John Tiltman

From left: British cryptanalysts Harry Hinsley , Sir Edward Travis , John Tiltman, Washington 1945

Brigadier General John Hessell Tiltman (born May 25, 1894 in London , † August 10, 1982 in Hawaii ) was a British officer , secret service employee and cryptanalyst . During the Second World War , as chief cryptanalyst at Bletchley Park, he contributed significantly to the deciphering of the encrypted secret German communications.

Life

Army service in the First World War

Scottish Regiment tactical mark

John Tiltman's parents were both from Scotland , he was born in England, in the British capital London , but felt himself to be Scottish. With the outbreak of World War I in 1914, Tiltman served in a Scottish regiment of the British Army, the " King's Own Scottish Borderers ". He was wounded at the front in France and received the " Military Cross " (German: Military Cross ) as an award for bravery .

Cryptanalyst in India

Tiltman's career as a cryptanalyst began between 1921 and 1929 while he was serving at the British Army Headquarters in India in the city of Shimla (then spelled Simla). There he worked successfully in a small group of code breakers who succeeded in deciphering the diplomatic communications that Russian agencies sent from Moscow in encrypted form to Kabul in Afghanistan and Tashkent in Uzbekistan . During this time, in addition to actually cracking the code, he got to know almost all aspects of cryptanalytic work, including the field of Signals Intelligence (SI), which also includes interception techniques and traffic analysis. He himself later described this circumstance as a particularly happy and important experience for his later work.

Code breakers in Bletchley Park

The mansion (Engl. The mansion ) of Bletchley Park was the headquarters of the British code breaker and is now a museum

In the following decade he initially worked as a civilian employee of the War Ministry in the Government Code and Cypher School (abbreviation: GC&CS; German for example: "Staatliche Code- und Chiffrenschule"), before returning to the rank of captain (corresponds to the German rank of captain ) was called to active service. The name GC&CS was the code name of the military agency that successfully deciphered German communications during World War II .

John Tiltman, who had learned cryptanalysis “from scratch”, was valued at Bletchley Park as one of the most outstanding specialists in manual keying. One of his accomplishments was the breaking of a hand key used in the German army and in the security service (SD) during the Second World War, known as a " double box key ", which was a modification of the Playfair encryption invented in the 19th century .

Tiltman was the head of the Army section (" Head of the Army section ") of Bletchley Park, which mainly included " Hut Three " and " Hut Six " (German: Baracke 3 und Barracke 6), and was directly subordinate to the director of Bletchley Park, Alastair Denniston . In his role, he not only performed important management tasks, but also successfully dealt with the deciphering of machine encryption procedures. He managed to break the older version of the German rotor key machine Enigma , also known as the "Reichsbahn-Enigma" , used by the Deutsche Reichsbahn . This method was called " Rocket " (German: rocket) in Bletchley Park after the early steam locomotive The Rocket . In contrast to the Enigma variants used by the military, such as Enigma I and Enigma-M4 , the Reichsbahn-Enigma did not have a plug board and was therefore cryptographically less secure.

Together with Bill Tutte , the Colonel at the time (equivalent to the German rank of Colonel ) John Tiltman also worked on the deciphering of the encrypted German telex , which was encrypted by the German authorities using the Lorenz key suffix SZ 42 and to which the British code breakers the code name " Tunny " (German: tuna) had given. In the autumn of 1941, after two weeks of laborious manual labor, he succeeded in deciphering two German telex messages encrypted with the key extension. He took advantage of a fatal mistake made by a German intelligence soldier who accidentally encrypted two messages with the same key. In order to routinely break this German encryption method , the British cryptanalysts later used the world's first programmable electronic digital computer , called “ Colossus ”, which was developed and manufactured especially for this purpose in Bletchley Park during World War II.

In 1944 Tiltman was promoted to brigadier (equivalent to the German rank of brigadier general ) and appointed deputy director of the GC&CS, which was now headed by Sir Edward Travis .

After the Second World War

After the war, " The Brig ", as John Tiltman was called respectfully in reference to his military rank, became deputy head of the Government Communications Headquarters ( GCHQ ). This is the successor organization to GC&CS, which still exists today as the UK's cryptography agency , while Bletchley Park has since been converted into a museum. In 1949 Tiltman liaison officer (was Senior Liaison Officer GCHQ ) in the Army Security Agency (German: Army Security Agency) of the Army of the United States . He retired in 1954 but remained committed to cryptography. After being inspired by his friend William Friedman , one of the most outstanding American cryptanalysts, Tiltman spent several years trying to decipher the Voynich manuscript , a mysterious ancient document that was written in an unknown script. From 1964 to 1980 he worked as a researcher and advisor at the National Security Agency (NSA), now the US National Security Agency .

John Tiltman spent sixty years of his life at the forefront of cryptological research and development. Starting with manual encryption methods of the early twentieth century, such as the double-box method, to Rotor encryption machines, such as the Enigma and the Lorenz key addition, to modern cryptographic methods of the NSA, his life span encompassed a wide range of cryptography, cryptanalysis and signals intelligence as hardly any other cryptologist was granted.

In 1980, John Tiltman moved to Hawaii to be around his daughter Tempe Denzer. He died there on August 10, 1982 at the age of 88.

Posthumous honor

John Tiltman in the Hall of Honor picture gallery (bottom row, far left)

On September 1, 2004 Brigadier General John Tiltman was inducted into the Hall of Honor (German: Ehrenhalle) of the National Security Agency. The peculiarity of this posthumous award is underlined by the fact that he was the first non-US-American to be honored in this form.

literature

• Friedrich L. Bauer : Deciphered Secrets. Methods and maxims of cryptology. 3rd, revised and expanded edition. Springer, Berlin et al. 2000, ISBN 3-540-67931-6 .
• Francis Harry Hinsley , Alan Stripp: Codebreakers - The inside story of Bletchley Park . Oxford University Press, Reading, Berkshire 1993. ISBN 0-19-280132-5
• Gordon Welchman : The Hut Six Story - Breaking the Enigma Codes . Allen Lane, London 1982; Cleobury Mortimer M&M, Baldwin Shropshire 2000. ISBN 0-947712-34-8

Web links

• John Tiltman in the honor roll (Roll of Honor) of Bletchley Park
• Ralph Erskine : Brigadier John Tiltman: One of Britain's Finest Cryptologists . Cryptologia 27 (4), October 2003. pp. 289-318.
• Brigadier John Tiltman in the NSA Hall of Honor (with photo by John Tiltman)

supporting documents

1. ^ Francis Harry Hinsley, Alan Stripp: Codebreakers - The inside story of Bletchley Park . Oxford University Press, Reading, Berkshire 1993, p. 77. ISBN 0-19-280132-5
2. ^ Francis Harry Hinsley, Alan Stripp: Codebreakers - The inside story of Bletchley Park . Oxford University Press, Reading, Berkshire 1993, p. 196. ISBN 0-19-280132-5
3. ^ Gordon Welchman: The Hut Six Story - Breaking the Enigma Codes . Allen Lane, London 1982; Cleobury Mortimer M&M, Baldwin Shropshire 2000, p. 57. ISBN 0-947712-34-8
4. ↑ Friedrich L. Bauer: Deciphered secrets. Methods and maxims of cryptology. 3rd, revised and expanded edition. Springer, Berlin et al. 2000, p. 68.
5. ^ Gordon Welchman: The Hut Six Story - Breaking the Enigma Codes . Allen Lane, London 1982; Cleobury Mortimer M&M, Baldwin Shropshire 2000, p. 77. ISBN 0-947712-34-8
6. ↑ Friedrich L. Bauer: Deciphered secrets. Methods and maxims of cryptology. 3rd, revised and expanded edition. Springer, Berlin et al. 2000, p. 378.
7. ↑ David H. Hamer , Geoff Sullivan , Frode Weierud : Enigma Variations - An Extended Family of Machines . Cryptologia. Rose-Hulman Institute of Technology. Taylor & Francis, Philadelphia PA 22.1998,1 (July), pp. 2ff, ISSN  0161-1194 . Accessed: March 26, 2008. PDF; 0.1 MB ( Memento of the original from February 13, 2012 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. 
8. ↑ Friedrich L. Bauer: Deciphered secrets. Methods and maxims of cryptology. 3rd, revised and expanded edition. Springer, Berlin et al. 2000, p. 388.