Cypher School Research Articles

Engineering Places: Bletchley Park [engineering research

The introduction of electro-mechanical encoding machines with billions of permutations at the end of the First World War brought a new challenge to code-breakers. Perhaps the greatest threat was the German Enigma machine and its far more complex big brother, the Lorenz machine. Not that this seemed to bother the British government, who were aware Polish intelligence had managed to `break' an Enigma during its testing with the German army. It did, however, bother Admiral Sir Hugh Sinclair, head of the Secret Intelligence Service (SIS/MI6) and all cryptanalysts who realised that the Polish Enigma was only `broken' until the Germans changed the machine's rotor settings, which at the time they rarely did. With some prescience, Admiral Sinclair decided to set up a joint physical base for SIS and the Government Code and Cipher School (GC&CS), settling on Bletchley Park as their new home.

Bletchley park and big science: industrialising the secret war, 1939-1945

ABSTRACT During the Second World War, Bletchley Park, the headquarters of the Government Code and Cypher School, was the epicentre of a vast scientific enterprise which succeeded in reading enciphered Axis wireless traffic on an industrialised scale. Typically, this important intelligence agency has been depicted as a collegiate organisation with a clear Senior Common Room culture. This article argues that Bletchley Park is better understood as major mechanised, military orientated scientific enterprise with vast numbers of employees, a considerable budget and was subject to careful and professionally managed wartime media control which extended for many years into the post-war period. Each of these facets respectively represents each of the five ‘M’s of ‘Big Science’. As such, the agency can in fact, be viewed and understood as an example of quasi-Big Science.

The secret life of Ian Fleming: spies, lies and social ties

ABSTRACT This article explores the fascinating interactions and experiences of James Bond creator, Ian Fleming, with the real world of intelligence. It has long been known that Fleming worked in Naval Intelligence during the Second World War. However, accounts of his time there tend to portray him as a lowly and slightly eccentric administrator. Drawing on newly discovered archival materials, plus memoirs and histories, it is argued here that Fleming was a respected and influential figure in the great game of espionage for some three decades. During the war, he was a central cog in the machinery of naval intelligence, planning operations, working with partners in American intelligence and liaising with secret Whitehall departments, including the Government Code and Cypher School at Bletchley Park. Before and after the war, he was involved in a range of intelligence networks, often using journalistic cover to hide his clandestine connections. Throughout his life, his social circle was a ‘who’s who’ of spies and saboteurs, including CIA Director Allen Dulles. In short, he straddled the state-private divide. Taken together, these dealings with real intelligence paved the way for and gave veracity to his fiction, which continues to shape public perceptions of intelligence to this day.

Bletchley Park and the Development of the Rockex Cipher Systems: Building a Technocratic Culture, 1941–1945

In 1943 Britain’s security experts began to investigate the development of new cipher machine technologies. This resulted in the creation of the initial projects to construct the Rockex family of cipher systems. The development of the systems marked a major step in the building of a technocratic culture within Britain’s primary wartime cryptanalysis agency, the Government Code and Cypher School housed at Bletchley Park. This article explores the evolution of Bletchley Park’s wartime technocratic culture and utilizes the Rockex project as a case study; moreover it establishes the importance of the project as a catalyst of further institutional cultural change.

Mr. Twinn’s bombes

ABSTRACTThis article discusses the history and design of the special versions of the bombe key-finding machines used by Britain’s Government Code & Cypher School (GC&CS) during World War II to attack the Enigma traffic of the Abwehr (the German military intelligence service). These special bombes were based on the design of their more numerous counterparts used against the traffic of the German armed services, but differed from them in important ways that highlight the adaptability of the British bombe design, and the power and flexibility of the diagonal board. Also discussed are the changes in the Abwehr indicating system that drove the development of these machines, the ingenious ways in which they were used, and some related developments involving the bombes used by the U.S. Navy’s cryptanalytic unit (OP-20-G).

Securing significant patterns: The enigma of forma

The historical case described in this paper, which is based upon a re-interpretation and re-presentation of a vast amount of extant scholarship, centers around the use of the Enigma machine by German armed forces during the Second World War to secure significant patterns and the related work of the Government Code and Cypher School to decode such communicative patterns. Through a fresh examination of this case and the ‘information technologies’ used within intelligence work of the day we achieve a number of things. First, we explore the enigmatic nature of what we term forma – the physical aspect of a seme or sign. We use the case to help illustrate the inherent relationship between the use of forma for mundane purposes of communication and the use of forma to remain mysterious; to mask communicative and performative action. Second, in unpacking the nature of formative action the case material helps re-establish the system in information system. It helps re-conceptualize and broaden the nature of information technology and illustrate more clearly the differences but also the connections between information systems and systems of such technology. Finally, the case enables us to position both IT systems (data systems) and information systems within the wider patterning of significance. This allows us to resurrect the importance of communication and control for the proper conceptualization of situated information systems and their supporting technologies.

Enigma Wiring Data: Interpreting Allied Conventions from World War II

This article explores conventions used by the Government Code and Cypher School (GC&CS) in Britain and the U.S. Navy's OP-20-G in the United States to describe and correct Enigma wiring data recovered cryptanalytically during World War II. Examples are presented and analyzed using wiring information for several machines attacked by the ISK (Intelligence Services–Knox) section of GC&CS and by Unit 387 (the cryptanalytic unit of the United States Coast Guard, absorbed into the U.S. Navy's OP-20-G during the war).

Classic Project: The Enigma Machine

BLETCHLEY PARK'S role in the defeat of the Axis Powers in the Second World War has become legendary. This is where a team of cryptanalysts of the Government Code and Cypher School worked on the Enigma machine code as well the Lorenz ciphers (and some 150 other diplomatic cryptosystems). But it is the decoding of enemy Enigma communications generated by a primitive-looking machine, resembling a manual typewriter with rotating code wheels, and its link with Alan Turing, that keeps Bletchley in the public imagination to this day.

How I learned to stop worrying and love the Bombe: Machine Research and Development and Bletchley Park

The Bombe machine was a key device in the cryptanalysis of the ciphers created by the machine system widely employed by the Axis powers during the Second World War – Enigma. The Bombe machine was initially designed in Britain by scientists in primary cryptanalysis agency, the Government Code and Cypher School at Bletchley Park. The machines were then mass produced by the British Tabulating Machine Company in Britain, and by the National Cash Register Company in the United States of America. The design, development and mass production of the machine was a fraught process dependent on support from scientists and bureaucrats within the agency, but more importantly the agency was only moved to mechanise, and subsequently professionalise, this key function in its operations when met with a series of major crises. The result was an unplanned ad hoc process of designing, building and operating the machines. This was representative of the wider process of mechanisation within Bletchley Park, one of the most important and renowned technological centres to emerge in Britain during the Second World War.

The Making of Bletchley Park and Signals Intelligence 1939–42

The article argues that signals intelligence was an organizational accomplishment in the sense of requiring a) the establishment of an independent organization and b) that this organization combine cryptanalysis with intelligence analysis, traffic analysis and interception. This was not pre-ordained but the outcome of specific conflicts and decisions at Bletchley Park during the first three years of the Second World War which transformed the Government Code and Cypher School from a cryptanalytical bureau to a fully-fledged signals intelligence agency. Detailed archival evidence is presented in support of this claim.

A note on diplomatic intercepts in England during World War II

In February 1942, the diplomatic section of the Government Code and Cypher School (GC and CS) was transferred from Bletchley Park in Buckinghamshire to an office building in Berkeley Street in Lond...

Information Management of British Military Intelligence: The Work of the Documentalists, 1909–1945

After describing briefly the activities of information officers in the early decades of British security services MI5 and the Secret Intelligence Service (SIS, otherwise known as MI6), the work of these documentalists is thereafter explored in the wider context of the information manager in the knowledge organization. Early in the twentieth century, MI5 created its Registry to ensure the efficient use of the information it gathered on suspect aliens. Its equivalent in SIS, housed in Room 40 Admiralty Old Building, was concerned with signals intercepted first on cables and later transmitted by wireless. The Second World War saw similar operations, including those of the London Reception Centre (LRC) and of the Government Code & Cypher School (GCCS) in Bletchley Park. This paper describes briefly the means by which the intelligence could be put to efficient use to provide effective and efficient support to their customers, the “spycatchers,” “the watch,” and the researchers, or “back room.”

Report on Speech Secrecy System DELILAH, a Technical Description Compiled by A. M. Turing and Lieutenant D. Bayley REME, 1945–1946

Click to increase image sizeClick to decrease image size Acknowledgments Government Code and Cypher School: Cryptographic Studies, HW 25/36. This report was released to the British National Archives in 2009 but has never before been published. It was retyped by Craig Bauer to appear here. The accompanying figures were too large to be reasonably included with the report here. A short list of abbreviations, provided by John Harper, has been added just prior to the appendices.

Bletchley Park and the RAF Y Service: Some Recollections

The RAF Y Service and the German Air Section at Bletchley Park collaborated in producing a great deal of intelligence about GAF (German Air Force) operations in World War II. However, two errors in pre-war planning reduced this output. The first error was the decision that the Government Code and Cypher School (GC&CS) should be responsible solely for cryptography, the interpretation of Sigint to be the task of the Intelligence recipients. The second was the general assumption that the information obtainable from intercepting the low-grade codes and plain language used in the control of Air operations would only be of intelligence interest while the operations were in progress. After-the-event study of these communications by the German Air Section produced unique information needed by the RAF Commands. The Air Ministry took an unduly long time to agree that this information should be provided to them.

The 1942 Reorganization of the Government Code and Cypher School

This paper analyses the organization of the Government Code and Cypher School (GC & CS) at Bletchley Park during the Second World War. The complexities and peculiarities of the organization are overviewed and a periodization provided. The main focus is on the pivotal 1942 reorganization, which is explained in terms of the changing scale of GC & CS following the successful attack on the Enigma machine cipher, and in terms of organizational politics. The more minor 1944 reorganization is also described.

Captured Kriegsmarine Enigma Documents at Bletchley Park

This paper lists Enigma-related Kriegsmarine documents captured by the British during the Second World War and describes the formation and functions of Naval Section VI, which dealt with captured documents in the British Government Code and Cypher School.

An indexing needle in an intelligence haystack

Experiences in researching the documentation of the intelligence (codename Ultra) produced by breaking Enigma at Government Code & Cypher School, Bletchley Park, 1939—45, are described. The major problems are identified and shown to lie in the obscurity of the associated processes, disguised as they were within general bureaucratic arrangements. This resulted in invisibility in both National Archives documents and publications in the field of military intelligence. This invisibility, along with difficulties in locating surviving veterans capable of illuminating such historical material as there is, demands detective work, serendipity and luck in addition to the normal skills of historical method in telling the story.

William Friedman's Bletchley park diary: A different view

‘William Friedman's Bletchley Park Diary’ (INS 20/4 (2005) pp. 654–69) stated that Friedman, with Col. Alfred McCormack and Lt.-Col. Telford Taylor (US Army Special Branch), visited Bletchley Park in mid-1943 to negotiate with the British Government Code and Cypher School on how the Travis–Strong Agreement of May 1943 on Sigint cooperation should be implemented. This article shows that they had no substantive negotiating powers, and that they were essentially on a fact-finding mission.

MI1(b) and the origins of British diplomatic cryptanalysis

The War Office's First World War cryptanalytic bureau MI1(b) has been severely overshadowed by its more glamorous equivalent in the Admiralty, ‘Room 40’. In particular its diplomatic decryption work has gone completely unnoticed; yet this was its main activity, and it contributed more than did Room 40 to their common successor, the Government Code and Cypher School (GC&CS). This article, drawing on the past decade's releases of GC&CS archives, traces the development of MI1(b)'s diplomatic work, disentangles its achievements from those of its better-known naval colleague, describes how the two organizations were merged to become GC&CS, and suggests why MI1(b)'s achievements were so quickly forgotten.

The Poles Reveal their Secrets: Alastair Denniston's Account of the July 1939 Meeting at Pyry

Sets out, with comments, an account by A. G. Denniston (the operational head of the British Government Code and Cypher School in 1939) of the meeting near Pyry, Poland, in July 1939, when Polish cryptanalysts revealed how they broke Enigma, and a letter by Dillwyn Knox on the meeting's outcome.