British Intelligence

Cryptology gained support after WWII, leading to rapid expansion of intelligence agencies, exemplified by the increased presence of communications intelligence in British policy.

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A Move to Mass Production

The sheer amount of incoming messages during World War II forced Bletchley Park to transform the process of intelligence gathering from small scale hand decryption to an industrialized process.

"Enigma marked the move from book-based encryption systems to electro-mechanical systems... and that was scalable to an industrial level"
-Tony (last name unavailable due to security), official GCHQ Historian

Mouse over the blue circles to view compartmentalization of Bletchley.

Bletchley Park operated like a factory,  cryptographic tasks were compartmentalized, handled by specialized groups and machinery (see map).

Bombe in use

"The heavy used of electro-mechanical devices, the Bombes, to break the Enigma ciphers added to the industrialized nature of codebreaking at Bletchley, a complete contrast to the more leisurely, more individualistic pre-war codebreaking" - Michael Smith, author of The Secrets of Station X

"The techniques developed in relation to Ultra were then used throughout the Cold War. I mean, they're being used today" - David O'Keefe, military historian

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Role in Policy

During the Cold War, GC&CS was renamed Government Communications Headquarters (GCHQ), signifying its expansion into a powerful and active intelligence organization.

"Many of GCHQ's activities such as large-scale radio interception, high-speed analytic machinery and massive communications networks had no pre-war parallels" - MI6

GCHQ Activity

"It is all but impossible to draw a distinction between GCHQ's work in Germany and her growing work in the Soviet Union in the 1940s" - Richard Aldrich, Professor of International Security

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Ultra

"The secret British program to monitor and decipher Germany's Enigma signals"
- Sir Lawrence David Freedman, Professor of War Studies, King's College London

Enigma

“Three rotors, side by side, created an electrical maze. As they turned, they changed the maze - and thereby the encipherment. The result was a rather secure cipher”
- Dr. David Kahn, leading historian

Bletchley Park

“Bletchley Park was concentrated on deciphering, translating, evaluating and distributing the vast amount of information...transmitted by the Germans after they had been rendered 'secure' by encipherment on the famous Enigma machine”
- Ronald Lewin, British military historian

GCHQ

"After the war, it took over from the Government Code and Cipher School the function of receiving and decoding intercepted wireless traffic from listening stations scattered throughout the United Kingdom and from several dozen overseas"
- Lord Jonathan Sumption, British judge, author and medieval historian

Double Cross System

"For the duration of the war, brilliantly orchestrated false reports sent back to Germany by Masterman's tame agents would lead the German high command into one blunder after another at the most crucial junctures - ensuring the success of the Allied landing at Normandy, helping to turn the tide in the war against U-boats in the Atlantic, even tricking the Germans into firing most of their V-2 rockets short of central London"
- Stephen Budiansky, former national security correspondent, foreign editor, and deputy editor of U.S. News & World Report

Communications Intelligence (COMINT)

"COMINT is technical and intelligence information derived from foreign communications by other than the intended recipients"
- Department of Defense Directive, 2010

Signals Intelligence (SIGINT)

"Intelligence obtained through the interception of transmission signals"
- Merriam Webster Dictionary

Public Key Encryption

“A standard analogy for public-key cryptography is given as follows. Suppose that Bob has a wall safe with a secret combination lock known only to him and the safe is left open and made available to passers-by. Then anyone, including Alice, can put messages in the safe and lock it. However, only Bob can retrieve the message, since even Alice, who left a message in the box, has a way of retrieving the message.”
- Richard A. Mollin, author and professor