# Marian Rejewski

> Polish mathematician and cryptologist (1905–1980)

**Wikidata**: [Q160411](https://www.wikidata.org/wiki/Q160411)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Marian_Rejewski)  
**Source**: https://4ort.xyz/entity/marian-rejewski

## Summary

Marian Rejewski (1905–1980) was a Polish mathematician and cryptologist who is best known for breaking the German Enigma cipher in 1932, a breakthrough that profoundly influenced the course of World War II. Working for Poland's Cipher Bureau, Rejewski invented the "bomba," a mechanical codebreaking device that laid the groundwork for later Allied efforts to decrypt German communications. His pioneering work in cryptology made him one of the most important figures in the history of codebreaking and signals intelligence.

## Biography

- **Born**: August 16, 1905 (Bydgoszcz, Poland)
- **Died**: February 13, 1980 (Poland)
- **Nationality**: Polish
- **Education**: 
  - High School No. 1 in Bydgoszcz (established 1623, reorganized 1876)
  - Adam Mickiewicz University in Poznań (founded May 7, 1919)
  - University of Göttingen (founded 1734)
- **Known for**: Breaking the German Enigma cipher and inventing the "bomba" codebreaking device
- **Employer(s)**:
  - Cipher Bureau (Poland's interwar cryptology agency, founded 1919)
  - Polish Land Forces (ground warfare branch, founded 1918)
  - Adam Mickiewicz University in Poznań
  - University of Göttingen
- **Field(s)**: Mathematics, Cryptography
- **Occupation**: Mathematician, Cryptologist, Inventor
- **Citizenship**: Poland

## Contributions

Marian Rejewski's most significant contribution to cryptography and military history was his successful decryption of the German Enigma cipher in 1932. Working at Poland's Cipher Bureau, Rejewski and his colleagues Jerzy Różycki and Henryk Zygalski developed mathematical methods to break the Enigma's encryption, which was considered unbreakable at the time. Their breakthrough allowed Poland to read a significant portion of German military communications in the years leading up to World War II.

In October 1938, Rejewski invented the "bomba" (Polish for "bomb"), a mechanical device designed to automate the process of breaking Enigma encryptions. This pioneering codebreaking machine was created at the Polish Cipher Bureau and represented a major advancement in cryptanalytic technology. The principles and design of the "bomba" later influenced the development of the British Bombes at Bletchley Park during World War II.

Prior to the outbreak of World War II, Rejewski and his colleagues shared their findings with British and French intelligence agencies, providing crucial information about the Enigma cipher that would prove invaluable to Allied codebreaking efforts throughout the war. This exchange of intelligence represented one of the most significant acts of cryptographic cooperation in history.

During World War II, Rejewski continued his cryptological work, serving in the Polish armed forces and contributing to the Allied effort to decrypt German communications. His expertise and innovations played a vital role in shortening the war and saving countless lives.

## FAQs

**What was Marian Rejewski's most important achievement?**

Marian Rejewski's most important achievement was breaking the German Enigma cipher in 1932 while working for Poland's Cipher Bureau. This breakthrough allowed Poland to decrypt German military communications and provided the foundation for Allied codebreaking efforts throughout World War II.

**What was the "bomba" that Marian Rejewski invented?**

The "bomba" was a mechanical codebreaking device invented by Marian Rejewski in October 1938 at the Polish Cipher Bureau. It automated the process of breaking Enigma encryptions by testing different rotor configurations, significantly speeding up the decryption process and representing a major advancement in cryptanalytic technology.

**Where did Marian Rejewski study?**

Marian Rejewski was educated at High School No. 1 in Bydgoszcz, one of Poland's oldest educational institutions dating back to 1623. He later studied mathematics at Adam Mickiewicz University in Poznań (founded 1919) and the University of Göttingen in Germany (founded 1734).

**How did Marian Rejewski's work affect World War II?**

Rejewski's breaking of the Enigma cipher and his invention of the "bomba" had a profound impact on World War II. By providing the Allies with the ability to decrypt German communications, his work contributed to significant military victories, including the Battle of the Atlantic, and helped shorten the war by an estimated two to four years, saving millions of lives.

**What recognition did Marian Rejewski receive for his work?**

Marian Rejewski received the War Medal 1939–1945, a British campaign medal awarded for service during World War II. His contributions to cryptography were later recognized as one of the most important achievements in the history of signals intelligence.

## Why They Matter

Marian Rejewski matters because his pioneering work in breaking the Enigma cipher fundamentally altered the course of World War II and the history of cryptography. His mathematical approach to solving the Enigma, which many considered unbreakable, demonstrated the power of applying rigorous mathematical methods to cryptographic problems.

The "bomba" that Rejewski invented in 1938 represented the first mechanical device designed specifically for automated codebreaking, predating similar British and American developments by several years. When Poland was invaded in September 1939, Rejewski and his colleagues shared their findings with British and French intelligence, providing the foundation for the codebreaking operations at Bletchley Park that would become legendary under the leadership of Alan Turing.

Without Rejewski's initial breakthrough, the Allied codebreaking effort would have faced far greater obstacles, and the war's outcome might have been significantly different. His work established principles of cryptanalysis that continue to influence modern cryptography and information security. Rejewski's legacy extends beyond his wartime achievements to establishing Poland as a center of excellence in mathematics and cryptology, inspiring generations of mathematicians and computer scientists in his home country and around the world.

## Notable For

- Breaking the German Enigma cipher in 1932, the first successful decryption of what was considered an unbreakable code
- Inventing the "bomba" codebreaking device in October 1938, a pioneering mechanical codebreaking machine
- Being one of the founding figures of modern cryptanalysis and signals intelligence
- Contributing to shortening World War II by enabling Allied access to German military communications
- Being recognized with the War Medal 1939–1945 for his wartime service
- Establishing Poland's role in the history of mathematics and cryptography

## Body

### Early Life and Education

Marian Adam Rejewski was born on August 16, 1905, in Bydgoszcz, Poland, then part of the German Empire. Raised in a period when Poland had regained its independence following the partitions of the late 18th century, Rejewski developed an early interest in mathematics and problem-solving. He attended High School No. 1 in Bydgoszcz, an institution with roots dating back to 1623, which provided him with a strong educational foundation in the sciences.

Following his secondary education, Rejewski pursued higher studies in mathematics at Adam Mickiewicz University in Poznań, one of Poland's largest and most prestigious universities, founded in 1919. The university, named after Poland's national poet Adam Mickiewicz, represented the country's commitment to higher education and academic excellence in the newly independent Second Polish Republic. Rejewski also continued his mathematical studies at the University of Göttingen in Germany, one of Europe's oldest and most renowned centers for mathematical research, established in 1734.

### Career at the Cipher Bureau

After completing his studies, Rejewski joined the Cipher Bureau (Biuro Szyfrów), Poland's interwar cryptology agency established in 1919. The Cipher Bureau was tasked with intercepting and decrypting communications from neighboring countries, particularly Germany, which posed a significant security threat to Poland.

Rejewski's mathematical expertise proved invaluable in tackling the challenge of breaking the German Enigma cipher. The Enigma machine, used by the German military for encrypting communications, was considered one of the most sophisticated encryption devices of its time. Its multiple rotors and plugboard connections created billions of possible encryption combinations, making it appear theoretically unbreakable.

In 1932, Rejewski successfully cracked the Enigma cipher using mathematical analysis rather than brute force. His approach involved identifying patterns in the encrypted messages and exploiting weaknesses in the Enigma's design. This breakthrough allowed Poland to read a substantial portion of German military communications, providing the Polish government with valuable intelligence about German military intentions and deployments.

### Invention of the "Bomba"

In October 1938, Rejewski invented the "bomba" (Polish for "bomb"), a mechanical device designed to automate the process of breaking Enigma encryptions. The "bomba" worked by testing different rotor configurations of the Enigma machine, systematically eliminating possibilities until the correct settings were found. This innovation dramatically accelerated the decryption process, allowing cryptanalysts to break Enigma codes within hours rather than days or weeks.

The "bomba" represented a groundbreaking advancement in cryptanalytic technology and established the principle of using mechanical devices to assist in codebreaking. Rejewski's invention laid the conceptual foundation for the more sophisticated Bombes developed by the British at Bletchley Park during World War II, including those designed by Alan Turing.

### Pre-War Intelligence Sharing

As tensions in Europe escalated in the late 1930s, Rejewski and his colleagues at the Cipher Bureau recognized the importance of sharing their findings with Allied intelligence services. In July 1939, just weeks before Germany invaded Poland, Polish cryptologists met with representatives from Britain and France in Warsaw. During this meeting, the Poles shared their knowledge of the Enigma cipher, provided replica Enigma machines, and demonstrated the operation of the "bomba."

This exchange of intelligence proved invaluable to the Allied war effort. The British, who had struggled to make progress against the Enigma, gained crucial insights that would enable their own codebreaking operations at Bletchley Park. The Polish contribution represented one of the most significant acts of cryptographic cooperation in history.

### World War II Service

Following the German invasion of Poland in September 1939, Rejewski joined the Polish Land Forces, the ground warfare branch of Poland's military established in 1918. He continued his cryptological work, serving in units that supported the Allied intelligence effort. His expertise remained vital to the ongoing battle against German encrypted communications.

Rejewski's service during World War II was recognized with the War Medal 1939–1945, a British campaign medal awarded to those who served in the armed forces during the conflict. This award acknowledged his contributions to the Allied victory and his role in the broader effort to defeat Nazi Germany.

### Later Life and Legacy

After the war, Marian Rejewski returned to civilian life in Poland, working in various mathematical and academic positions. He passed away on February 13, 1980, leaving behind a legacy that fundamentally changed the course of modern history.

Rejewski's contributions to cryptography have been recognized as among the most important in the field's history. His work demonstrated the power of mathematical analysis in breaking complex codes and established principles that continue to influence modern cryptography and cybersecurity. The "bomba" he invented represents a pivotal moment in the development of computing and automated codebreaking, predating the computer age by more than a decade.

Today, Marian Rejewski is celebrated as a national hero in Poland and recognized worldwide as one of the founding figures of modern cryptanalysis. His pioneering work shortened World War II, saved countless lives, and demonstrated the decisive importance of intelligence in modern warfare.

## References

1. Integrated Authority File
2. MacTutor History of Mathematics archive
3. [Source](http://www.cmentarzekomunalne.com.pl/mapa/mapa.php?cment=PWZKI&rzad=4&kwatera=B%2039&grob=3&dane=+imie=Marian+nazwisko=Rejewski+check_nazwisko=on+check_ur=+rok=1800+miesiac=1+dzien=1+rok2=2021+miesiac2=10+dzien2=2+check_zg=+rok_zg1=1800+miesiac_zg1=1+dzien_zg1=1+rok_zg2=2021+miesiac_zg2=10+dzien_zg2=2+cmentarz=#kotwica)
4. Find a Grave
5. [Source](https://www.sciencedirect.com/science/article/pii/S2666389920300118)
6. International Standard Name Identifier
7. Virtual International Authority File
8. [Source](http://marianrejewski.pl/wp/biografia/)
9. Internetowy Polski Słownik Biograficzny
10. Freebase Data Dumps. 2013
11. IdRef
12. Sejm-Wielki.pl