevsky, including the famous and historic conflict between the two Russian commanders.^[6]

The intercepts even included an order from Trotsky to the revolutionary council of war of the Western Front, confirming Tukhachevsky's operational orders, thus giving them the authority of the supreme chief of the Soviet armed forces.^[7]

An entire operational order from Tukhachevsky to Budionny was intercepted on August 19 and read on August 20, stating the tasks of all of Tukhachevsky's armies, of which only the essence had previously been known.^[8]

Ścieżyński surmises that the Soviets must likewise have intercepted Polish operational signals; but he doubts that this would have availed them much since Polish cryptography "stood abreast of modern cryptography" and since only a small number of Polish higher headquarters were equipped with radio stations, of which there was a great shortage; and finally, Polish headquarters were more cautious than the Russians and almost every Polish division had the use of a land line.^[9]

Polish cryptologists enjoyed generous support under the command of Col. Tadeusz Schaetzel, chief of the Polish General Staff's Section II (Intelligence). They worked at Warsaw's radio station WAR, one of two Polish long-range radio transmitters at the time.

The Polish cryptologists' work led, among many other things, to discovery of a large gap on the Red Army's left flank, which enabled Poland's Marshal Józef Piłsudski to drive a war-winning wedge into that gap during the August 1920 Battle of Warsaw.^[10]

Grzegorz Nowik states that the discovery of the Cipher Bureau's archives, decades after the Polish-Soviet War, has demonstrated

that... radio intelligence... furnished [the Polish Commander-in-Chief, Józef Piłsudski, in the years 1919-1920, with the most complete and most current intelligence on all aspects of the functioning of the Red Army, especially of units operating on the anti-Polish front, that it was radio intelligence that to a large degree determined the course of all the military operations conducted by Poland in 1920 — from the January fighting at Ovruch, through the March operation against Mozyr and Kyiv, the April operation in Ukraine, the battles with Tukhachevsky's first and second offensives in Belarus, the battles with Budionny's Cavalry Army, the Battle of Brody, to the Battles of Warsaw, Lwów and the Niemen.^[11]

Cipher Bureau

In mid-1931, the Polish General Staff's Cipher Bureau was formed by merger of the Radio-Intelligence Office (Referat Radiowywiadu) and the Polish-Cryptography Office (Referat Szyfrów Własnych).^[12]

Between 1932 and 1936, the Cipher Bureau took on additional responsibilities, including radio communications between military-intelligence posts in Poland and abroad, as well as radio counterintelligence (mobile direction-finding and intercept stations for the locating and traffic-analysis of spy and fifth-column transmitters operating in Poland).^[13]

Stalking Enigma

General Staff building (Saxon Palace). Arcade shelters Tomb of the Unknown Soldier, before which stands Thorvaldsen's equestrian statue of Prince Józef Poniatowski. In this building in 1932 the Cipher Bureau broke the plugboard military Enigma, which would be the main German cipher device during World War II.

In late 1927 or early 1928, there arrived at the Warsaw Customs Office from Germany a package that, according to the accompanying declaration, was supposed to contain radio equipment. The German firm's representative strenuously demanded that the package be returned to Germany even before going through customs, as it had been shipped with other equipment by mistake. His insistent demands alerted the customs officials, who notified the Polish General Staff's Cipher Bureau, which took a keen interest in new developments in radio technology. And since it happened to be a Saturday afternoon, the Bureau's experts had ample time to look into the matter. They carefully opened the box and found that it did not, in fact, contain radio equipment but a cipher machine. They examined the machine minutely, then put it back into the box.^[14]

Rejewski comments that the cipher machine may be surmised to have been a commercial-model Enigma, since at that time the military model had not yet been devised. "Hence this trivial episode was of no practical importance, though it does fix the date at which the Cipher Bureau's interest in the Enigma machine began" — manifested, initially, in the entirely legal acquisition of a single commercial-model Enigma.^[15]

On July 15, 1928, the first German machine-enciphered messages were broadcast by German military radio stations. Polish monitoring stations began intercepting them, and Polish cryptologists in the Cipher Bureau's German section were instructed to try to read them. The effort was fruitless, however, and was eventually abandoned. There remained very slight evidence of that effort, in the form of a few densely written-over sheets of paper, and also the commercial-model Enigma machine.^[16]

On January 15, 1929, Major Gwido Langer, after a tour of duty as chief of staff of the 1st Legion Infantry Division, became chief of the Radio-Intelligence Office, and subsequently of the Cipher Bureau.^[17] The Bureau's deputy chief, and the chief of its German section (BS-4), was Captain Maksymilian Ciężki.

In 1929, while the Cipher Bureau's predecessor agency was still headed by Major Franciszek Pokorny (a relative of the outstanding World War I Austrian Army cryptologist, Captain Herman Pokorny^[18]), Ciężki, Franciszek Pokorny and a civilian Bureau employee, Antoni Palluth, taught a secret cryptology course at Poznań University for selected mathematics students. Over ten years later, during World War II while in France, one of the students, Marian Rejewski, would discover that the entire course had been taught from French General Marcel Givièrge's book, Cours de cryptographie, published in 1925.^[19]

In September 1932, Ciężki hired three young graduates of the Poznań course to be Bureau staff members: Marian Rejewski, Jerzy Różycki and Henryk Zygalski.^[20]

Enigma solved

Cyclometer (1934). 1: Rotor lid closed, 2: Rotor lid open, 3: Rheostat, 4: Glowlamp, 5: Switches, 6: Letters

Rejewski made in December 1932, according to historian David Kahn, one of the greatest advances in cryptologic history by applying pure mathematics — group theory — to breaking the German armed forces' Enigma machine ciphers.^[21] (The Navy had adopted a modified civilian Enigma machine in 1926, the Army — in 1928.^[22])

The Cipher Bureau commissioned the AVA Radio Manufacturing Company, co-owned by Antoni Palluth, to build "doubles" of the German Enigma to Rejewski's specifications.^[23]

AVA subsequently also constructed cryptologic devices such as Rejewski's "cyclometer" and "cryptologic bomb."^[24] "Zygalski sheets," on the other hand, were produced at the Cipher Bureau itself.

A Zygalski (perforated) sheet (1938).

In January 1938, Colonel Stefan Mayer directed that statistics be compiled for a two-week period, comparing the numbers of Enigma messages solved, to Enigma intercepts. The ratio came to 75 percent. "Nor," Marian Rejewski has commented, "were those 75 percent... the limit of our possibilities. With slightly augmented personnel, we might have attained about 90 percent... read. But a certain amount of cipher material... due to faulty transmission or... reception, or to various other causes, always remains unread..."^[25]

Cryptologic bomb (1938). 1: Rotors (only one 3-rotor set is shown). 2: Electric motor. 3: Switches.

Information obtained from Enigma decryption seems to have been directed from B.S.-4 principally to the German Office of the General Staff's Section II (Intelligence). There, from fall 1935 to mid-April 1939, it was worked up by Major Jan Leśniak, who in April 1939 would turn the German Office over to another officer and himself form a Situation Office intended for wartime service. He would head the Situation Office to and through the September 1939 Campaign.^[26]

When World War II broke out on September 1, 1939, Leśniak and his colleagues had been working very intensively through the previous two or three years to establish the German order of battle and had succeeded in working out nearly 95 percent of it. The German attack on Poland did not come as a surprise to the Polish General Staff. The results obtained by Polish intelligence, according to Leśniak, had "absolutely exceeded what would normally have been possible."^[27]

Kabaty Woods

Until 1937 the Cipher Bureau's German section, BS-4, was housed in the Polish General Staff building (the stately 18th-century "Saxon Palace") in Warsaw. 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.^[28]

Gift to allies

It was there, on July 26, 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;^[29] and Commander Humphrey Sandwith, chief of the Royal Navy's intercept and direction-finding stations^[30]).

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 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.^[31]

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."^[32] After the war, Britain's Prime Minister Winston Churchill was to tell King George VI: "It was thanks to Ultra that we won the war."^[33]

Churchill's greatest fear, even after Hitler had suspended Operation Sealion and invaded the Soviet Union, was that the German submarine wolf packs would succeed in strangling sea-locked Britain.^[34] A major factor that averted Britain's defeat in the Battle of the Atlantic was her regained mastery of Naval Enigma decryption; and while the latter benefited crucially from British seizure of German Enigma-equipped naval vessels, the breaking of German naval signals ultimately relied on techniques that had been pioneered by the Polish Cipher Bureau.^[35] Had Britain capitulated to Hitler, the United States would have been deprived of an essential forward base for its subsequent involvement in the European and North African theaters.

Knox, in a letter dated August 1, 1939, thanked the Poles, in Polish, "for your cooperation and patience." He enclosed little paper batons, and a scarf picturing a Derby horse race—evidently emblematic of the cryptological race that Knox had hoped to win, using the batons, and whose personal loss he was gallantly acknowledging.^[36]

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.^[37]

Bureau abroad

Warsaw, October 1939: Hitler in his Mercedes inspects German troops before General Staff building and Thorvaldsen's statue. The military Enigma had been broken here seven years earlier.

On September 17, as the Soviet Army invaded Poland, Cipher Bureau personnel crossed the southeastern border with other Polish military and government personnel, into Romania. They eventually made their way to France where, at "PC Bruno", outside Paris, they continued breaking German Enigma traffic in collaboration with Bletchley Park, fifty miles northwest of London, England. In the interest of security, the allied cryptological services, before sending their messages over a teletype line, encrypted them using Enigma doubles. Henri Braquenié often closed messages with a "Heil Hitler!"^[38]

As late as December 1939, when Lt. Col. Gwido Langer, accompanied by Captain Braquenié, visited London and Bletchley Park, the British asked that the Polish cryptologists be turned over to them. Langer, however, took the position that the Polish team must remain where the Polish Armed Forces were being formed—on French soil.^[39] The mathematicians might actually have reached Britain much earlier—and much more comfortably—than they eventually did; but when they went to the British embassy in Bucharest, Romania, they were not recognized as important enough by preoccupied British diplomats.^[40]

PC Bruno during the Phony War. From left: Polish Lt. Col. Gwido Langer, French Major Gustave Bertrand, British Capt. Kenneth McFarlan.

Following the capitulation of France in June 1940, the Poles were evacuated to Algeria, in North Africa. On October 1, 1940, they resumed their work at "Cadix", near Uzès in unoccupied southern, Vichy France, under the sponsorship of Gustave Bertrand.^[41]

A little over two years later, on November 8, 1942, Bertrand learned from the BBC that the Allies had landed in North Africa (as part of "Operation Torch"). Knowing that the Germans planned in such an eventuality to occupy Vichy France, he evacuated Cadix on November 9. Two days later, on November 11, the Germans indeed marched into southern France. On the morning of November 12, they occupied Cadix.^[42]

Over the two years since its establishment in October 1940, Cadix had decrypted thousands of Wehrmacht, SS and Gestapo messages originating not only from French territory but from across Europe, providing invaluable intelligence to Allied commands and resistance movements.^[43]

Cadix's Polish personnel evaded the occupying Italian security police and German Gestapo, and ultimately sought to escape France via Spain.^[44] Jerzy Różycki, Jan Graliński and Piotr Smoleński had died in the January 1942 sinking of a French passenger ship in the Mediterranean.^[45] Marian Rejewski and Henryk Zygalski went to the Spanish border, where they were arrested on January 30, 1943.^[46] They were incarcerated for three months before being released, after Red Cross intervention, on May 4, 1943,^[47] and managed to join the Polish Armed Forces in Britain.^[48]

Secret preserved

Despite their travails, Rejewski and Zygalski had fared better than some of their colleagues. Cadix's Polish military chiefs, Langer and Ciężki, had also been captured — by the Germans, as they tried to cross from France into Spain on the night of March 10-11, 1943 — along with three of the other Poles: Antoni Palluth, Edward Fokczyński and Kazimierz Gaca. The first two became prisoners of war, and the other three were sent as slave labor to Germany, where Palluth and Fokczyński died.^[49] None of these men — Stefan Mayer emphasizes — despite the dire circumstances in which they were held, betrayed the secret of Enigma's decryption.^[50]

Several other Poles from Cadix, including Wiktor Michałowski, managed to reach Britain.^[51]

Before the war, Antoni Palluth (one of the lecturers in the 1929 secret Poznań University cryptology course), had been co-owner of AVA, a Warsaw radio-manufacturing enterprise that produced equipment for the Cipher Bureau. Under German occupation, some Cipher Bureau workers were interrogated by German intelligence commissions and some AVA workers were approached by German agents, but they managed to keep silent on Polish cryptologic breakthroughs and to avoid exciting suspicions about compromises to the security of the Engima systems.^[52]

In popular culture

In 1967 the Polish military historian Władysław Kozaczuk in his book Bitwa o tajemnice (Battle for Secrets) first revealed that the German Enigma had been broken by Polish cryptanalysts before World War II. The 1979 Polish film Sekret Enigmy (The Enigma Secret) [1] is a fair, if superficial, account of the Cipher Bureau's story, while the 2001 Hollywood film Enigma has been criticized for many historical inaccuracies, including omission of the crucial role of the Polish Cipher Bureau in breaking Enigma.

See also

• Polish School of Mathematics
• History of Polish Intelligence Services

Notes

References

External links

Wikimedia Commons has media related to:

Biuro Szyfrów

• "Polish Enigma Double"
• About the Enigma (National Security Agency)
• "The Enigma Code Breach" by Jan Bury
• ENIGMA
• The „Enigma” and the Intelligence
• www.enigmahistory.org
• "Codebreaking and Secret Weapons in World War II" By Bill Momsen
• A Brief History of Computing Technology, 1930 to 1939
• "THE POLES CRACK ENIGMA" (from Greg Goebel's CODES, CIPHERS, & CODEBREAKING)
• (Polish) Bolszewik złamany