Marian Rejewski
Encyclopedia
Marian Adam Rejewski ˈmarjan reˈjefski (16 August 1905 – 13 February 1980) was a Polish
mathematician
and cryptologist
who in 1932 solved the plugboard-equipped Enigma machine
, the main cipher
device used by Germany. The success of Rejewski and his colleagues Jerzy Różycki
and Henryk Zygalski
jump-started British
reading of Enigma in World War II
; the intelligence so gained, code-named "Ultra", contributed, perhaps decisively, to the defeat of Nazi Germany
.(Note 1)
While studying mathematics at Poznań University, Rejewski had attended a secret cryptology course conducted by the Polish General Staff's Biuro Szyfrów
(Cipher Bureau), which he joined full-time in 1932. The Bureau had achieved little success reading Enigma and in late 1932 set Rejewski to work on the problem. After only a few weeks, he deduced the secret internal wiring of the Enigma. Rejewski and his two mathematician colleagues then developed an assortment of techniques for the regular decryption of Enigma messages. Rejewski's contributions included devising the cryptologic "card catalog
," derived using his "cyclometer
," and the "cryptologic bomb
."
Five weeks before the German invasion of Poland
in 1939, Rejewski and his colleagues presented their results on Enigma decryption to French
and British
intelligence representatives. Shortly after the outbreak of war, the Polish cryptologists were evacuated to France
, where they continued their work in collaboration with the British and French. They were again compelled to evacuate after the fall of France in June 1940, but within months returned to work undercover in Vichy France
. After the country was fully occupied by Germany in November 1942, Rejewski and fellow mathematician Henryk Zygalski
fled, via Spain
, Portugal
and Gibraltar
, to Britain. There they worked at a Polish Army unit, solving low-level German ciphers. In 1946 Rejewski returned to his family in Poland and worked as an accountant, remaining silent about his cryptologic work until 1967.
merchant, and Matylda, née Thoms. He attended a German-speaking (Royal Grammar School in Bromberg) and completed high school with his in 1923. Rejewski then studied mathematics
at Poznań University
, graduating on 1 March 1929.
In early 1929, shortly before he graduated, Rejewski began attending a secret cryptology course organized for selected German-speaking mathematics students by the Polish General Staff's Cipher Bureau
(). The course was conducted off-campus at a military facility and, as Rejewski would discover in France in 1939 during World War II
, "was entirely and literally based" on French General Marcel Givièrge's 1925 book, Cours de cryptographie (Course of Cryptography). Rejewski and fellow students Henryk Zygalski
and Jerzy Różycki
were among the few who could keep up with the course while balancing the demands of their normal studies.
Rejewski graduated with a master's degree in mathematics on 1 March 1929; his thesis was titled, "Theory of double periodic functions of the second and third kind and its applications." A few weeks later, without having completed the cryptology course, Rejewski began the first year of a two-year actuarial statistics
course at Göttingen
, Germany. He would not complete the actuarial-statistics course, for, while home for the summer in 1930, he accepted the offer of a mathematics teaching assistantship at Poznań University.
He also began working part-time for the Biuro Szyfrów (Cipher Bureau), which by then had concluded the cryptology course and set up an outpost at Poznań to decrypt intercepted German radio
messages. Rejewski worked some twelve hours a week near the Mathematics Institute in an underground vault referred to puckishly as the "Black Chamber".
In the summer of 1932, the Poznań branch of the Cipher Bureau was disbanded. On 1 September 1932, as a civilian employee, Rejewski joined the Cipher Bureau
at the General Staff building (the Saxon Palace) in Warsaw
, as did Zygalski and Różycki.
Their first assignment was to solve a four-letter code
used by the (German Navy). Progress was initially slow, but sped up considerably after a test exchange was intercepted—a six-group signal, followed by a four-group response. The cryptologists guessed correctly that the first signal was the question, "When was Frederick the Great born?" followed by the response, "1712."
In late October or early November 1932, while work on the Naval code was still underway, Rejewski was set to work, alone and in secret, on the output of the new standard German cipher machine, the Enigma
I, which was coming into widespread use.
While the Cipher Bureau had, by later report, succeeded in solving an earlier, plugboard-less Enigma,(Note 3) it had had no success with the Enigma I.
The Enigma machine was an electromechanical device, equipped with a 26-letter keyboard and a set of 26 lamps, corresponding to the letters of the alphabet
. Inside was a set of wired drums ("rotors
" and a "reflector
") that scrambled the input. The machine also featured a plugboard
to swap pairs of letters. To encipher a letter, the operator pushed the relevant key and noted down which of the lamps lit. Each key press caused one or more rotors to advance, and thus the encipherment varied from one key press to the next.
In order for two operators to communicate, both Enigma machines had to be set up in exactly the same way. The large number of possibilities for setting the rotors and the plugboard combined to form an astronomical number of configurations, each of which would produce a different cipher. The settings were changed daily, with the consequence that the machine had to be "broken" anew each day if the messages were to be read continually.
To decrypt Enigma messages, three pieces of information were needed:
Rejewski had only the first at his disposal, based on information already acquired by the Cipher Bureau.
in cryptanalysis
. Previous methods had largely exploited linguistic pattern
s and the statistics
of natural-language
texts — letter-frequency analysis. Rejewski, however, applied techniques from group theory
— theorem
s about permutation
s — in his attack on Enigma.
These mathematical techniques, combined with material supplied by Captain Gustave Bertrand
, chief of French radio intelligence, enabled him to reconstruct the internal wirings of the machine's rotors and nonrotating reflector.
"The solution", writes historian David Kahn, "was Rejewski's own stunning achievement, one that elevates him to the pantheon of the greatest cryptanalysts of all time". Rejewski used a mathematical theorem that one mathematics professor has since described as "the theorem that won World War II".
Prior to receiving the French intelligence material, Rejewski had made a careful study of Enigma messages, particularly of the first six letters of messages intercepted on a single day.
For security, each message was encrypted using different starting positions of the rotors, as selected by the operator. This message setting was three letters long. To convey it to the receiving operator, the sending operator began the message by sending the message setting in a disguised form — a six-letter indicator.
The indicator was formed using the Enigma with its rotors set to a common global setting for that day, termed the ground setting, which was shared by all operators.
The particular way that the indicator was constructed, introduced a weakness into the cipher.
For example, suppose the operator chose the message setting KYG for a message. The operator would first set the Enigma's rotors to the ground setting, which might be GBL on that particular day, and then encrypt the message setting on the Enigma twice; that is, the operator would enter KYGKYG (which might come out to something like QZKBLX). The operator would then reposition the rotors at KYG, and encrypt the actual message. A receiving operator could reverse the process to recover first the message setting, then the message itself. The repetition of the message setting was apparently meant as an error check to detect garble
s, but it had the unforeseen effect of greatly weakening the cipher. Due to the indicator's repetition of the message setting, Rejewski knew that, in the plaintext
of the indicator, the first and fourth letters were the same, the second and fifth were the same, and the third and sixth were the same. These relations could be exploited to break into the cipher.
Rejewski studied these related pairs of letters. For example, if there were four messages that had the following indicators on the same day: BJGTDN, LIFBAB, ETULZR, TFREII, then by looking at the first and fourth letters of each set, he knew that certain pairs of letters were related. B was related to T, L was related to B, E was related to L, and T was related to E: (B,T), (L,B), (E,L), and (T,E). If he had enough different messages to work with, he could build entire sequences of relationships: the letter B was related to T, which was related to E, which was related to L, which was related to B (see diagram). This was a "cycle of 4", since it took four jumps until it got back to the start letter. Another cycle on the same day might be A
F
W
A, or a "cycle of 3". If there were enough messages on a given day, all the letters of the alphabet might be covered by a number of different cycles of various sizes. The cycles would be consistent for one day, and then would change to a different set of cycles the next day. Similar analysis could be done on the 2nd and 5th letters, and the 3rd and 6th, identifying the cycles in each case and the number of steps in each cycle.
Using the data thus gained, combined with Enigma operators' tendency to choose predictable letter combinations as indicators (such as girlfriends' initials or a pattern of keys that they saw on the Enigma keyboard), Rejewski was able to deduce six permutation
s corresponding to the encipherment at six consecutive positions of the Enigma machine. These permutations could be described by six equation
s with various unknowns, representing the wiring within the entry drum, rotors, reflector, and plugboard.
(the Deuxième Bureau
), under future General Gustave Bertrand
, had obtained and passed on to the Polish Cipher Bureau. The documents, procured from a spy
in the German Cryptographic Service, Hans-Thilo Schmidt
, included the Enigma settings for the months of September and October 1932. About December 9 or 10, (Note 4) 1932, the documents were given to Rejewski. They enabled him to reduce the number of unknowns and solve the wirings of the rotors and reflector.
There was another obstacle to overcome, however. The military Enigma had been modified from the commercial Enigma, of which Rejewski had had an actual example to study. In the commercial machine, the keys were connected to the entry drum in German keyboard order ("QWERTZU..."). However, in the military Enigma, the connections had instead been wired in alphabetical order: "ABCDEF..." This new wiring sequence foiled British cryptologists working on Enigma, who dismissed the "ABCDEF..." wiring as too obvious. Rejewski, perhaps guided by an intuition about a German fondness for order, simply guessed that the wiring was the normal alphabetic ordering. He later recalled that, after he had made this assumption, "from my pencil, as by magic, began to issue numbers designating the connections in rotor N. Thus the connections in one rotor, the right-hand rotor, were finally known."
The settings provided by French Intelligence covered two months which straddled a changeover period for the rotor ordering. A different rotor happened to be in the right-hand position for the second month, and so the wirings of two rotors could be recovered by the same method.(Note 5) Rejewski later recalled: "Finding the [wiring] in the third [rotor], and especially... in the [reflector], now presented no great difficulties. Likewise there were no difficulties with determining the correct torsion of the [rotors'] side walls with respect to each other, or the moments when the left and middle drums turned." By year's end 1932, the wirings of all three rotors and the reflector had been recovered. A sample message in an Enigma instruction manual, providing a plaintext
and its corresponding ciphertext
produced using a stated daily key and message key, helped clarify some remaining details.
There has been speculation as to whether the rotor wirings could have been solved without the documents supplied by French Intelligence. Rejewski recalled in 1980 that another way had been found that could have been used to achieve this, but that the method was "imperfect and tedious" and relied on chance. (In 2005, mathematician John Lawrence published a paper arguing that it would have taken four years for this method to have had a reasonable likelihood of success.) Rejewski wrote that "the conclusion is that the intelligence material furnished to us should be regarded as having been decisive to solution of the machine."
", based on the fact that the plugboard's connections exchanged only six pairs of letters, leaving fourteen letters unchanged.
Next was Różycki's "clock" method, which sometimes made it possible to determine which rotor was at the right-hand side of the Enigma machine on a given day.
After 1 October 1936, German procedure changed, and the number of plugboard connections became variable, ranging between five and eight. As a result, the grill method became considerably less effective.
However, a method using a card catalog
had been devised around 1934 or 1935, and was independent of the number of plug connections. The catalog was constructed using Rejewski's "cyclometer
", a special-purpose device for creating a catalog of permutations. Once the catalog was complete, the permutation could be looked up in the catalog, yielding the Enigma rotor settings for that day.
The cyclometer comprised two sets of Enigma rotors, and was used to determine the length and number of cycles of the permutations that could be generated by the Enigma machine. Even with the cyclometer, preparing the catalog was a long and difficult task. Each position of the Enigma machine (there were 17,576 positions) had to be examined for each possible sequence of rotors (there were 6 possible sequences); therefore, the catalog comprised 105,456 entries. Preparation of the catalog took over a year, but when it was ready about 1935, it made obtaining daily keys a matter of 12–20 minutes.
However, on November 1 or 2, 1937, the Germans replaced the reflector
in their Enigma machines, which meant that the entire catalog had to be recalculated from scratch.
Nonetheless, by January 1938 the Cipher Bureau's German section was reading a remarkable 75% of Enigma intercepts, and according to Rejewski, with a minimal increase in personnel this could have been increased to 90%.
in the Kabaty Woods south of Warsaw.
On 15 September 1938, the Germans put into effect new rules for enciphering message keys (a new "indicator procedure"), rendering the card-catalog method completely useless. (Note 7) The Polish cryptologists rapidly responded with new techniques.
One was Rejewski's ("bomb"), an electrically powered aggregate of six Enigmas, which made it possible to solve the daily keys in about two hours. Six bomb
s were built and ready for use by mid-November 1938. The bomb
method, like the grill method, exploited the fact that the plug connections did not change all the letters. But while the grill method required unchanged pairs of letters, the bomb method required only unchanged letters. Hence it could be applied even though the number of plug connections in this period was five to eight.
But from 1 January 1939 the number of plug connections was increased to seven-to-ten, greatly decreasing the usefulness of the bombs. Moreover, two weeks earlier, on 15 December 1938, the Germans had increased the number of rotors from three to five, thereby increasing the bombs' workload tenfold. Building an additional 54 bombs, in order to increase the number tenfold to 60 from the original 6, would have utterly exceeded the Polish Cipher Bureau's available funds.
The British bombe
, the main tool that would be used to break Enigma messages during World War II, would be named after, and likely inspired by, the Polish bomb
, though according to Gordon Welchman
the cryptanalytic methods embodied by the two machines were different.
Around the same time as the Polish bomb
, a manual method was invented by Zygalski
, that of "perforated sheets
" ("Zygalski sheets"), which, like the card-catalog method, was independent of the number of plug connections. But production of these sheets was very time-consuming, so that by 15 December 1938 only one-third of the job had been done.
The Polish methods were revealed to French
and British intelligence representatives in a meeting at Pyry
, south of Warsaw
, on 25 July 1939. France was represented by Gustave Bertrand
and Henri Braquenié
; Britain, by Alastair Denniston
, Alfred Dillwyn Knox and Royal Navy
electronics expert Humphrey Sandwith. The Polish hosts included Stefan Mayer
, Gwido Langer
, Maksymilian Ciężki
and the three cryptologists.
The Poles' gift of Enigma decryption to their Western allies, five weeks before the outbreak of World War II, came not a moment too soon. Knowledge that the cipher was crackable was a morale boost to Allied cryptologists. The British were able to manufacture at least two complete sets of perforated sheets—they sent one to PC Bruno
, outside Paris, in mid-December 1939—and began reading Enigma within months of the outbreak of war.
Without the Polish assistance, British cryptologists would, at the very least, have been considerably delayed in reading Enigma. Author Hugh Sebag-Montefiore concludes that substantial breaks into German Army and Air Force Enigma ciphers by the British would have occurred only after November 1941 at the earliest, after an Enigma machine and key lists had been captured, and similarly into Naval Enigma only after late 1942. Former Bletchley Park
cryptologist Gordon Welchman
goes further, writing that the Army and Air Force Enigma section, Hut 6
, "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."
Intelligence gained from solving high-level German ciphers—intelligence codenamed "Ultra" by the British and Americans—came chiefly from Enigma decrypts. While the exact contribution of Ultra intelligence to Allied victory is disputed, Kozaczuk and Straszak note that "it is widely believed that Ultra saved the world at least two years of war and possibly prevented Hitler from winning." The English historian Sir Harry Hinsley
, who worked at Bletchley Park, similarly assessed it as having "shortened the war by not less than two years and probably by four years". The availability of Ultra was, at the least, due largely to the earlier Polish breaking of Enigma.
In September 1939, after the outbreak of World War II, Rejewski and his fellow Cipher Bureau workers were evacuated from Poland to Romania
, crossing the border on September 17 (the day the Soviet Union
invaded eastern Poland).
Rejewski, Zygalski and Różycki managed to avoid being interned in a refugee camp and made their way to Bucharest
, where they contacted the British embassy. Having been told by the British to "come back in a few days," they next tried the French embassy, introducing themselves as "friends of Bolek" (Bertrand's Polish code name) and asking to speak with a French military officer. A French Army colonel telephoned Paris and immediately issued instructions for the three Poles to be assisted in evacuating to Paris.
On 20 October 1939 the three Polish cryptologists resumed work on German ciphers at a joint French-Polish-Spanish radio-intelligence unit stationed at Gretz-Armainvillers, forty kilometers northeast of Paris, and housed in the Château de Vignolles (code-named "PC Bruno"). On January 17, 1940, the Poles found the first Enigma key to be solved in France, one for October 28, 1939.
The staff at PC Bruno collaborated by teleprinter
with their opposite numbers at Bletchley Park
in England. For communications security, the allied Polish, French and British cryptologic agencies used the Enigma machine itself—Bruno closing its Enigma-encrypted messages to Britain with an ironic "Heil Hitler!"
On 24 June 1940, after Germany's victory in the Battle of France
, Gustave Bertrand
flew Bruno's international personnel—fifteen Poles, and seven Spaniards who worked on Italian
ciphers—in three planes to Algeria
.
During September 1940 they returned to work in secret in unoccupied southern (Vichy) France. Rejewski's cover was as Pierre Ranaud, a lycée professor from Nantes
. A radio intelligence station was set up at the Château des Fouzes near Uzès
, code-named "Cadix
". Cadix began operations on 1 October. Rejewski and his colleagues solved German telegraph
ciphers, and also the Swiss version of the Enigma machine (which had no plugboard). Rejewski may have had little or no involvement in working on German Enigma at Cadix.(Note 8)
In early July 1941, Rejewski and Zygalski were asked to try solving messages enciphered on the secret Polish Lacida
cipher machine, which was used for secure communications between Cadix
and the Polish General Staff in London. Lacida was a rotor machine
based on the same cryptographic principle as Enigma, yet had never been subjected to rigorous security analysis. The two cryptologists created consternation by breaking the first message within a couple of hours; further messages were solved in a similar way.
On 9 January 1942, Różycki
, the youngest of the three mathematicians, died in the sinking of a French passenger ship
as he was returning from a stint in Algeria to Cadix in southern France.
By summer 1942 work at Cadix
was becoming dangerous, and plans for evacuation were drawn up. Vichy France itself was liable to be occupied by German troops, and Cadix's radio transmissions were increasingly at risk of detection by the Funkabwehr, a German unit tasked with locating enemy radio transmitters. Indeed, on 6 November a pickup truck
equipped with a circular antenna
arrived at the gate of the chateau where the cryptologists were operating. The visitors, however, did not enter, and merely investigated — and terrorized — nearby farms. Nonetheless, the order to evacuate Cadix was given, and this was done by 9 November. The Germans occupied the chateau only three days later.
, which was in the Italian-occupied zone. They had to flee again after coming under suspicion, constantly moving or staying in hiding, to Cannes
, Antibes
, Nice again, Marseilles, Toulouse
, Narbonne
, Perpignan
and Ax-les-Thermes
, close to the Spanish border.
The plan was to smuggle themselves over the Pyrenees
into Spain
. On 29 January 1943, accompanied by a local guide, Rejewski and Zygalski began their trek across the Pyrenees, avoiding German and Vichy patrols. Near midnight and near the Spanish border, the guide pulled out a pistol
and demanded that they hand over the rest of their money. After being robbed they succeeded in reaching the Spanish side of the border, only to be arrested within hours by security police.
The Poles were sent first to a prison in La Seu d'Urgell
until 24 March, then moved to a prison at Lerida. The pair were eventually released on 4 May 1943, after the intervention of the Polish Red Cross
, and sent to Madrid
. Leaving Madrid on 21 July, they made it to Portugal
; from there aboard HMS Scottish to Gibraltar
; and thence aboard an old Dakota
to RAF Hendon, in north London
, arriving on 3 August 1943.
s into the Polish Army on 16 August 1943 and were posted to a Polish Army facility in Boxmoor
, cracking German SS
and SD
hand ciphers. The ciphers were usually based on the Doppelkassettenverfahren ("double Playfair
") system, which the two cryptologists had already worked on in France. On 10 October 1943, Rejewski and Zygalski were commissioned second lieutenant
s; on 1 January 1945 Rejewski, and presumably also Zygalski, were promoted to lieutenant
.
Enigma decryption, however, had become an exclusively British and American domain; the two mathematicians who, with their late colleague, had laid the foundations for Allied Enigma decryption were now excluded from making further contributions to their métier. British cryptologist Alan Stripp suggests that by that time, at Bletchley Park
, "very few even knew about the Polish contribution" because of the strict secrecy and the "need-to-know" principle. Stripp comments further that "Setting them to work on the Doppelkassetten system was like using racehorses to pull wagons."
Rejewski took a position in Bydgoszcz as director of the sales department at a cable manufacturing company, Kabel Polski (Polish Cable).
Between 1949 and 1958, Rejewski was repeatedly investigated by the Polish Security Service but never divulged that he had worked on Enigma; in 1950 they demanded that he be fired from his employment. He then worked briefly as a director at the State Surveying Company, then at the Association of Polish Surveyors. From 1951 to 1954 he worked at the Association of Timber and Varied Manufactures Cooperatives. From 1954 until his retirement on a disability pension in February 1967, he was director of the inspectorate of costs and prices at a Provincial Association of Labor Cooperatives.
In 1969 Rejewski and his family moved back to Warsaw
, to the apartment that he had acquired in May 1939 with financial help from his father-in-law. (After the Germans suppressed the 1944 Warsaw Uprising, they had sent Mrs. Rejewska and her children, along with other Warsaw survivors, west, where the family had eventually found refuge with her parents in Bydgoszcz.)
Rejewski understandably took satisfaction from his accomplishments in breaking the German Enigma cipher
for nearly seven years (beginning in December 1932) prior to the outbreak of World War II
and then into the war, in personal and teleprinter
collaboration with Bletchley Park
, at least until the 1940 fall of France. In 1942, at Uzès
, Vichy France
, he wrote a "Report of Cryptologic Work on the German Enigma Machine Cipher." Before his retirement in 1967 a quarter-century later, he began writing his "Memoirs of My Work in the Cipher Bureau of Section II of the [Polish] General Staff," which were purchased by the Military Historical Institute, located in Warsaw.
Rejewski must often have wondered, after the 1940 French debacle, what use Alan Turing
(who had visited the Polish cryptologists outside Paris
) and Bletchley Park
, had ultimately made of the Polish discoveries and inventions. For nearly three decades after the war, little was publicly known due to a ban that had been imposed on 25 May 1945 by British Prime Minister Winston Churchill
.
What little was published attracted little attention. Ladislas Farago
's 1971 best-seller The Game of the Foxes presented a garbled account of Ultra's origins: "Commander Denniston
went clandestinely to a secluded Polish castle [!] on the eve of the war [to pick up an Enigma, "the Wehrmacht's top system" during World War II]. Dilly Knox later solved its keying..." Still, this was closer to the truth than most of the British and American accounts that would follow after 1974. Their authors were at a disadvantage: they did not know that the founder of Enigma decryption, Marian Rejewski, was still alive and alert and that historical confabulation was therefore hazardous.
With Gustave Bertrand
's 1973 publication of his Enigma, substantial information about the origins of Ultra began to seep out to the broader world public. With F.W. Winterbotham's 1974 best-seller The Ultra Secret, the dam began to burst. Still, many authors likewise aspired to best-sellerdom and were not averse to filling gaps in their information with whole-cloth fabrications. Rejewski fought a gallant (if into the 21st century still not entirely successful) fight to get the truth before the public. He published a number of papers on his cryptologic work and contributed generously to articles, books and television programs. He was interviewed by scholars, journalists and television crews from Poland, East Germany, the United States, Britain, Sweden, Belgium, the Soviet Union, Yugoslavia and Brazil.
He maintained a lively correspondence with his wartime French host, General Gustave Bertrand
, and at the General's bidding began translating Bertrand's Enigma into Polish. A few years before his death, at the request of the Józef Piłsudski Institute of America, Rejewski broke enciphered correspondence of Józef Piłsudski and his fellow Polish Socialist
conspirators from 1904. On 12 August 1978, a year and a half before his death, he received the Officer's Cross of the Order of Polonia Restituta
.
Rejewski, who had been suffering from heart disease
, died of a heart attack
at his home on 13 February 1980, aged 74. He was buried with military honors at Warsaw
's Powązki Military Cemetery
.
In 2000, Rejewski and his colleagues Zygalski and Różycki were posthumously awarded the Grand Cross of the Order of Polonia Restituta
. On 4 July 2005, Rejewski's daughter Janina Sylwestrzak received on his behalf, from the British Chief of the Defence Staff, the War Medal 1939–1945
.
In 1979 Rejewski and his colleagues became heroes of Sekret Enigmy ("The Enigma Secret"), a Polish-cryptologists-and-German-spies movie thriller about the Poles' solution of the German Enigma cipher
. Late 1980 also saw a Polish TV series
with a similar theme, Tajemnice Enigmy ("The Secrets of Enigma").
In 1983, a Polish postage stamp
marked the 50th anniversary of the German military Enigma's first solution; the First Day Cover featured likenesses of the three mathematician-cryptologists. Memorials to the trio have been unveiled at Bletchley Park
and the Polish Embassy in the United Kingdom
, and at Uzès
in France. In Rejewski's home city of Bydgoszcz, a street and school have been named for him, a plaque placed on the building where he had lived, and a sculpture commissioned (pictured above). In 2005 a postcard (below) was issued, commemorating the centennial of Rejewski's birth.
In 2007, a three-sided bronze monument was dedicated before Poznań Castle
. Each side bears the name of one of the three mathematics students who had attended the 1929 cryptology course and subsequently collaborated on breaking the Enigma cipher.
Poland
Poland , officially the Republic of Poland , is a country in Central Europe bordered by Germany to the west; the Czech Republic and Slovakia to the south; Ukraine, Belarus and Lithuania to the east; and the Baltic Sea and Kaliningrad Oblast, a Russian exclave, to the north...
mathematician
Mathematician
A mathematician is a person whose primary area of study is the field of mathematics. Mathematicians are concerned with quantity, structure, space, and change....
and cryptologist
Cryptography
Cryptography is the practice and study of techniques for secure communication in the presence of third parties...
who in 1932 solved the plugboard-equipped Enigma machine
Enigma machine
An Enigma machine is any of a family of related electro-mechanical rotor cipher machines used for the encryption and decryption of secret messages. Enigma was invented by German engineer Arthur Scherbius at the end of World War I...
, the main cipher
Cipher
In cryptography, a cipher is an algorithm for performing encryption or decryption — a series of well-defined steps that can be followed as a procedure. An alternative, less common term is encipherment. In non-technical usage, a “cipher” is the same thing as a “code”; however, the concepts...
device used by Germany. The success of Rejewski and his colleagues Jerzy Różycki
Jerzy Rózycki
Jerzy Witold Różycki was a Polish mathematician and cryptologist who worked at breaking German Enigma-machine ciphers.-Life:Różycki was born in what is now Ukraine, the fourth and youngest child of Zygmunt Różycki, a pharmacist and graduate of Saint Petersburg University, and Wanda, née Benita. ...
and Henryk Zygalski
Henryk Zygalski
Henryk Zygalski was a Polish mathematician and cryptologist who worked at breaking German Enigma ciphers before and during World War II.-Life:...
jump-started British
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
reading of Enigma in World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
; the intelligence so gained, code-named "Ultra", contributed, perhaps decisively, to the defeat of Nazi Germany
End of World War II in Europe
The final battles of the European Theatre of World War II as well as the German surrender to the Western Allies and the Soviet Union took place in late April and early May 1945.-Timeline of surrenders and deaths:...
.(Note 1)
While studying mathematics at Poznań University, Rejewski had attended a secret cryptology course conducted by the Polish General Staff's Biuro Szyfrów
Biuro Szyfrów
The Biuro Szyfrów was the interwar Polish General Staff's agency charged with both cryptography and cryptology ....
(Cipher Bureau), which he joined full-time in 1932. The Bureau had achieved little success reading Enigma and in late 1932 set Rejewski to work on the problem. After only a few weeks, he deduced the secret internal wiring of the Enigma. Rejewski and his two mathematician colleagues then developed an assortment of techniques for the regular decryption of Enigma messages. Rejewski's contributions included devising the cryptologic "card catalog
Card catalog (cryptology)
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.-History:...
," derived using his "cyclometer
Cyclometer
The cyclometer was a cryptologic device designed, "probably in 1934 or 1935," by Marian Rejewski of the Polish Cipher Bureau's German section to facilitate decryption of German Enigma ciphertext.-History:...
," and the "cryptologic bomb
Bomba (cryptography)
The bomba, or bomba kryptologiczna was a special-purpose machine designed about October 1938 by Polish Cipher Bureau cryptologist Marian Rejewski to break German Enigma-machine ciphers....
."
Five weeks before the German invasion of Poland
Invasion of Poland (1939)
The Invasion of Poland, also known as the September Campaign or 1939 Defensive War in Poland and the Poland Campaign in Germany, was an invasion of Poland by Germany, the Soviet Union, and a small Slovak contingent that marked the start of World War II in Europe...
in 1939, Rejewski and his colleagues presented their results on Enigma decryption to French
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
and British
Great Britain
Great Britain or Britain is an island situated to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island, as well as the largest of the British Isles...
intelligence representatives. Shortly after the outbreak of war, the Polish cryptologists were evacuated to France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
, where they continued their work in collaboration with the British and French. They were again compelled to evacuate after the fall of France in June 1940, but within months returned to work undercover in Vichy France
Vichy France
Vichy France, Vichy Regime, or Vichy Government, are common terms used to describe the government of France that collaborated with the Axis powers from July 1940 to August 1944. This government succeeded the Third Republic and preceded the Provisional Government of the French Republic...
. After the country was fully occupied by Germany in November 1942, Rejewski and fellow mathematician Henryk Zygalski
Henryk Zygalski
Henryk Zygalski was a Polish mathematician and cryptologist who worked at breaking German Enigma ciphers before and during World War II.-Life:...
fled, via Spain
Spain
Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...
, Portugal
Portugal
Portugal , officially the Portuguese Republic is a country situated in southwestern Europe on the Iberian Peninsula. Portugal is the westernmost country of Europe, and is bordered by the Atlantic Ocean to the West and South and by Spain to the North and East. The Atlantic archipelagos of the...
and Gibraltar
Gibraltar
Gibraltar is a British overseas territory located on the southern end of the Iberian Peninsula at the entrance of the Mediterranean. A peninsula with an area of , it has a northern border with Andalusia, Spain. The Rock of Gibraltar is the major landmark of the region...
, to Britain. There they worked at a Polish Army unit, solving low-level German ciphers. In 1946 Rejewski returned to his family in Poland and worked as an accountant, remaining silent about his cryptologic work until 1967.
Education and early work
Marian Rejewski was born 16 August 1905 in Bromberg, now Bydgoszcz.(Note 2) His parents were Józef, a cigarCigar
A cigar is a tightly-rolled bundle of dried and fermented tobacco that is ignited so that its smoke may be drawn into the mouth. Cigar tobacco is grown in significant quantities in Brazil, Cameroon, Cuba, the Dominican Republic, Honduras, Indonesia, Mexico, Nicaragua, Philippines, and the Eastern...
merchant, and Matylda, née Thoms. He attended a German-speaking (Royal Grammar School in Bromberg) and completed high school with his in 1923. Rejewski then studied mathematics
Mathematics
Mathematics is the study of quantity, space, structure, and change. Mathematicians seek out patterns and formulate new conjectures. Mathematicians resolve the truth or falsity of conjectures by mathematical proofs, which are arguments sufficient to convince other mathematicians of their validity...
at Poznań University
Adam Mickiewicz University in Poznan
Adam Mickiewicz University is one of the major Polish universities, located in the city of Poznań in western Poland. It opened on May 7, 1919, and since 1955 has carried the name of the Polish poet Adam Mickiewicz.-History:...
, graduating on 1 March 1929.
In early 1929, shortly before he graduated, Rejewski began attending a secret cryptology course organized for selected German-speaking mathematics students by the Polish General Staff's Cipher Bureau
Biuro Szyfrów
The Biuro Szyfrów was the interwar Polish General Staff's agency charged with both cryptography and cryptology ....
(). The course was conducted off-campus at a military facility and, as Rejewski would discover in France in 1939 during World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
, "was entirely and literally based" on French General Marcel Givièrge's 1925 book, Cours de cryptographie (Course of Cryptography). Rejewski and fellow students Henryk Zygalski
Henryk Zygalski
Henryk Zygalski was a Polish mathematician and cryptologist who worked at breaking German Enigma ciphers before and during World War II.-Life:...
and Jerzy Różycki
Jerzy Rózycki
Jerzy Witold Różycki was a Polish mathematician and cryptologist who worked at breaking German Enigma-machine ciphers.-Life:Różycki was born in what is now Ukraine, the fourth and youngest child of Zygmunt Różycki, a pharmacist and graduate of Saint Petersburg University, and Wanda, née Benita. ...
were among the few who could keep up with the course while balancing the demands of their normal studies.
Rejewski graduated with a master's degree in mathematics on 1 March 1929; his thesis was titled, "Theory of double periodic functions of the second and third kind and its applications." A few weeks later, without having completed the cryptology course, Rejewski began the first year of a two-year actuarial statistics
Actuary
An actuary is a business professional who deals with the financial impact of risk and uncertainty. Actuaries provide expert assessments of financial security systems, with a focus on their complexity, their mathematics, and their mechanisms ....
course at Göttingen
Göttingen
Göttingen is a university town in Lower Saxony, Germany. It is the capital of the district of Göttingen. The Leine river runs through the town. In 2006 the population was 129,686.-General information:...
, Germany. He would not complete the actuarial-statistics course, for, while home for the summer in 1930, he accepted the offer of a mathematics teaching assistantship at Poznań University.
He also began working part-time for the Biuro Szyfrów (Cipher Bureau), which by then had concluded the cryptology course and set up an outpost at Poznań to decrypt intercepted German radio
Radio
Radio is the transmission of signals through free space by modulation of electromagnetic waves with frequencies below those of visible light. Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space...
messages. Rejewski worked some twelve hours a week near the Mathematics Institute in an underground vault referred to puckishly as the "Black Chamber".
In the summer of 1932, the Poznań branch of the Cipher Bureau was disbanded. On 1 September 1932, as a civilian employee, Rejewski joined the Cipher Bureau
Biuro Szyfrów
The Biuro Szyfrów was the interwar Polish General Staff's agency charged with both cryptography and cryptology ....
at the General Staff building (the Saxon Palace) in Warsaw
Warsaw
Warsaw is the capital and largest city of Poland. It is located on the Vistula River, roughly from the Baltic Sea and from the Carpathian Mountains. Its population in 2010 was estimated at 1,716,855 residents with a greater metropolitan area of 2,631,902 residents, making Warsaw the 10th most...
, as did Zygalski and Różycki.
Their first assignment was to solve a four-letter code
Code (cryptography)
In cryptography, a code is a method used to transform a message into an obscured form, preventing those who do not possess special information, or key, required to apply the transform from understanding what is actually transmitted. The usual method is to use a codebook with a list of common...
used by the (German Navy). Progress was initially slow, but sped up considerably after a test exchange was intercepted—a six-group signal, followed by a four-group response. The cryptologists guessed correctly that the first signal was the question, "When was Frederick the Great born?" followed by the response, "1712."
Enigma machine
Enigma machine
An Enigma machine is any of a family of related electro-mechanical rotor cipher machines used for the encryption and decryption of secret messages. Enigma was invented by German engineer Arthur Scherbius at the end of World War I...
I, which was coming into widespread use.
While the Cipher Bureau had, by later report, succeeded in solving an earlier, plugboard-less Enigma,(Note 3) it had had no success with the Enigma I.
The Enigma machine was an electromechanical device, equipped with a 26-letter keyboard and a set of 26 lamps, corresponding to the letters of the alphabet
Latin alphabet
The Latin alphabet, also called the Roman alphabet, is the most recognized alphabet used in the world today. It evolved from a western variety of the Greek alphabet called the Cumaean alphabet, which was adopted and modified by the Etruscans who ruled early Rome...
. Inside was a set of wired drums ("rotors
Rotor machine
In cryptography, a rotor machine is an electro-mechanical device used for encrypting and decrypting secret messages. Rotor machines were the cryptographic state-of-the-art for a prominent period of history; they were in widespread use in the 1920s–1970s...
" and a "reflector
Reflector (cipher machine)
A reflector, in cryptology, is a component of some rotor cipher machines, such as the Enigma machine, that sends electrical impulses that have reached it from the machine's rotors, back in reverse order through those rotors.- Other names :...
") that scrambled the input. The machine also featured a plugboard
Plugboard
A plugboard, or control panel , is an array of jacks, or hubs, into which patch cords can be inserted to complete an electrical circuit. Control panels were used to direct the operation of some unit record equipment...
to swap pairs of letters. To encipher a letter, the operator pushed the relevant key and noted down which of the lamps lit. Each key press caused one or more rotors to advance, and thus the encipherment varied from one key press to the next.
In order for two operators to communicate, both Enigma machines had to be set up in exactly the same way. The large number of possibilities for setting the rotors and the plugboard combined to form an astronomical number of configurations, each of which would produce a different cipher. The settings were changed daily, with the consequence that the machine had to be "broken" anew each day if the messages were to be read continually.
To decrypt Enigma messages, three pieces of information were needed:
- A general understanding of how Enigma functioned
- The wiring of the rotors
- The daily settings: the sequence and orientations of the rotors (of which there were three initially), and the plug connections on the plugboard
Rejewski had only the first at his disposal, based on information already acquired by the Cipher Bureau.
Solving Enigma's wiring
First Rejewski tackled the problem of finding the wiring of the rotors. To do this, he pioneered the use of pure mathematicsPure mathematics
Broadly speaking, pure mathematics is mathematics which studies entirely abstract concepts. From the eighteenth century onwards, this was a recognized category of mathematical activity, sometimes characterized as speculative mathematics, and at variance with the trend towards meeting the needs of...
in cryptanalysis
Cryptanalysis
Cryptanalysis is the study of methods for obtaining the meaning of encrypted information, without access to the secret information that is normally required to do so. Typically, this involves knowing how the system works and finding a secret key...
. Previous methods had largely exploited linguistic pattern
Linguistics
Linguistics is the scientific study of human language. Linguistics can be broadly broken into three categories or subfields of study: language form, language meaning, and language in context....
s and the statistics
Statistics
Statistics is the study of the collection, organization, analysis, and interpretation of data. It deals with all aspects of this, including the planning of data collection in terms of the design of surveys and experiments....
of natural-language
Natural language
In the philosophy of language, a natural language is any language which arises in an unpremeditated fashion as the result of the innate facility for language possessed by the human intellect. A natural language is typically used for communication, and may be spoken, signed, or written...
texts — letter-frequency analysis. Rejewski, however, applied techniques from group theory
Group theory
In mathematics and abstract algebra, group theory studies the algebraic structures known as groups.The concept of a group is central to abstract algebra: other well-known algebraic structures, such as rings, fields, and vector spaces can all be seen as groups endowed with additional operations and...
— theorem
Theorem
In mathematics, a theorem is a statement that has been proven on the basis of previously established statements, such as other theorems, and previously accepted statements, such as axioms...
s about permutation
Permutation
In mathematics, the notion of permutation is used with several slightly different meanings, all related to the act of permuting objects or values. Informally, a permutation of a set of objects is an arrangement of those objects into a particular order...
s — in his attack on Enigma.
These mathematical techniques, combined with material supplied by Captain Gustave Bertrand
Gustave Bertrand
Gustave Bertrand 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...
, chief of French radio intelligence, enabled him to reconstruct the internal wirings of the machine's rotors and nonrotating reflector.
"The solution", writes historian David Kahn, "was Rejewski's own stunning achievement, one that elevates him to the pantheon of the greatest cryptanalysts of all time". Rejewski used a mathematical theorem that one mathematics professor has since described as "the theorem that won World War II".
Prior to receiving the French intelligence material, Rejewski had made a careful study of Enigma messages, particularly of the first six letters of messages intercepted on a single day.
For security, each message was encrypted using different starting positions of the rotors, as selected by the operator. This message setting was three letters long. To convey it to the receiving operator, the sending operator began the message by sending the message setting in a disguised form — a six-letter indicator.
The indicator was formed using the Enigma with its rotors set to a common global setting for that day, termed the ground setting, which was shared by all operators.
The particular way that the indicator was constructed, introduced a weakness into the cipher.
For example, suppose the operator chose the message setting KYG for a message. The operator would first set the Enigma's rotors to the ground setting, which might be GBL on that particular day, and then encrypt the message setting on the Enigma twice; that is, the operator would enter KYGKYG (which might come out to something like QZKBLX). The operator would then reposition the rotors at KYG, and encrypt the actual message. A receiving operator could reverse the process to recover first the message setting, then the message itself. The repetition of the message setting was apparently meant as an error check to detect garble
Garble
Garble is a blogging system based on the Jasper web programming framework. It also supports Facebook integration via the About Face theme.- External links :* * for the word garble, see wikt:garble...
s, but it had the unforeseen effect of greatly weakening the cipher. Due to the indicator's repetition of the message setting, Rejewski knew that, in the plaintext
Plaintext
In cryptography, plaintext is information a sender wishes to transmit to a receiver. Cleartext is often used as a synonym. Before the computer era, plaintext most commonly meant message text in the language of the communicating parties....
of the indicator, the first and fourth letters were the same, the second and fifth were the same, and the third and sixth were the same. These relations could be exploited to break into the cipher.
Rejewski studied these related pairs of letters. For example, if there were four messages that had the following indicators on the same day: BJGTDN, LIFBAB, ETULZR, TFREII, then by looking at the first and fourth letters of each set, he knew that certain pairs of letters were related. B was related to T, L was related to B, E was related to L, and T was related to E: (B,T), (L,B), (E,L), and (T,E). If he had enough different messages to work with, he could build entire sequences of relationships: the letter B was related to T, which was related to E, which was related to L, which was related to B (see diagram). This was a "cycle of 4", since it took four jumps until it got back to the start letter. Another cycle on the same day might be A
FWA, or a "cycle of 3". If there were enough messages on a given day, all the letters of the alphabet might be covered by a number of different cycles of various sizes. The cycles would be consistent for one day, and then would change to a different set of cycles the next day. Similar analysis could be done on the 2nd and 5th letters, and the 3rd and 6th, identifying the cycles in each case and the number of steps in each cycle.Using the data thus gained, combined with Enigma operators' tendency to choose predictable letter combinations as indicators (such as girlfriends' initials or a pattern of keys that they saw on the Enigma keyboard), Rejewski was able to deduce six permutation
Permutation
In mathematics, the notion of permutation is used with several slightly different meanings, all related to the act of permuting objects or values. Informally, a permutation of a set of objects is an arrangement of those objects into a particular order...
s corresponding to the encipherment at six consecutive positions of the Enigma machine. These permutations could be described by six equation
Equation
An equation is a mathematical statement that asserts the equality of two expressions. In modern notation, this is written by placing the expressions on either side of an equals sign , for examplex + 3 = 5\,asserts that x+3 is equal to 5...
s with various unknowns, representing the wiring within the entry drum, rotors, reflector, and plugboard.
Help from France
At this point, Rejewski ran into difficulties due to the large number of unknowns in the set of equations that he had developed. He would later comment in 1980 that it was still not known whether such a set of six equations was soluble without further data. But he was assisted by cryptographic documents that Section D of French military intelligenceMilitary intelligence
Military intelligence is a military discipline that exploits a number of information collection and analysis approaches to provide guidance and direction to commanders in support of their decisions....
(the Deuxième Bureau
Deuxième Bureau
The Deuxième Bureau de l'État-major général was France's external military intelligence agency from 1871 to 1940. It was dissolved together with the Third Republic upon the armistice with Germany...
), under future General Gustave Bertrand
Gustave Bertrand
Gustave Bertrand 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...
, had obtained and passed on to the Polish Cipher Bureau. The documents, procured from a spy
SPY
SPY is a three-letter acronym that may refer to:* SPY , ticker symbol for Standard & Poor's Depositary Receipts* SPY , a satirical monthly, trademarked all-caps* SPY , airport code for San Pédro, Côte d'Ivoire...
in the German Cryptographic Service, Hans-Thilo Schmidt
Hans-Thilo Schmidt
Hans-Thilo Schmidt codenamed Asché or Source D, was a spy who, during the 1930s, sold secrets about the Germans' Enigma machine to the French...
, included the Enigma settings for the months of September and October 1932. About December 9 or 10, (Note 4) 1932, the documents were given to Rejewski. They enabled him to reduce the number of unknowns and solve the wirings of the rotors and reflector.
There was another obstacle to overcome, however. The military Enigma had been modified from the commercial Enigma, of which Rejewski had had an actual example to study. In the commercial machine, the keys were connected to the entry drum in German keyboard order ("QWERTZU..."). However, in the military Enigma, the connections had instead been wired in alphabetical order: "ABCDEF..." This new wiring sequence foiled British cryptologists working on Enigma, who dismissed the "ABCDEF..." wiring as too obvious. Rejewski, perhaps guided by an intuition about a German fondness for order, simply guessed that the wiring was the normal alphabetic ordering. He later recalled that, after he had made this assumption, "from my pencil, as by magic, began to issue numbers designating the connections in rotor N. Thus the connections in one rotor, the right-hand rotor, were finally known."
The settings provided by French Intelligence covered two months which straddled a changeover period for the rotor ordering. A different rotor happened to be in the right-hand position for the second month, and so the wirings of two rotors could be recovered by the same method.(Note 5) Rejewski later recalled: "Finding the [wiring] in the third [rotor], and especially... in the [reflector], now presented no great difficulties. Likewise there were no difficulties with determining the correct torsion of the [rotors'] side walls with respect to each other, or the moments when the left and middle drums turned." By year's end 1932, the wirings of all three rotors and the reflector had been recovered. A sample message in an Enigma instruction manual, providing a plaintext
Plaintext
In cryptography, plaintext is information a sender wishes to transmit to a receiver. Cleartext is often used as a synonym. Before the computer era, plaintext most commonly meant message text in the language of the communicating parties....
and its corresponding ciphertext
Ciphertext
In cryptography, ciphertext is the result of encryption performed on plaintext using an algorithm, called a cipher. Ciphertext is also known as encrypted or encoded information because it contains a form of the original plaintext that is unreadable by a human or computer without the proper cipher...
produced using a stated daily key and message key, helped clarify some remaining details.
There has been speculation as to whether the rotor wirings could have been solved without the documents supplied by French Intelligence. Rejewski recalled in 1980 that another way had been found that could have been used to achieve this, but that the method was "imperfect and tedious" and relied on chance. (In 2005, mathematician John Lawrence published a paper arguing that it would have taken four years for this method to have had a reasonable likelihood of success.) Rejewski wrote that "the conclusion is that the intelligence material furnished to us should be regarded as having been decisive to solution of the machine."
Solving daily settings
After Rejewski had determined the wiring in the remaining rotors, he was joined in early 1933 by Różycki and Zygalski in devising methods and equipment to break Enigma ciphers routinely.(Note 6) Rejewski later recalled:Now we had the machine, but we didn't have the keyKey (cryptography)In cryptography, a key is a piece of information that determines the functional output of a cryptographic algorithm or cipher. Without a key, the algorithm would produce no useful result. In encryption, a key specifies the particular transformation of plaintext into ciphertext, or vice versa...
s and we couldn't very well require Bertrand to keep on supplying us with the keys every month ... The situation had reversed itself: before, we'd had the keys but we hadn't had the machine — we solved the machine; now we had the machine but we didn't have the keys. We had to work out methods to find the daily keys.
Early methods
A number of methods and devices had to be invented in response to continual improvements in German operating procedure and to the Enigma machine itself. The earliest method for reconstructing daily keys was the "grillGrill (cryptology)
The grill , in cryptology, was a method used chiefly early on, before the advent of the cyclometer, by the mathematician-cryptologists of the Polish Cipher Bureau in decrypting German Enigma-machine ciphers.-Method:...
", based on the fact that the plugboard's connections exchanged only six pairs of letters, leaving fourteen letters unchanged.
Next was Różycki's "clock" method, which sometimes made it possible to determine which rotor was at the right-hand side of the Enigma machine on a given day.
After 1 October 1936, German procedure changed, and the number of plugboard connections became variable, ranging between five and eight. As a result, the grill method became considerably less effective.
However, a method using a card catalog
Card catalog (cryptology)
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.-History:...
had been devised around 1934 or 1935, and was independent of the number of plug connections. The catalog was constructed using Rejewski's "cyclometer
Cyclometer
The cyclometer was a cryptologic device designed, "probably in 1934 or 1935," by Marian Rejewski of the Polish Cipher Bureau's German section to facilitate decryption of German Enigma ciphertext.-History:...
", a special-purpose device for creating a catalog of permutations. Once the catalog was complete, the permutation could be looked up in the catalog, yielding the Enigma rotor settings for that day.
The cyclometer comprised two sets of Enigma rotors, and was used to determine the length and number of cycles of the permutations that could be generated by the Enigma machine. Even with the cyclometer, preparing the catalog was a long and difficult task. Each position of the Enigma machine (there were 17,576 positions) had to be examined for each possible sequence of rotors (there were 6 possible sequences); therefore, the catalog comprised 105,456 entries. Preparation of the catalog took over a year, but when it was ready about 1935, it made obtaining daily keys a matter of 12–20 minutes.
However, on November 1 or 2, 1937, the Germans replaced the reflector
Reflector (cipher machine)
A reflector, in cryptology, is a component of some rotor cipher machines, such as the Enigma machine, that sends electrical impulses that have reached it from the machine's rotors, back in reverse order through those rotors.- Other names :...
in their Enigma machines, which meant that the entire catalog had to be recalculated from scratch.
Nonetheless, by January 1938 the Cipher Bureau's German section was reading a remarkable 75% of Enigma intercepts, and according to Rejewski, with a minimal increase in personnel this could have been increased to 90%.
"Bomb" and sheets
In 1937 Rejewski, along with the German section of the Cipher Bureau, transferred to a secret facility near PyryPyry
Pyry is one of the southernmost neighborhoods of the city of Warsaw. Administratively part of the Ursynów district, it was originally a separate village located along ulica Puławska , which links downtown Warsaw with the town of Piaseczno...
in the Kabaty Woods south of Warsaw.
On 15 September 1938, the Germans put into effect new rules for enciphering message keys (a new "indicator procedure"), rendering the card-catalog method completely useless. (Note 7) The Polish cryptologists rapidly responded with new techniques.
One was Rejewski's ("bomb"), an electrically powered aggregate of six Enigmas, which made it possible to solve the daily keys in about two hours. Six bomb
Bomba (cryptography)
The bomba, or bomba kryptologiczna was a special-purpose machine designed about October 1938 by Polish Cipher Bureau cryptologist Marian Rejewski to break German Enigma-machine ciphers....
s were built and ready for use by mid-November 1938. The bomb
Bomba (cryptography)
The bomba, or bomba kryptologiczna was a special-purpose machine designed about October 1938 by Polish Cipher Bureau cryptologist Marian Rejewski to break German Enigma-machine ciphers....
method, like the grill method, exploited the fact that the plug connections did not change all the letters. But while the grill method required unchanged pairs of letters, the bomb method required only unchanged letters. Hence it could be applied even though the number of plug connections in this period was five to eight.
But from 1 January 1939 the number of plug connections was increased to seven-to-ten, greatly decreasing the usefulness of the bombs. Moreover, two weeks earlier, on 15 December 1938, the Germans had increased the number of rotors from three to five, thereby increasing the bombs' workload tenfold. Building an additional 54 bombs, in order to increase the number tenfold to 60 from the original 6, would have utterly exceeded the Polish Cipher Bureau's available funds.
The British bombe
Bombe
The bombe was an electromechanical device used by British cryptologists to help decipher German Enigma-machine-encrypted signals during World War II...
, the main tool that would be used to break Enigma messages during World War II, would be named after, and likely inspired by, the Polish bomb
Bomba (cryptography)
The bomba, or bomba kryptologiczna was a special-purpose machine designed about October 1938 by Polish Cipher Bureau cryptologist Marian Rejewski to break German Enigma-machine ciphers....
, though according to Gordon Welchman
Gordon Welchman
Gordon Welchman was a British-American mathematician, university professor, World War II codebreaker at Bletchley Park, and author.-Education and early career:...
the cryptanalytic methods embodied by the two machines were different.
Around the same time as the Polish bomb
Bomba (cryptography)
The bomba, or bomba kryptologiczna was a special-purpose machine designed about October 1938 by Polish Cipher Bureau cryptologist Marian Rejewski to break German Enigma-machine ciphers....
, a manual method was invented by Zygalski
Henryk Zygalski
Henryk Zygalski was a Polish mathematician and cryptologist who worked at breaking German Enigma ciphers before and during World War II.-Life:...
, that of "perforated sheets
Perforated sheets
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....
" ("Zygalski sheets"), which, like the card-catalog method, was independent of the number of plug connections. But production of these sheets was very time-consuming, so that by 15 December 1938 only one-third of the job had been done.
Allies informed
As it became clear that war was imminent and that Polish resources were insufficient to keep pace with the evolution of Enigma encryption (e.g., due to the prohibitive expense of an additional 54 bombs and due to the Poles' difficulty in producing in time the required 60 series of 26 "Zygalski sheets" each), the Polish General Staff and government decided to let their Western allies in on the secret.The Polish methods were revealed to French
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
and British intelligence representatives in a meeting at Pyry
Pyry
Pyry is one of the southernmost neighborhoods of the city of Warsaw. Administratively part of the Ursynów district, it was originally a separate village located along ulica Puławska , which links downtown Warsaw with the town of Piaseczno...
, south of Warsaw
Warsaw
Warsaw is the capital and largest city of Poland. It is located on the Vistula River, roughly from the Baltic Sea and from the Carpathian Mountains. Its population in 2010 was estimated at 1,716,855 residents with a greater metropolitan area of 2,631,902 residents, making Warsaw the 10th most...
, on 25 July 1939. France was represented by Gustave Bertrand
Gustave Bertrand
Gustave Bertrand 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...
and Henri Braquenié
Henri Braquenié
Henri Braquenié was an interbellum and World War II French Air Force officer and cryptanalyst.Captain Braquenié attended, with French Major Gustave Bertrand and another French Army officer, the January 9-10, 1939, Paris meeting of French, Polish and British military intelligence officers convened...
; Britain, by Alastair Denniston
Alastair Denniston
Commander Alexander Guthrie Denniston CMG CBE RNVR was a British codebreaker in Room 40 and first head of the Government Code and Cypher School and field hockey player...
, Alfred Dillwyn Knox and Royal Navy
Royal Navy
The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...
electronics expert Humphrey Sandwith. The Polish hosts included Stefan Mayer
Stefan Mayer
Colonel Stefan A. Mayer was a Polish military intelligence officer and prewar chief of the Intelligence Department within the Polish General Staff's Section II...
, Gwido Langer
Gwido Langer
Lt. Col. Karol Gwido Langer was chief of the Polish General Staff's Cipher Bureau from at least mid-1931.-Life:...
, Maksymilian Ciężki
Maksymilian Ciezki
Maksymilian Ciężki was the head of the German section of the Polish Cipher Bureau in the 1930s, during which time the Bureau decrypted German Enigma messages....
and the three cryptologists.
The Poles' gift of Enigma decryption to their Western allies, five weeks before the outbreak of World War II, came not a moment too soon. Knowledge that the cipher was crackable was a morale boost to Allied cryptologists. The British were able to manufacture at least two complete sets of perforated sheets—they sent one to PC Bruno
PC Bruno
PC Bruno was a Polish-French intelligence station that operated outside Paris during World War II, from October 1939 until June 9, 1940. It decrypted German ciphers, most notably messages enciphered on the Enigma machine.-History:...
, outside Paris, in mid-December 1939—and began reading Enigma within months of the outbreak of war.
Without the Polish assistance, British cryptologists would, at the very least, have been considerably delayed in reading Enigma. Author Hugh Sebag-Montefiore concludes that substantial breaks into German Army and Air Force Enigma ciphers by the British would have occurred only after November 1941 at the earliest, after an Enigma machine and key lists had been captured, and similarly into Naval Enigma only after late 1942. Former Bletchley Park
Bletchley Park
Bletchley Park is an estate located in the town of Bletchley, in Buckinghamshire, England, which currently houses the National Museum of Computing...
cryptologist Gordon Welchman
Gordon Welchman
Gordon Welchman was a British-American mathematician, university professor, World War II codebreaker at Bletchley Park, and author.-Education and early career:...
goes further, writing that the Army and Air Force Enigma section, Hut 6
Hut 6
Hut 6 was a wartime section of Bletchley Park tasked with the solution of German Army and Air Force Enigma machine ciphers. Hut 8, by contrast, attacked Naval Enigma...
, "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."
Intelligence gained from solving high-level German ciphers—intelligence codenamed "Ultra" by the British and Americans—came chiefly from Enigma decrypts. While the exact contribution of Ultra intelligence to Allied victory is disputed, Kozaczuk and Straszak note that "it is widely believed that Ultra saved the world at least two years of war and possibly prevented Hitler from winning." The English historian Sir Harry Hinsley
Harry Hinsley
Sir Francis Harry Hinsley OBE was an English historian and cryptanalyst. He worked at Bletchley Park during the Second World War and wrote widely on the history of international relations and British Intelligence during the Second World War...
, who worked at Bletchley Park, similarly assessed it as having "shortened the war by not less than two years and probably by four years". The availability of Ultra was, at the least, due largely to the earlier Polish breaking of Enigma.
PC Bruno
Romania
Romania is a country located at the crossroads of Central and Southeastern Europe, on the Lower Danube, within and outside the Carpathian arch, bordering on the Black Sea...
, crossing the border on September 17 (the day the Soviet Union
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....
invaded eastern Poland).
Rejewski, Zygalski and Różycki managed to avoid being interned in a refugee camp and made their way to Bucharest
Bucharest
Bucharest is the capital municipality, cultural, industrial, and financial centre of Romania. It is the largest city in Romania, located in the southeast of the country, at , and lies on the banks of the Dâmbovița River....
, where they contacted the British embassy. Having been told by the British to "come back in a few days," they next tried the French embassy, introducing themselves as "friends of Bolek" (Bertrand's Polish code name) and asking to speak with a French military officer. A French Army colonel telephoned Paris and immediately issued instructions for the three Poles to be assisted in evacuating to Paris.
On 20 October 1939 the three Polish cryptologists resumed work on German ciphers at a joint French-Polish-Spanish radio-intelligence unit stationed at Gretz-Armainvillers, forty kilometers northeast of Paris, and housed in the Château de Vignolles (code-named "PC Bruno"). On January 17, 1940, the Poles found the first Enigma key to be solved in France, one for October 28, 1939.
The staff at PC Bruno collaborated by teleprinter
Teleprinter
A teleprinter is a electromechanical typewriter that can be used to communicate typed messages from point to point and point to multipoint over a variety of communication channels that range from a simple electrical connection, such as a pair of wires, to the use of radio and microwave as the...
with their opposite numbers at Bletchley Park
Bletchley Park
Bletchley Park is an estate located in the town of Bletchley, in Buckinghamshire, England, which currently houses the National Museum of Computing...
in England. For communications security, the allied Polish, French and British cryptologic agencies used the Enigma machine itself—Bruno closing its Enigma-encrypted messages to Britain with an ironic "Heil Hitler!"
On 24 June 1940, after Germany's victory in the Battle of France
Battle of France
In the Second World War, the Battle of France was the German invasion of France and the Low Countries, beginning on 10 May 1940, which ended the Phoney War. The battle consisted of two main operations. In the first, Fall Gelb , German armoured units pushed through the Ardennes, to cut off and...
, Gustave Bertrand
Gustave Bertrand
Gustave Bertrand 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...
flew Bruno's international personnel—fifteen Poles, and seven Spaniards who worked on Italian
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...
ciphers—in three planes to Algeria
Algeria
Algeria , officially the People's Democratic Republic of Algeria , also formally referred to as the Democratic and Popular Republic of Algeria, is a country in the Maghreb region of Northwest Africa with Algiers as its capital.In terms of land area, it is the largest country in Africa and the Arab...
.
Cadix
Nantes
Nantes is a city in western France, located on the Loire River, from the Atlantic coast. The city is the 6th largest in France, while its metropolitan area ranks 8th with over 800,000 inhabitants....
. A radio intelligence station was set up at the Château des Fouzes near Uzès
Uzès
Uzès is a commune in the Gard department in southern France.It lies about 25 km north-northeast of Nîmes.-History:Originally Ucetia, Uzès was a small Gallo-Roman oppidum, or administrative settlement. The town lies at the source of the Eure, from where a Roman aqueduct was built in the first...
, code-named "Cadix
Cadix
Cadix was the codename of a World War II clandestine Polish-French intelligence center that operated at Uzès, on the Mediterranean coast in southern, Vichy France, for over two years from September 1940 to November 9, 1942.-History:...
". Cadix began operations on 1 October. Rejewski and his colleagues solved German telegraph
Telegraphy
Telegraphy is the long-distance transmission of messages via some form of signalling technology. Telegraphy requires messages to be converted to a code which is known to both sender and receiver...
ciphers, and also the Swiss version of the Enigma machine (which had no plugboard). Rejewski may have had little or no involvement in working on German Enigma at Cadix.(Note 8)
Lacida
The Lacida 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.-History:...
cipher machine, which was used for secure communications between Cadix
Cadix
Cadix was the codename of a World War II clandestine Polish-French intelligence center that operated at Uzès, on the Mediterranean coast in southern, Vichy France, for over two years from September 1940 to November 9, 1942.-History:...
and the Polish General Staff in London. Lacida was a rotor machine
Rotor machine
In cryptography, a rotor machine is an electro-mechanical device used for encrypting and decrypting secret messages. Rotor machines were the cryptographic state-of-the-art for a prominent period of history; they were in widespread use in the 1920s–1970s...
based on the same cryptographic principle as Enigma, yet had never been subjected to rigorous security analysis. The two cryptologists created consternation by breaking the first message within a couple of hours; further messages were solved in a similar way.
On 9 January 1942, Różycki
Jerzy Rózycki
Jerzy Witold Różycki was a Polish mathematician and cryptologist who worked at breaking German Enigma-machine ciphers.-Life:Różycki was born in what is now Ukraine, the fourth and youngest child of Zygmunt Różycki, a pharmacist and graduate of Saint Petersburg University, and Wanda, née Benita. ...
, the youngest of the three mathematicians, died in the sinking of a French passenger ship
Passenger ship
A passenger ship is a ship whose primary function is to carry passengers. The category does not include cargo vessels which have accommodations for limited numbers of passengers, such as the ubiquitous twelve-passenger freighters once common on the seas in which the transport of passengers is...
as he was returning from a stint in Algeria to Cadix in southern France.
By summer 1942 work at Cadix
Cadix
Cadix was the codename of a World War II clandestine Polish-French intelligence center that operated at Uzès, on the Mediterranean coast in southern, Vichy France, for over two years from September 1940 to November 9, 1942.-History:...
was becoming dangerous, and plans for evacuation were drawn up. Vichy France itself was liable to be occupied by German troops, and Cadix's radio transmissions were increasingly at risk of detection by the Funkabwehr, a German unit tasked with locating enemy radio transmitters. Indeed, on 6 November a pickup truck
Pickup truck
A pickup truck is a light motor vehicle with an open-top rear cargo area .-Definition:...
equipped with a circular antenna
Antenna (radio)
An antenna is an electrical device which converts electric currents into radio waves, and vice versa. It is usually used with a radio transmitter or radio receiver...
arrived at the gate of the chateau where the cryptologists were operating. The visitors, however, did not enter, and merely investigated — and terrorized — nearby farms. Nonetheless, the order to evacuate Cadix was given, and this was done by 9 November. The Germans occupied the chateau only three days later.
Escaping France
The Poles were split into twos and threes. On 11 November Rejewski and Zygalski were sent to NiceNice
Nice is the fifth most populous city in France, after Paris, Marseille, Lyon and Toulouse, with a population of 348,721 within its administrative limits on a land area of . The urban area of Nice extends beyond the administrative city limits with a population of more than 955,000 on an area of...
, which was in the Italian-occupied zone. They had to flee again after coming under suspicion, constantly moving or staying in hiding, to Cannes
Cannes
Cannes is one of the best-known cities of the French Riviera, a busy tourist destination and host of the annual Cannes Film Festival. It is a Commune of France in the Alpes-Maritimes department....
, Antibes
Antibes
Antibes is a resort town in the Alpes-Maritimes department in southeastern France.It lies on the Mediterranean in the Côte d'Azur, located between Cannes and Nice. The town of Juan-les-Pins is within the commune of Antibes...
, Nice again, Marseilles, Toulouse
Toulouse
Toulouse is a city in the Haute-Garonne department in southwestern FranceIt lies on the banks of the River Garonne, 590 km away from Paris and half-way between the Atlantic Ocean and the Mediterranean Sea...
, Narbonne
Narbonne
Narbonne is a commune in southern France in the Languedoc-Roussillon region. It lies from Paris in the Aude department, of which it is a sub-prefecture. Once a prosperous port, it is now located about from the shores of the Mediterranean Sea...
, Perpignan
Perpignan
-Sport:Perpignan is a rugby stronghold: their rugby union side, USA Perpignan, is a regular competitor in the Heineken Cup and seven times champion of the Top 14 , while their rugby league side plays in the engage Super League under the name Catalans Dragons.-Culture:Since 2004, every year in the...
and Ax-les-Thermes
Ax-les-Thermes
Ax-les-Thermes is a commune in the Ariège department in the Midi-Pyrénées region in southwestern France.It lies at the confluence of the Ariège River with three tributaries, 26 miles SSE of Foix by rail...
, close to the Spanish border.
The plan was to smuggle themselves over the Pyrenees
Pyrenees
The Pyrenees is a range of mountains in southwest Europe that forms a natural border between France and Spain...
into Spain
Spain
Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...
. On 29 January 1943, accompanied by a local guide, Rejewski and Zygalski began their trek across the Pyrenees, avoiding German and Vichy patrols. Near midnight and near the Spanish border, the guide pulled out a pistol
Pistol
When distinguished as a subset of handguns, a pistol is a handgun with a chamber that is integral with the barrel, as opposed to a revolver, wherein the chamber is separate from the barrel as a revolving cylinder. Typically, pistols have an effective range of about 100 feet.-History:The pistol...
and demanded that they hand over the rest of their money. After being robbed they succeeded in reaching the Spanish side of the border, only to be arrested within hours by security police.
The Poles were sent first to a prison in La Seu d'Urgell
La Seu d'Urgell
La Seu d'Urgell is a town located in the Catalan Pyrenees in Spain. La Seu d'Urgell is also the capital of the comarca Alt Urgell, head of the judicial district of la Seu d'Urgell and the seat of Bishop of Urgell, one of the Andorra co-princes...
until 24 March, then moved to a prison at Lerida. The pair were eventually released on 4 May 1943, after the intervention of the Polish Red Cross
Polish Red Cross
Polish Red Cross is the Polish member of International Red Cross and Red Crescent Movement. It was founded in 1919 by Dr. Benjamin Reschovsky of Warsaw City Hospital and recognized by the Red Cross on July 24th 1919, and its first president was Paweł Sapieha....
, and sent to Madrid
Madrid
Madrid is the capital and largest city of Spain. The population of the city is roughly 3.3 million and the entire population of the Madrid metropolitan area is calculated to be 6.271 million. It is the third largest city in the European Union, after London and Berlin, and its metropolitan...
. Leaving Madrid on 21 July, they made it to Portugal
Portugal
Portugal , officially the Portuguese Republic is a country situated in southwestern Europe on the Iberian Peninsula. Portugal is the westernmost country of Europe, and is bordered by the Atlantic Ocean to the West and South and by Spain to the North and East. The Atlantic archipelagos of the...
; from there aboard HMS Scottish to Gibraltar
Gibraltar
Gibraltar is a British overseas territory located on the southern end of the Iberian Peninsula at the entrance of the Mediterranean. A peninsula with an area of , it has a northern border with Andalusia, Spain. The Rock of Gibraltar is the major landmark of the region...
; and thence aboard an old Dakota
Douglas DC-3
The Douglas DC-3 is an American fixed-wing propeller-driven aircraft whose speed and range revolutionized air transport in the 1930s and 1940s. Its lasting impact on the airline industry and World War II makes it one of the most significant transport aircraft ever made...
to RAF Hendon, in north London
London
London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...
, arriving on 3 August 1943.
Britain
Rejewski and Zygalski were inducted as privatePrivate (rank)
A Private is a soldier of the lowest military rank .In modern military parlance, 'Private' is shortened to 'Pte' in the United Kingdom and other Commonwealth countries and to 'Pvt.' in the United States.Notably both Sir Fitzroy MacLean and Enoch Powell are examples of, rare, rapid career...
s into the Polish Army on 16 August 1943 and were posted to a Polish Army facility in Boxmoor
Boxmoor
Boxmoor, or Boxmoor Village, is a district of Dacorum in Hertfordshire, England. It is now part of Hemel Hempstead. It is a district of mainly nineteenth century housing and meadowland, repeatedly cut through by transport links from London to the The Midlands....
, cracking German SS
Schutzstaffel
The Schutzstaffel |Sig runes]]) was a major paramilitary organization under Adolf Hitler and the Nazi Party. Built upon the Nazi ideology, the SS under Heinrich Himmler's command was responsible for many of the crimes against humanity during World War II...
and SD
Sicherheitsdienst
Sicherheitsdienst , full title Sicherheitsdienst des Reichsführers-SS, or SD, was the intelligence agency of the SS and the Nazi Party in Nazi Germany. The organization was the first Nazi Party intelligence organization to be established and was often considered a "sister organization" with the...
hand ciphers. The ciphers were usually based on the Doppelkassettenverfahren ("double Playfair
Playfair cipher
The Playfair cipher or Playfair square is a manual symmetric encryption technique and was the first literal digraph substitution cipher. The scheme was invented in 1854 by Charles Wheatstone, but bears the name of Lord Playfair who promoted the use of the cipher.The technique encrypts pairs of...
") system, which the two cryptologists had already worked on in France. On 10 October 1943, Rejewski and Zygalski were commissioned second lieutenant
Second Lieutenant
Second lieutenant is a junior commissioned officer military rank in many armed forces.- United Kingdom and Commonwealth :The rank second lieutenant was introduced throughout the British Army in 1871 to replace the rank of ensign , although it had long been used in the Royal Artillery, Royal...
s; on 1 January 1945 Rejewski, and presumably also Zygalski, were promoted to lieutenant
Lieutenant
A lieutenant is a junior commissioned officer in many nations' armed forces. Typically, the rank of lieutenant in naval usage, while still a junior officer rank, is senior to the army rank...
.
Enigma decryption, however, had become an exclusively British and American domain; the two mathematicians who, with their late colleague, had laid the foundations for Allied Enigma decryption were now excluded from making further contributions to their métier. British cryptologist Alan Stripp suggests that by that time, at Bletchley Park
Bletchley Park
Bletchley Park is an estate located in the town of Bletchley, in Buckinghamshire, England, which currently houses the National Museum of Computing...
, "very few even knew about the Polish contribution" because of the strict secrecy and the "need-to-know" principle. Stripp comments further that "Setting them to work on the Doppelkassetten system was like using racehorses to pull wagons."
Back in Poland
On 21 November 1946, Rejewski, having been on 15 November discharged from the Polish Army in Britain, returned to Poland to be reunited with his wife, Irena Maria Rejewska (née Lewandowska, whom Rejewski had married on 20 June 1934) and their son Andrzej (Andrew, born 1936) and daughter Janina (Jeanne, born 1939, who would later follow in her father's footsteps to become a mathematician).Rejewski took a position in Bydgoszcz as director of the sales department at a cable manufacturing company, Kabel Polski (Polish Cable).
Between 1949 and 1958, Rejewski was repeatedly investigated by the Polish Security Service but never divulged that he had worked on Enigma; in 1950 they demanded that he be fired from his employment. He then worked briefly as a director at the State Surveying Company, then at the Association of Polish Surveyors. From 1951 to 1954 he worked at the Association of Timber and Varied Manufactures Cooperatives. From 1954 until his retirement on a disability pension in February 1967, he was director of the inspectorate of costs and prices at a Provincial Association of Labor Cooperatives.
In 1969 Rejewski and his family moved back to Warsaw
Warsaw
Warsaw is the capital and largest city of Poland. It is located on the Vistula River, roughly from the Baltic Sea and from the Carpathian Mountains. Its population in 2010 was estimated at 1,716,855 residents with a greater metropolitan area of 2,631,902 residents, making Warsaw the 10th most...
, to the apartment that he had acquired in May 1939 with financial help from his father-in-law. (After the Germans suppressed the 1944 Warsaw Uprising, they had sent Mrs. Rejewska and her children, along with other Warsaw survivors, west, where the family had eventually found refuge with her parents in Bydgoszcz.)
Rejewski understandably took satisfaction from his accomplishments in breaking the German Enigma cipher
Enigma machine
An Enigma machine is any of a family of related electro-mechanical rotor cipher machines used for the encryption and decryption of secret messages. Enigma was invented by German engineer Arthur Scherbius at the end of World War I...
for nearly seven years (beginning in December 1932) prior to the outbreak of World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
and then into the war, in personal and teleprinter
Teleprinter
A teleprinter is a electromechanical typewriter that can be used to communicate typed messages from point to point and point to multipoint over a variety of communication channels that range from a simple electrical connection, such as a pair of wires, to the use of radio and microwave as the...
collaboration with Bletchley Park
Bletchley Park
Bletchley Park is an estate located in the town of Bletchley, in Buckinghamshire, England, which currently houses the National Museum of Computing...
, at least until the 1940 fall of France. In 1942, at Uzès
Uzès
Uzès is a commune in the Gard department in southern France.It lies about 25 km north-northeast of Nîmes.-History:Originally Ucetia, Uzès was a small Gallo-Roman oppidum, or administrative settlement. The town lies at the source of the Eure, from where a Roman aqueduct was built in the first...
, Vichy France
Vichy France
Vichy France, Vichy Regime, or Vichy Government, are common terms used to describe the government of France that collaborated with the Axis powers from July 1940 to August 1944. This government succeeded the Third Republic and preceded the Provisional Government of the French Republic...
, he wrote a "Report of Cryptologic Work on the German Enigma Machine Cipher." Before his retirement in 1967 a quarter-century later, he began writing his "Memoirs of My Work in the Cipher Bureau of Section II of the [Polish] General Staff," which were purchased by the Military Historical Institute, located in Warsaw.
Rejewski must often have wondered, after the 1940 French debacle, what use Alan Turing
Alan Turing
Alan Mathison Turing, OBE, FRS , was an English mathematician, logician, cryptanalyst, and computer scientist. He was highly influential in the development of computer science, providing a formalisation of the concepts of "algorithm" and "computation" with the Turing machine, which played a...
(who had visited the Polish cryptologists outside Paris
Paris
Paris is the capital and largest city in France, situated on the river Seine, in northern France, at the heart of the Île-de-France region...
) and Bletchley Park
Bletchley Park
Bletchley Park is an estate located in the town of Bletchley, in Buckinghamshire, England, which currently houses the National Museum of Computing...
, had ultimately made of the Polish discoveries and inventions. For nearly three decades after the war, little was publicly known due to a ban that had been imposed on 25 May 1945 by British Prime Minister Winston Churchill
Winston Churchill
Sir Winston Leonard Spencer-Churchill, was a predominantly Conservative British politician and statesman known for his leadership of the United Kingdom during the Second World War. He is widely regarded as one of the greatest wartime leaders of the century and served as Prime Minister twice...
.
Ladislas Farago
Ladislas Farago was a military historian and journalist who published a number of best-selling books on history and espionage, especially concerning the World War II era....
's 1971 best-seller The Game of the Foxes presented a garbled account of Ultra's origins: "Commander Denniston
Alastair Denniston
Commander Alexander Guthrie Denniston CMG CBE RNVR was a British codebreaker in Room 40 and first head of the Government Code and Cypher School and field hockey player...
went clandestinely to a secluded Polish castle [!] on the eve of the war [to pick up an Enigma, "the Wehrmacht's top system" during World War II]. Dilly Knox later solved its keying..." Still, this was closer to the truth than most of the British and American accounts that would follow after 1974. Their authors were at a disadvantage: they did not know that the founder of Enigma decryption, Marian Rejewski, was still alive and alert and that historical confabulation was therefore hazardous.
With Gustave Bertrand
Gustave Bertrand
Gustave Bertrand 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...
's 1973 publication of his Enigma, substantial information about the origins of Ultra began to seep out to the broader world public. With F.W. Winterbotham's 1974 best-seller The Ultra Secret, the dam began to burst. Still, many authors likewise aspired to best-sellerdom and were not averse to filling gaps in their information with whole-cloth fabrications. Rejewski fought a gallant (if into the 21st century still not entirely successful) fight to get the truth before the public. He published a number of papers on his cryptologic work and contributed generously to articles, books and television programs. He was interviewed by scholars, journalists and television crews from Poland, East Germany, the United States, Britain, Sweden, Belgium, the Soviet Union, Yugoslavia and Brazil.
He maintained a lively correspondence with his wartime French host, General Gustave Bertrand
Gustave Bertrand
Gustave Bertrand 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...
, and at the General's bidding began translating Bertrand's Enigma into Polish. A few years before his death, at the request of the Józef Piłsudski Institute of America, Rejewski broke enciphered correspondence of Józef Piłsudski and his fellow Polish Socialist
Polish Socialist Party
The Polish Socialist Party was one of the most important Polish left-wing political parties from its inception in 1892 until 1948...
conspirators from 1904. On 12 August 1978, a year and a half before his death, he received the Officer's Cross of the Order of Polonia Restituta
Polonia Restituta
The Order of Polonia Restituta is one of Poland's highest Orders. The Order can be conferred for outstanding achievements in the fields of education, science, sport, culture, art, economics, defense of the country, social work, civil service, or for furthering good relations between countries...
.
Rejewski, who had been suffering from heart disease
Heart disease
Heart disease, cardiac disease or cardiopathy is an umbrella term for a variety of diseases affecting the heart. , it is the leading cause of death in the United States, England, Canada and Wales, accounting for 25.4% of the total deaths in the United States.-Types:-Coronary heart disease:Coronary...
, died of a heart attack
Myocardial infarction
Myocardial infarction or acute myocardial infarction , commonly known as a heart attack, results from the interruption of blood supply to a part of the heart, causing heart cells to die...
at his home on 13 February 1980, aged 74. He was buried with military honors at Warsaw
Warsaw
Warsaw is the capital and largest city of Poland. It is located on the Vistula River, roughly from the Baltic Sea and from the Carpathian Mountains. Its population in 2010 was estimated at 1,716,855 residents with a greater metropolitan area of 2,631,902 residents, making Warsaw the 10th most...
's Powązki Military Cemetery
Powązki Military Cemetery
Powązki Military Cemetery is an old military cemetery located in the Wola district, western part of Warsaw, Poland. The cemetery is often confused with the older Powązki Cemetery, known colloquially as "Old Powązki"...
.
In 2000, Rejewski and his colleagues Zygalski and Różycki were posthumously awarded the Grand Cross of the Order of Polonia Restituta
Polonia Restituta
The Order of Polonia Restituta is one of Poland's highest Orders. The Order can be conferred for outstanding achievements in the fields of education, science, sport, culture, art, economics, defense of the country, social work, civil service, or for furthering good relations between countries...
. On 4 July 2005, Rejewski's daughter Janina Sylwestrzak received on his behalf, from the British Chief of the Defence Staff, the War Medal 1939–1945
War Medal 1939–1945
The War Medal 1939–1945 was a British decoration awarded to those who had served in the Armed Forces or Merchant Navy full-time for at least 28 days between 3 September 1939 and 2 September 1945. In the Merchant Navy, the 28 days must have been served at sea...
.
In 1979 Rejewski and his colleagues became heroes of Sekret Enigmy ("The Enigma Secret"), a Polish-cryptologists-and-German-spies movie thriller about the Poles' solution of the German Enigma cipher
Enigma machine
An Enigma machine is any of a family of related electro-mechanical rotor cipher machines used for the encryption and decryption of secret messages. Enigma was invented by German engineer Arthur Scherbius at the end of World War I...
. Late 1980 also saw a Polish TV series
Serial (radio and television)
Serials are series of television programs and radio programs that rely on a continuing plot that unfolds in a sequential episode by episode fashion. Serials typically follow main story arcs that span entire television seasons or even the full run of the series, which distinguishes them from...
with a similar theme, Tajemnice Enigmy ("The Secrets of Enigma").
In 1983, a Polish postage stamp
Postage stamp
A postage stamp is a small piece of paper that is purchased and displayed on an item of mail as evidence of payment of postage. Typically, stamps are made from special paper, with a national designation and denomination on the face, and a gum adhesive on the reverse side...
marked the 50th anniversary of the German military Enigma's first solution; the First Day Cover featured likenesses of the three mathematician-cryptologists. Memorials to the trio have been unveiled at Bletchley Park
Bletchley Park
Bletchley Park is an estate located in the town of Bletchley, in Buckinghamshire, England, which currently houses the National Museum of Computing...
and the Polish Embassy in the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
, and at Uzès
Uzès
Uzès is a commune in the Gard department in southern France.It lies about 25 km north-northeast of Nîmes.-History:Originally Ucetia, Uzès was a small Gallo-Roman oppidum, or administrative settlement. The town lies at the source of the Eure, from where a Roman aqueduct was built in the first...
in France. In Rejewski's home city of Bydgoszcz, a street and school have been named for him, a plaque placed on the building where he had lived, and a sculpture commissioned (pictured above). In 2005 a postcard (below) was issued, commemorating the centennial of Rejewski's birth.
In 2007, a three-sided bronze monument was dedicated before Poznań Castle
Imperial Castle in Poznan
The Imperial Castle in Poznań, popularly called Zamek , is a palace in Poznań, Poland. It was constructed in 1910 by Franz Schwechten for William II, German Emperor, with significant input from William himself...
. Each side bears the name of one of the three mathematics students who had attended the 1929 cryptology course and subsequently collaborated on breaking the Enigma cipher.
See also
- Cryptanalysis of the EnigmaCryptanalysis of the EnigmaCryptanalysis of the Enigma enabled the western Allies in World War II to read substantial amounts of secret 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...
- List of cryptographers
- Polish contribution to World War II#Intelligence
- Polish School of MathematicsPolish School of MathematicsThe Polish School of Mathematics refers to the mathematics community that flourished in Poland in the 20th century, particularly during the Interbellum between World Wars I and II.- Overview :The Polish School of Mathematics subsumed:...
- Tadeusz Pełczyński#Enigma
Footnote citations
External links
- The Enigma Code Breach by Jan Bury: an account of the Polish role
- The Breaking of Enigma by the Polish Mathematicians by Tony Sale
- How Mathematicians Helped Win WWII — National Security Agency
- Enigma documents
- Rejewski biography, University of St Andrews
- Marian Rejewski and the First Break into Enigma
- Photographs of Rejewski: http://ww2.tvp.pl/2739,20050927249915.strona, http://www.wiadomosci.tvp.com.pl/389,20050704221744.strona, http://ww6.tvp.pl/389,20051013256196.strona