The Bletchley Park Codebreakers (67 page)
Read The Bletchley Park Codebreakers Online
Authors: Michael Smith
WEHRMACHT
ENIGMA INDICATING SYSTEMS, EXCEPT THE
KRIEGSMARINE’S KENNGRUPPENBUCH
SYSTEM
Page
1
Heer
and
Luftwaffe
indicating system from 1 May 1940:
Schlüsselanleitung zür Chiffriermaschine
Enigma (H. Dv. g. 14) of 13 January 1940, as amended.
Page
2
typed them once only: ibid., para. 11; Gilbert Bloch and Ralph Erskine, ‘Enigma: The Dropping of the Double Encipherment’,
Cryptologia
, 10 (1986), 134.
Page
3
Heer
and
Luftwaffe
indicating system from 15 September 1938:
Schlüsselanleitung zür Chiffriermaschine
Enigma (H. Dv. g. 14) of 8 June 1937, as amended.
Page
4
Heer
and
Luftwaffe
indicating system before 15 September 1938:
Schlüsselanleitung zür Chiffriermaschine
Enigma (H. Dv. g. 14) of 8 June 1937.
Page
5
naval indicating system used before 1 May 1937: ‘Mathematical theory of ENIGMA machine by A. M. Turing’, 129 (PRO HW 25/3).
Page
6
may have been chosen from a list: ibid.
Page
7
the
Kriegsmarine
employed the pre-1 May 1937 system: on the throwon indicating system for
Süd
and other ciphers, see
Kenngruppenverfahren Süd Januar 1944
(M. Dv. Nr. 608) (PRO ADM 223/331); Ralph Erskine and Philip Marks, ‘Naval Enigma: Seahorse and other
Kriegsmarine
cipher blunders’,
Cryptologia
, 28 (2004), 211.
KENNGRUPPENBUCH
INDICATOR SYSTEM
Page
1
the
Kenngruppenbuch
(recognition group book) system: Der
Schlüssel M Verfahren M Allgemein
(M. Dv. Nr. 32/1 – August 1940 edition), paras 46–76;
Kenngruppenbuch
(M. Dv. Nr. 98).
Page
2
‘it takes a considerable time’: SR 323, 6 January 1943 (PRO WO 208/4201).
Page
1
Cillies: for a full discussion of cillies, see ‘Cryptanalytic Report on
the Yellow Machine’, 71–4 (NACP HCC Box 1009, Nr. 3175). Some of the examples in this Appendix are based on that Report. Gordon Welchman later acknowledged that his account of the cillies (called ‘Sillies’ by him) in
The Hut Six Story: Breaking the Enigma Codes
(Allen Lane, London, 1982), pp. 99–101, was wrong: Gordon Welchman, ‘From Polish Bomba to British Bombe: the Birth of Ultra’,
Intelligence and National Security
, 1(1) (1986), 71.
Page
2
test the first message part for a cilli: readers who would like to test these examples may download excellent
Wehrmacht
Enigma simulators (which have been fully tested against real versions) from the following sites –
http://cryptocellar.org/ look for ‘CSG Machine Simulators for Windows.
http://www.hut-six.co.uk
Page
3
fully random lists: ‘Changes in encyphering with machine keys’, 27 August 1944 (PRO HW 25/13 Nr. 9879/44).
Page
1
divisible by three: except in the Nan code. Instead, no group contained zeros.
| Abwehr | the Wehrmacht’s intelligence service. |
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| additive | a series of random numbers (occasionally letters) added to a code to encipher it. |
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| angoo-ki taipu a | see Red (Japanese). |
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| angoo-ki taipu b | see Purple. |
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| ATS | (Women’s) Auxiliary Territorial Service; also applied to members of that Service. |
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| Banburismus | a Bayesian probability process using specially prepared punched sheets to identify the right-hand and middle rotors in the Enigma M3 machine by relating distances in message keys. |
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| basic setting | see Grundstellung. |
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| B-Dienst | ( Beobachtungsdienst – observation service). Cover name for the Kriegsmarine’s codebreaking section. |
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| bigram tables | (naval Enigma) sets of tables which substituted pairs of letters (e.g. AA=DF, AB=UA, and so on); used to encode the indicator groups in the Kenngruppenbuch indicating system for naval Enigma. |
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| BJ | (blue jacket) decrypt being circulated to a government department (derived from the distinctive blue file cover). |
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| blist | Bannister list – a register of Enigma messages, listing important components such as call signs, length of messages etc. (see example in Appendix IV). Designed to help the detection of cillies and the identification of messages with cribs. |
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| bombe | ultra-fast machine for recovering Enigma daily keys by testing a crib and its implications, at all possible rotor orders and initial settings. |
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| BP | Bletchley Park. |
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| BRUSA | British United States Agreement of May 1943 (also known as the Travis-Strong Agreement), between the United States War Department and GC&CS on attacking the military codes and ciphers of the Axis powers. |
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| ‘C’ | the ‘Chief’ or head of the British Secret Intelligence Service. |
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| cilli | a German mistake, found by Dilly Knox, in using the rotor finishing positions in one part of a multi-part Enigma message as the Grund of the next part. Derived from CIL, the Grund of the message in which the mistake was first discovered. |
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| cipher | a cryptographic system in which letters or numbers represent plain-text units (generally single letters) in accordance with agreed rules. |
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| cipher indicator group (naval) | group indicating the cipher for a message (and therefore the key-lists to look up when enciphering or deciphering it). |
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| cipher text | text produced by a cipher. |
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| closure | the linking of the same letter in a chain in an Enigma menu (e.g., ACHIA) that returns to its starting point. |
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| code | a cryptographic system, generally set out in a codebook, in which groups of letters or numbers represent plain-text units of varying lengths. |
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| Coral | the US Navy cover name for a cipher machine (JNA-20) used by Japanese naval attachés. Like Purple (q.v.), it incorporated telephone selector switches, not rotors. |
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| counter Enigma | (German Zählwerk) the Abwehr three-rotor Enigma machine using rotors with 11, 15 and 17 notches, but without a plugboard. |
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| crib | probable plain-text, which for Enigma was generally derived from a re-enciphered message (whether using Enigma or a manual cipher) or standard message (e.g., ‘nothing to report’). |
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| CSS | C hief, Secret Intelligence Service (‘C’). |
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| depth | the correct alignment of two or more cipher texts that have been enciphered by the same key. |
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| DF | direction finding – locating the position of a transmission by plotting two or more bearing lines. |
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| diagonal board | a circuit in the bombes that eliminated a considerable number of superfluous stops. By enabling the effective use of menus that did not consist entirely of closures, it greatly increased the power and flexibility of the bombes. |
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| discriminant | (Enigma - German Kenngruppe) a group showing the cipher being used. |
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| doubly encipher | to encipher something (e.g. text or a message key) twice (cf. Offizier ). |
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| dud | a ciphered message which cannot be deciphered because of a faulty message setting or discriminant. |
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| Duenna | a US Navy machine which used long cribs to find the wiring of the rewirable Enigma reflector, UKD. |
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| enciphered code | code enciphered by a cipher system (generally a series of random figures known as an additive). The ‘additive’ figures are lined up under the encoded message, and added to the code digits using non-carrying arithmetic (5 plus 7 producing 2 rather than 12) to produce the enciphered message. |
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| false stop | a position at which a bombe stopped, but giving an impossible result for the Stecker (e.g., B steckered to X, but also to Y). |
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| FECB | Far East Combined Bureau. British intelligence organization, covering all fields of intelligence, including special intelligence – interception, breaking and analysis of foreign encoded radio messages. Based in Hong Kong from 1934 and in Singapore from September 1939 until January 1942. |
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| female | (Enigma) a letter in the second group of a doubly enciphered Enigma message key, which repeats a letter in the corresponding position in the first group (e.g. AFO CFK). |
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| Fish | GC&CS cover name for traffic enciphered on the Sturgeon or Tunny teleprinter cipher machines. |
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| Freebornery | the punched card section under Frederic Freeborn. |
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| FRUMEL | Fleet Radio Unit (Melbourne). US Navy wartime intercept and codebreaking organization based in Melbourne, Australia. |
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| FRUPAC | Fleet Radio Unit (Pacific). US Navy intercept and codebreaking organization in Hawaii. |
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| garble | a distorted part of a message. |
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| GC&CS | the Government Code and Cypher School. |
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| Green | (later renamed Greenshank) an intractable Enigma cipher. |
| Grund | short for Grundstellung (q.v.). |
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| Grundstellung | (Enigma) the basic initial position of the rotors at which the message key is enciphered or deciphered. |
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| Hagelin C-38 | a mechanical cipher machine invented by Boris Hagelin, and used by the Italian navy; very similar to the Hagelin M 209 adopted by the US Army. |
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| Heer | the German Army in the Second World War |
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| Herivel tip | a method used to deduce the daily Ringstellungen , especially in Luftwaffe Enigma ciphers, from a series of Grundstellungen at the start of a cipher period. Named after John Herivel, who first realized that some operators would use the ring settings as Grundstellungen in this way. |
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| Herivelismus | the application of the Herivel tip. |
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| Hut 3 | the GC&CS section responsible for translating and analysing Enigma decrypts received from Hut 6, together with related intelligence, and for distributing the resulting intelligence. |
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| Hut 4 | the CC&CS section responsible for translating, analysing Enigma decrypts received from Hut 8, and for all naval cryptanalysis, except Enigma, and for sending the translated Enigma and other naval decrypts to the Admiralty. |
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| Hut 6 | the GC&CS section responsible for solving Heer, Luftwaffe and Railway Enigma ciphers. |
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| Hut 8 | the GC&CS section responsible for solving Kriegsmarine Enigma ciphers. |
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| indicator | a group of letters or symbols showing the cipher system being used. |
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| indicator groups | (naval Enigma) two groups setting out the cipher recognition group and procedure indicator group (from which the message key was derived). |
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| ISK | Illicit Services, Knox (also Intelligence Services, Knox). |
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| ISOS | Illicit Services, Oliver Strachey (also Intelligence Services, Oliver Strachey). |
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| Jeffreys sheets | a catalogue of the effect of any two rotors and the reflector in Enigma. Not to be confused with Zygalski sheets (q.v.). |
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| JIC | Joint Intelligence Committee. |
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| JN | Japanese naval. Used with a number to denote a Japanese naval code or cipher, such as JN-25 (the principal naval code). |
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| JNA | Japanese naval attaché. |
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| JNA-20 | See Coral |
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| JN-25 | the principal Japanese Navy general operational code, a superenciphered code introduced in June 1939 and used in numerous versions throughout the war. The JN-25 code and cipher additive books were allocated different letters and numbers by the Allies, as in JN-25B7, where ‘B’ denoted the ‘Baker’ codebook being used, and the final figure (‘7’ here), the relevant additive book. |
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| kana | Japanese syllable depicting a phonetic sound. |
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| kanji | the familiar Japanese ideographs on which the written language is based. |
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| Kenngruppenbuch | (naval Enigma) recognition group book; a book containing trigrams, used with the main naval Enigma indicating system (see Appendix III). |
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| key | a) as respects Enigma, an Enigma cipher, such as Red, Phoenix, etc.; b) as respects Enigma, the machine set-up for a day or period, consisting of the Walzenlage , Ringstellungen and Stecker (also the Grundstellung for Kriegsmarine Enigma ciphers); c) generally, a series of numbers or symbols used to encipher text. |