Marian Rejewski, Jerzy Różycki, and Henryk Zygalski. The mathematicians who broke the Enigma code.

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Milena Skulimowska

 Marian Rejewski, Jerzy Różycki, and Henryk Zygalski. The mathematicians who broke the Enigma code.

 The story of solving the code of Enigma, a German cypher device used during the Second World War to encrypt confidential messages, was for years, and remains, a subject of interest for researchers and authors, and even moviemakers. The intelligence gathered from the decoded messages gave the Allies an advantage and had a significant impact on the outcome of the War. In recent years Dermot Turing, a British author, in his book X, Y and Z: The Real Story of How Enigma Was Broken (2018), describes the cooperation of French, British, and Polish secret services to solve the secret of the Enigma machine. He drew attention to the role played in this process by three Polish mathematicians from the University of Poznań, Marian Rejewski, Jerzy Różycki, and Henryk Zygalski, who were able to solve the pre-war version of the Enigma machine and read encrypted messages.

The Germans had begun to develop the Enigma machine around 1919 and it became the coding method for the German navy in 1926. In 1928 the Poles started to intercept German radio messages coded by the Enigma machine. The Cypher Bureau of the General Staff of the Polish army, seeing a potential for using the mathematical approach for codebreaking, organised in January 1929 a course on the basics of cryptology for a selected group of mathematics students from the University of Poznań. Marian Rejewski, Jezry Różycki, and Henryk Zygalski attended that course and it allowed them to get recruited to work for the Polish military intelligence.

The purpose of this paper is to provide a summary biographies of the three Polish mathematicians and their input into solving the Enigma code.

Marian Rejewski

Marian Adam Rejewski was born on 16 August 1905 in Bromberg, German Empire (now Bydgoszcz, Poland) and died on 13 February 1980 in Warsaw, Poland. Rejewski’s parents were Józef Rejewski, a tobacco merchant, and Matylda Thoms.

In 1923 and entered the Faculty of Mathematics and Natural Sciences of the University of Poznań to study mathematics. He was awarded a master’s degree on 1 March 1929 for his thesis Theory of double periodic functions of the second and third kind and its applications. That year in January he attended a course on the basics of cryptology organised by Cypher Bureau, an intelligence agency within the General Staff of the Polish Army. He then went to Göttingen University in Germany to enroll in a two-year actuarial statistics course. However, he did not complete the course. In the summer of 1930, he was offered a position as a teaching assistant in mathematics at the University of Poznań, which he accepted.

Shortly after, he began to work for the Poznań Branch of the Cypher Bureau. After the Poznań Branch of the Cypher Bureau was disbanded in the summer of 1932 and, in September 1932 Rejewski transferred to the Cypher Bureau in Warsaw.  Rejewski began work decyphering the code of the Engma in late October or early November 1932. With the help of information provided by French intelligence, he was able to reconstruct the Enigma machine in December 1932. At the beginning of 1933, he was joined by Różycki and Zygalski in the effort to devise methods of decyphering messages encrypted by Enigma on routine bases.  He applied statistical analysis to uncover Enigma’s cryptographic techniques allowing the machine to be solved. His insight and unconventional approach to code-breaking based on permutation theory produced a solution that had evaded his French and British peers.

On 20 June 1934 Rejewski married Irena Maria Lewandowska. They had two children, Andrzej born in 1936, and Janina born in 1939. During this time, he continued to work at the Cypher Bureau in Warsaw. By January 1938 the team of Polish mathematicians was able to read about three-quarters of the Enigma messages which were given to them for decoding.

After Germany invaded Poland on 1 September 1939, Rejewski, along with Różycki and Zygalski, was evacuated to Romania (although his wife and family remained in Poland) and then to Paris which they reached before the end of September. In October they joined a decoding unit operating under the cryptonym ‘Bruno’ at the Château de Vignolles northeast of Paris and by the end of the year, they were again managing to decode messages sent by the German Enigma machines.

After the German troops entered Paris in June 1940 Rejewski and his colleagues were evacuated to Algeria. After a new French government collaborating with Germany was established in Vichy, Rejewski and his colleagues returned to Vichy France (10 July 1940 – 9 August 1944) in September 1940. He worked there together with Zygalski and Różycki for a secret cryptology unit operating under a cryptonym ‘Cadix’.  Every few months, they would travel to work in a similar decoding center operating in Algeria. During one of such journeys on 9 January 1942, Jerzy Różycki died, after the ship he was on sunk near the Balearic Islands.

After Germany occupied Vichy France the unit at the Château des Fouzes had to evacuate in November 1942. Rejewski and Zygalski moved around across southern France evading capture. They eventually decided to cross the Pyrenees. Despite being robbed by their guide at gunpoint, they reached Spain, only to be put in prison. From January to March 1943 they were held at Séo de Urgel, then they were transferred to a prison in Lerida. On 24 May they were released and sent to Madrid. From there they made their way to Portugal. From Portugal they traveled on board a Royal Navy ship to Gibraltar, to be flown to Britain where they arrived in August 1943. Rejewski then joined the Polish Army in Britain and remained there for the rest of the war, working on decoding.

In November 1946 Rejewski was released from the military service and returned to Poland to be reunited with his family, which was still living in Bydgoszcz. Following his return, Rejewski decided not to resume his academic career and took a job in the department of sales at Kabel Polski (Polish Cable) company, where he worked until 1950. Then he worked as a clerk until he retired in 1967. Between 1949–1958, Rejewski was investigated by the Security Service (Służba Bezpieczenstwa, SB), an agency combining functions of the secret police and intelligence service.  However, at that time almost nothing was known about his wartime fate and work on Enigma. Up to the time of his retirement, Rejewski had maintained complete secrecy about his work in cryptology.

In 1969 Rejewski and his family moved to Warsaw and the full story of his involvement with the Enigma cypher breaking emerged in 1973. This led him to appear in the media. He wrote several technical articles and memoirs from his time in cryptology. Rejewski died on 13 February 1980 at his home in Warsaw following a heart attack and was buried with full military honours at Powązki Military Cemetery


Jerzy Różycki

Jerzy Witold Różycki was born on 24 July 1909 in Olszana, Russian Empire (now Vilshana, Ukraine), and died on 9 January 1942 on the Mediterranean Sea near Balearic Island. He was the fourth and the youngest child of Zygmunt Różycki, a pharmacist and graduate of Saint Petersburg University, and his wife Wanda Leopolda Benita. He spent his early life attending a school for pupils of Polish origin in Kyiv. However in 1918, before he was able to graduate, he moved together with his parents to Wyszkow in Poland. He attended secondary school there, graduating in 1926.

In 1927 he entered the Faculty of Mathematics and Natural Sciences of the University of Poznań where she studied mathematics and geography. On 19 February 1932, he was awarded a master’s degree in mathematics, and on 13 December 1937 master’s in geography. While studying at the University of Poznań he joined the Student Corporation ‘Chrobia’ (Korporacja Academicka Chrobia), a type of fraternity, which was closely connected with the military circles in Poznań.

Różycki’s engagement with the Polish military intelligence started in January 1929 when he attended the cryptology course run by Polish Cypher Bureau. While still a student, Różycki was employed in the Poznań branch of the Cypher Bureau. There he worked on decoding German radio and telephone messages. During 1929-32, together with Marian Rejewski and Henryk Zygalski, he dealt mainly with the decryption of the code of the German navy. After the Poznań branch of the Cypher Bureau was disbanded in 1932, he began working at the Cypher Bureau in Warsaw.

After Rejewski had reconstructed the German military Enigma machine in December 1932, Różycki and Zygalski started to work with him on the ongoing development of methods and equipment to exploit Enigma decryption as a source of intelligence. Różycki invented the so-called ‘clock method’, for determining the rotor setting in the Enigma machine. The team continued the work on decrypting messages sent through Enigma until the summer of 1939 when they passed their discoveries to the British.

After the German invasion, in September 1939 Różycki had to leave the country,  while his family, a son, and wife Maria Barbara Majka, whom he married a year before remained in Poland. Różycki together with Rejewski and Zygalski evacuated through Romania to France. In October 1939, the three Polish mathematicians began decoding German cyphers at the decoding centre ‘Bruno’ which was established at the Château de Vignolles in Gretz-Armainvillers close to Paris. After German troops entered Paris and France surrendered in June 1940, Różycki and his two colleagues were transferred to Algeria. After a few months spent in Algeria, they return to Vichy France to work at the decoding centre ‘Cadix’  that operated in secret at the Château Les Fouzes near Usès in Provence from October 1940 to November 1942.

In the summer of 1941, Różycki was delegated back to Algeria to work on reading the dispatches sent by the German and Italian troops operating in North Africa. He remained there until early January 1942. On his return to France, he boarded the Lamoricière, a steamer operated by the Compagnie Générale Transatlantique, in Algiers heading for Marseille. The ship had 272 passengers, 88 of whom were military personnel. It sank in a storm near Balearic Islands on 9 January 1942 but the circumstances have never been entirely clear. It is known that it changed course on 8 January when, during a storm, it received a signal of distress from another ship. The Lamoricière experienced some problems with coal and began to sink approximately ten kilometers from Cape Favaritx in the northeast of Menorca. There were 93 survivors of the disaster, but sadly Różycki drowned. His body was never found.

Henryk Zygalski

 Henryk Michał Zygalski was born 15 July 1908 in Posen, German Empire, (now Poznań, Poland) and died on 30 August 1978 in Liss, Hempshire, United Kingdom. Zygalski’s parents were Michał Zygalski who run a tailor shop in Pznan and Stanisława Kielisz. He attended the St Mary Magdalene Gymnasium in Poznań from which he graduated in 1926. Later that year Zygalski entered the Faculty of Mathematics and Natural Sciences of Poznań University. He passed his final master’s degree examinations in December 1931.

After attending a course on the basics of cryptology course orgised by the Polish Cypher Bureau in January 1929, he worked for the Poznań Branch of Cypher Bureau until it was disbanded in the summer of 1932. In September 1932 he began working for the Cypher Bureau in Warsaw. He worked there together with Marian Rejewski and Jerzy Różycki on decyphering German Navy code. After Rejewski reconstructed the Enigma machine Zygalski together with Różycki joined Rejewski in working on devising the method of decrypting messages sent encoded by Enigma.

In late 1938, in response to growing complexities in German encryption procedures, Zygalski designed the ‘perforated sheets’, also known as ‘Zygalski sheets’, a manual grid-based cardboard system used to determine Enigma’s settings. Zygalski sheets, together with reconstructed version of the Enigma machine and other findings were passed to the British in July 1939 and were later used at Bletchley Park, the British center for codebreaking and cryptanalysis during the Second World War.

In September, following the German attack on Poland, Zygalski, Rejewski, and Rózycki were told to evacuate from Warsaw. With German armies attacking from the west, they went east crossing the border into Romania on 17 September. From there they made their way to France. In October 1939, Zygalski, together with the other two Polish mathematicians, began decoding German messages at a decoding centre ‘Bruno’ at Château de Vignolles in Gretz-Armainvillers northeast of Paris.

As a result of the German attack on France Bruno was evacuated on 9 June 1940. On 24 June Zygalski and his two colleagues were moved to Algeria. They returned to Vichy France in September 1940. They were based at a decoding center ‘Cadix’ outside the town of Uzès in southern France which was in operation until 1942. During that time they were also required to spend some time working at a decoding centre in Algeria where they were gathering information in preparation for the Allied invasion of North Africa. On 9 January 1942, Różycki died when the ship he was on sank while crossing the Mediterranean from Algiers to France.

Following the German occupation of Vichy France in November 1942, Zygalski and Rejewski had to flee again. In January 1943 they reached the Spanish border accompanied by a guide who robbed them at gunpoint during this journey. Once in Spain, Zygalski and Rejewski were arrested and from January to May 1943 were held in prison in Séo de Urgel and Lerida. On 24 May they were released and sent to Madrid. From there they traveled to Portugal to eventually find there their way via Gibraltar to Britain where they arrived in August 1943.

Once in Britain, Zygalski and Rejewski became part of the Polish battalion stationed at Boxmoor near London. They did no further work on the Enigma codes but they did work on breaking other German cyphers for the rest of the war. It remains unclear why the two Polish mathematicians were not allowed to join the work of decoding Enigma messages carried by Bletchley Park, particularly since they had collaborated with the British while in France.

After the war ended Zygalski, decided to remain in Britain working as a lecturer in mathematics at the University of Surrey (between 1956 and 1966 known as Battersea College of Technology, and before that as Battersea Polytechnic Institute).  His academic carrier ended in 1968 due to health problems. In 1977 he was awarded an honorary title by the Polish University Abroad in London for his achievements. He died on 30 August 1978 in Liss, Hampshire, United Kingdom. His body was cremated and the ashes were scattered at the Garden of Remembrance at the crematorium in Chichester, West Sussex.

On 6 September  2019, at the Church of St. Peter and St. Paul in Krakow, a ceremony was held to commemorate Polish cryptologists, Marian Rejewski, Jerzy Różycki, and Henryk Zygalski. A memorial sarcophagus was erected at the National Pantheon in the vault of the church, containing urns with soil from places associated with the death or burial of Polish cryptologists, i.e. Powązki Cemetery in Warsaw, the bottom of the Mediterranean Sea,  Chichester


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