Ralph Paterson Tester (2 June 1902 – May 1998) was an administrator at

Bletchley Park Bletchley Park is an English country house and estate in Bletchley, Milton Keynes ( Buckinghamshire) that became the principal centre of Allied code-breaking during the Second World War. The mansion was constructed during the years followin ...

, the British

codebreaking Cryptanalysis (from the Greek ''kryptós'', "hidden", and ''analýein'', "to analyze") refers to the process of analyzing information systems in order to understand hidden aspects of the systems. Cryptanalysis is used to breach cryptographic sec ...

station during

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing ...

. He founded and supervised a section named the ''

Testery The Testery was a section at Bletchley Park, the British codebreaking station during World War II. It was set up in July 1942 as the "FISH Subsection" under Major Ralph Tester, hence its alternative name. Four founder members were Tester himself ...

'' for breaking Tunny (a

Fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of ...

cipher).

Background

The

Lorenz cipher The Lorenz SZ40, SZ42a and SZ42b were German rotor stream cipher machines used by the German Army during World War II. They were developed by C. Lorenz AG in Berlin. The model name ''SZ'' was derived from ''Schlüssel-Zusatz'', meaning ''cipher ...

machine had twelve wheels, and was thus most advanced, complex, faster and far more secure than the three-wheeled

Enigma Enigma may refer to: *Riddle, someone or something that is mysterious or puzzling Biology *ENIGMA, a class of gene in the LIM domain Computing and technology * Enigma (company), a New York-based data-technology startup * Enigma machine, a family ...

. Lorenz was used to encipher top-secret messages between German Army H.Q. in

Berlin Berlin ( , ) is the capital and List of cities in Germany by population, largest city of Germany by both area and population. Its 3.7 million inhabitants make it the European Union's List of cities in the European Union by population within ci ...

, and the top generals and field-marshals on all fronts, including

Adolf Hitler Adolf Hitler (; 20 April 188930 April 1945) was an Austrian-born German politician who was dictator of Nazi Germany, Germany from 1933 until Death of Adolf Hitler, his death in 1945. Adolf Hitler's rise to power, He rose to power as the le ...

himself.

Career

Before World War II, Tester was an accountant who had worked extensively in

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...

and as a result was very familiar with the

German language German ( ) is a West Germanic language mainly spoken in Central Europe. It is the most widely spoken and official or co-official language in Germany, Austria, Switzerland, Liechtenstein, and the Italian province of South Tyrol. It is als ...

and culture.Paul Gannon, ''Colossus: Bletchley Park's Greatest Secret'', 2006, p. 168, Atlantic Books, . He held a senior position in the accountancy division of

Unilever Unilever plc is a British multinational consumer goods company with headquarters in London, England. Unilever products include food, condiments, bottled water, baby food, soft drink, ice cream, instant coffee, cleaning agents, energy dri ...

. On the outbreak of war, he worked for the BBC Monitoring Service which listened in to German public radio broadcasts.

Bletchley Park

Tester was recruited to Bletchley Park, and during later 1941 became the head of a small group working on a double

Playfair cipher The Playfair cipher or Playfair square or Wheatstone–Playfair cipher is a manual symmetric encryption technique and was the first literal digram substitution cipher. The scheme was invented in 1854 by Charles Wheatstone, but bears the name of ...

used by German military police. The

was set up in July 1942 under his command. The three other original founding members,

cryptographers This is a list of cryptographers. Cryptography is the practice and study of techniques for secure communication in the presence of third parties called adversaries. Pre twentieth century * Al-Khalil ibn Ahmad al-Farahidi: wrote a (now lost) book ...

and linguists, were: Capt.

Jerry Roberts Captain Raymond C. "Jerry" Roberts MBE (18 November 1920 – 25 March 2014) was a British wartime codebreaker and businessman. During the Second World War, Roberts worked at the Government Code and Cypher School (GC&CS) at Bletchley Park f ...

Peter Ericsson Peter may refer to: People * List of people named Peter, a list of people and fictional characters with the given name * Peter (given name) ** Saint Peter (died 60s), apostle of Jesus, leader of the early Christian Church * Peter (surname), a su ...

and Maj. Denis Oswald. All four were fluent in German. The Testery used hand methods to break messages enciphered on Tunny traffic. The Testery decoded 1.5 million messages by hand within one year of its foundation. By the war's end in May 1945, the Testery had grown to nine cryptographers, with a total staff of 118 organised in three shifts. A former Testery senior codebreaker and shift leader

, recalls that, "The imperturbable, pipe-smoking Tester spoke fluent German, but did not pretend to be a codebreaker. The atmosphere in his unit was always positive and friendly, and the personnel were well selected—Tester seemed to find the right niche for everybody. Thanks to Tester's influence the work of the Testery was very well organised." Towards the end of the European war, Tester was part of a

TICOM TICOM (Target Intelligence Committee) was a secret Allied project formed in World War II to find and seize German intelligence assets, particularly in the field of cryptology and signals intelligence. It operated alongside other Western Allied ...

team, a mission sent to Germany to discover information about their communications technology, including TUNNY machines.Smith, ''Station X'', p. 203–204. After the war, Tester returned to Unilever.

References

{{DEFAULTSORT:Tester, Ralph British accountants Bletchley Park people Unilever people 1902 births 1998 deaths

Background

Career

Bletchley Park

See also

References