Brigadier
Brigadier is a military rank, the seniority of which depends on the country. In some countries, it is a senior rank above colonel, equivalent to a brigadier general or commodore, typically commanding a brigade of several thousand soldiers. In ...
John Hessell Tiltman, (25 May 1894 – 10 August 1982) was a
British Army
The British Army is the principal land warfare force of the United Kingdom, a part of the British Armed Forces along with the Royal Navy and the Royal Air Force. , the British Army comprises 79,380 regular full-time personnel, 4,090 Gurk ...
officer who worked in intelligence, often at or with the
Government Code and Cypher School
Government Communications Headquarters, commonly known as GCHQ, is an intelligence and security organisation responsible for providing signals intelligence (SIGINT) and information assurance (IA) to the government and armed forces of the Unit ...
(GC&CS) starting in the 1920s. His intelligence work was largely connected with
cryptography
Cryptography, or cryptology (from grc, , translit=kryptós "hidden, secret"; and ''graphein'', "to write", or ''-logia'', "study", respectively), is the practice and study of techniques for secure communication in the presence of adver ...
, and he showed exceptional skill at
cryptanalysis
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 ...
. His work in association with
Bill Tutte
William Thomas Tutte OC FRS FRSC (; 14 May 1917 – 2 May 2002) was an English and Canadian codebreaker and mathematician. During the Second World War, he made a brilliant and fundamental advance in cryptanalysis of the Lorenz cipher, a majo ...
on the
cryptanalysis of the Lorenz cipher
Cryptanalysis of the Lorenz cipher was the process that enabled the British to read high-level German army messages during World War II. The British Government Code and Cypher School (GC&CS) at Bletchley Park decrypted many communications betwee ...
, the German teleprinter
cipher
In cryptography, a cipher (or cypher) 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''. To encipher or encode i ...
, called "
Tunny" (for tunafish) 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 following ...
, led to breakthroughs in attack methods on the code, without a computer. It was to exploit those methods, at extremely high speed with great reliability, that
Colossus
Colossus, Colossos, or the plural Colossi or Colossuses, may refer to:
Statues
* Any exceptionally large statue
** List of tallest statues
** :Colossal statues
* ''Colossus of Barletta'', a bronze statue of an unidentified Roman emperor
* ''Col ...
, the first digital programmable electronic computer, was designed and built.
Biography
Tiltman's parents were from Scotland, though he was born in London. He joined the British Army in 1914, and saw service at the front during
World War I
World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...
with the
King's Own Scottish Borderers
The King's Own Scottish Borderers (KOSBs) was a line infantry regiment of the British Army, part of the Scottish Division. On 28 March 2006 the regiment was amalgamated with the Royal Scots, the Royal Highland Fusiliers (Princess Margaret's Own ...
. He was wounded in France, and won the
Military Cross
The Military Cross (MC) is the third-level (second-level pre-1993) military decoration awarded to officers and (since 1993) other ranks of the British Armed Forces, and formerly awarded to officers of other Commonwealth countries.
The MC i ...
for bravery. He was seconded to
MI1
MI1 or British ''Military Intelligence, Section 1'' was a department of the British Directorate of Military Intelligence, part of the War Office. It was set up during World War I. It contained "C&C", which was responsible for code breaking.
I ...
shortly before it merged with
Room 40
Room 40, also known as 40 O.B. (old building; officially part of NID25), was the cryptanalysis section of the British Admiralty during the First World War.
The group, which was formed in October 1914, began when Rear-Admiral Henry Oliver, the ...
.
From 1921 to 1929, he was a cryptanalyst with the
Indian Army
The Indian Army is the land-based branch and the largest component of the Indian Armed Forces. The President of India is the Supreme Commander of the Indian Army, and its professional head is the Chief of Army Staff (COAS), who is a four- ...
at Army Headquarters, Simla. The analysts were reading Russian diplomatic cypher traffic from Moscow to Kabul, Afghanistan and Tashkent, Turkestan. Tiltman worked with a modest group of people and was involved in directing interception and traffic analysis as well as working on cyphers; he said he was exceptionally lucky to have this experience in other branches of Signals Intelligence.
After a decade as a War Office civilian at GC&CS, the interwar cryptographic organization, Tiltman was recalled to active service. Although he did not have a university education, his extensive experience of cryptanalysis was expected to be useful. He assisted in many areas of endeavour at GC&CS and was considered one of Bletchley Park's finest cryptanalysts on non-machine systems.
Tiltman was an early and persistent advocate of British cooperation with the United States in cryptology. His advocacy helped achieve smooth relations 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 opposin ...
.
In 1944, he was promoted to brigadier and appointed Deputy Director of GC&CS. He continued in 1946, as Assistant Director of the
Government Communications Headquarters
Government Communications Headquarters, commonly known as GCHQ, is an intelligence and security organisation responsible for providing signals intelligence (SIGINT) and information assurance (IA) to the government and armed forces of the Un ...
(GCHQ), successor to GC&CS.
Tiltman became Senior GCHQ Liaison Officer at the
Army Security Agency
The United States Army Security Agency (ASA) was the United States Army's signals intelligence branch from 1945 to 1976. The Latin motto of the Army Security Agency was ''Semper Vigiles'' (Vigilant Always), which echoes the declaration, often ...
in 1949. He retired as a Brigadier.
In 1951 Tiltman met
William Friedman
William Frederick Friedman (September 24, 1891 – November 12, 1969) was a US Army cryptographer who ran the research division of the Army's Signal Intelligence Service (SIS) in the 1930s, and parts of its follow-on services into the 1950s. In ...
, one of the leading scholars involved in the attempt to decipher the mysterious
Voynich manuscript
The Voynich manuscript is an illustrated codex hand-written in an otherwise unknown writing system, referred to as 'Voynichese'. The vellum on which it is written has been carbon-dated to the early 15th century (1404–1438), and stylistic anal ...
. Tiltman undertook an analysis of the ancient manuscript himself, and then in the 1970s he assigned an NSA cryptanalyst named
Mary D'Imperio to take over the Voynich crypto-analysis, when Friedman's health began becoming a challenge. D'Imperio's work resulted in the book ''The Voynich Manuscript: An Elegant Enigma,'' and is now considered one of the standard reference works on the Voynich Manuscript. Tiltman wrote the foreword to this book.
After reaching normal retirement age, Tiltman was retained by GCHQ from 1954 to 1964. From 1964 until 1980 he was a consultant and researcher at the
National Security Agency
The National Security Agency (NSA) is a national-level intelligence agency of the United States Department of Defense, under the authority of the Director of National Intelligence (DNI). The NSA is responsible for global monitoring, collecti ...
, spending in all 60 years at the cutting edge of
SIGINT
Signals intelligence (SIGINT) is intelligence-gathering by interception of ''signals'', whether communications between people (communications intelligence—abbreviated to COMINT) or from electronic signals not directly used in communication ( ...
.
Tiltman made the transition from the manual ciphers of the early 20th century to the sophisticated machine systems of the latter half of the century; he was one of a very few who were able to do so. "The Brig", as he was affectionately known in both countries, compiled a lengthy record of high achievement.
On 1 September 2004, Tiltman was inducted into the "
NSA Hall of Honor
The Hall of Honor is a memorial at the National Security Agency headquarters in Fort Meade, Maryland. It honors individuals who rendered distinguished service to American cryptology.
The Hall of Honor
The Hall of Honor is located on the grounds ...
", the first non-US citizen to be recognised in that way. The NSA commented, "His efforts at training and his attention to all the many facets that make up cryptology inspired the best in all who encountered him."
References
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{{DEFAULTSORT:Tiltman, John
1894 births
1982 deaths
King's Own Scottish Borderers officers
Recipients of the Military Cross
Commanders of the Order of the British Empire
Companions of the Order of St Michael and St George
Foreign recipients of the Legion of Merit
British Army personnel of World War I
British Army brigadiers of World War II
Bletchley Park people
GCHQ cryptographers
Pre-computer cryptographers
Foreign Office personnel of World War II
Military personnel from London