Hosted and supported by the "Big Oxford Computer Co Ltd", BOCC

What's New??
2 September 2004, More about the attack on Lorenz
8 June 2004, the Colossus Mk 2 Rebuild story
6 June 2004, New DVD of Colossus Mk 2 rebuild breaking a Lorenz cipher go "buy on line"

Codes and Ciphers
in the
Second World War

The history, science and engineering of cryptanalysis in World War II

created by Tony Sale

Between 1939 and 1945, the most advanced and creative forms of mathematical and technological knowledge were combined to master German communications.

British cryptanalysts, Alan Turing at the forefront, changed the course of the Second World War and created the foundation for the modern computer.

In 1991 the Bletchley Park, the wartime home of Allied code breaking, was saved from destruction by Tony Sale and some colleagues. They transformed it into a museum devoted to the recognition and reconstruction of this crucial aspect of world history, which had remained completely secret until the early 1970s.

Buy on line!!

Now available:
the June 2004 Colossus Mk2 rebuild breaking a Lorenz cipher
the first stage of the Colossus Rebuild
Tony Sale's DVDs on Early Bletchley Park and
a CD image of this web site.

"Anoraks Corner"
Break Enigma!!!
and Lorenz too!!!

Break Lorenz!!
Break real Lorenz enciphered messages using Colossus, WARNING! this may overheat your brain!!
Are you up to breaking
real Enigma messages?

Status Log Scenario 6 now up!
ENIGMA

Tony Sale's reconstruction of Enigma decipherment for the film Enigma

This film is based on Robert Harris's novel Enigma. Although essentially fiction, it contains detailed sequences of Enigma codebreaking which have been scrupulously reconstructed by Tony Sale. Go to these pages by Tony Sale for full details.

An interactive exploration of Bletchley Park and World War II code breaking from 1938 to the present day.
Status Log . Not perfect but ready by Friday.

The Enigma

Follow a sequence of pages explaining how the Enigma worked.
Keyboard of an Enigma

The Lorenz cipher and the Colossus

A sequence of pages explains the Lorenz cipher and how it was broken by the Colossus

Colossus Mk 1 rebuild slowly evolves into Colossus Mk2 by 2004

See how the dedicated Colossus Rebuild Team achieved this.

The first stage of the rebuilt Colossus has been working since 6 June 1996.

LEFT: (in wheelchair) Tommy Flowers, designer and engineer in 1943.
CENTRE: HRH The Duke of Kent, patron, switching on.
RIGHT: Tony Sale, rebuilder and curator.

Bletchley Park
and its Museums:

The original Mansion and many Huts in the surrounding park are largely unchanged since 1945.

Open a MAP of the Park.

Follow a Virtual Tour of the Park.
Five pages with fifty small pictures


Bletchley Park Mansion

Lectures by Tony Sale

Lecture Notes on the Enigma and the Bombe, on Naval Enigma and on the Colossus are available.

Continue to the Lecture Index page.



Original World War II Documents

  • Fish Notes by Captain Walter Fried describing in great detail the work of the Newmanry and Testery in Bletchley Park on breaking the Fish codes, Tunny (Lorenz) and attempting to break Sturgeon (Siemans). Continue to Fish Notes.

  • Annex to Fish Note #F 071 giving a detailed account of breaking Lorenz from Delta D and lists the Colossus runs used. Continue to Delta D and Colossus runs.

  • Critical Observations on German Traffic Analysis in Sixta

  • Part of the History of Sixta written by Robert G. Nunn Jr. at the end of the war. Continue to Observations on Sixta.

  • The History of the American 6813th Detachment

  • Written by members of the American 6813th Signal Security Detachment seconded to Bletchley Park from August 1943. Continue to Introduction to the 6813th History.

  • The Report on the British Bombe

  • Written by members of the United States 6812th Division who were seconded to the Bombe outstation at Eastcote in North London in 1944. Continue to Introduction to the US 6812 Bombe Report.

  • Tentative List of Enigma and Other Machine Usages

    • A report written in Bletchley Park in 1945. Continue to Usages Index.

  • The German manual for the naval use of the Enigma (1940)

    • This document, the Enigma General Procedure, was captured and translated by the British. It can now be read on this site. Continue to the Index page to the Enigma General Procedure.

  • The German manual for the doubly enciphered Naval Enigma messages (1940)

    • This is the protocol for the offizierte messages which were doubly enciphered for officer's eyes only. It was also captured and translated by the British. Continue to the Index page to the Offizier and Staff Procedure.

  • The Bletchley Park Cryptographic Dictionary (1944)

    • This document listed and defined the hundreds of specialist concepts and activities at Bletchley Park. Continue to the Introduction to the Dictionary.

  • The Newmanry History (1945)

    • This document, kept secret until 2000, is the most crucial part of a longer General Report on Tunny. It gives the complete story of how the Lorenz cipher was broken, from the amazing breakthrough of 30 August 1941 up to the extremely sophisticated programming of the Colossus. Continue to The Newmanry History.

  • The Special Report on Fish (1944)

    • This document gives a complementary account of the breaking of the Lorenz ciphers through the use of Colossus, as reported at the time by an American cryptanalyst attached to Bletchley Park. Continue to The Special Report on Fish.




    You may also wish to visit:

    Turing Bombe Reconstruction Project

    Alan Turing Home Page

    Frode Weierud's Cryptology pages

    David Hamer's Enigma pages

    Bletchley Park Trust

    Willard Thompson's pages on Bletchley Park


    This page is created by Tony Sale (tsale@qufaro.demon.co.uk) the original founder and curator of the Bletchley Park Museum.
    Original Web design by Andrew Hodges, biographer of Alan Turing.