|
|
| Line 1: |
Line 1: |
| [[Image:Lorenz-SZ42-2.jpg|right|280px|thumbnail|The Lorenz SZ42 machine with its covers removed.]]
| | I'm Georgina (22) from Kinsbourne Green, Great Britain. <br>I'm learning Portuguese literature at a local university and I'm just about to graduate.<br>I have a part time job in a the office.<br><br>My page [http://www.online-cna-classes.org/ certified nursing assistant classes] |
| The '''Lorenz SZ40''', '''SZ42A''' and '''SZ42B''' were German [[Rotor machine|rotor]] [[stream cipher]] machines used by the [[German Army (1935–1945)|German Army]] during [[World War II]]. They were developed by C. Lorenz AG in [[Berlin]] and the model name ''SZ'' was derived from ''Schlüsselzusatz'', meaning ''cipher attachment''. The instruments implemented a [[Gilbert Vernam#The Vernam cipher|Vernam]] [[stream cipher]].
| |
| | |
| British [[cryptographer]]s, who referred to encrypted German [[Electrical telegraph|teleprinter]] traffic as [[Fish (cryptography)|''Fish'']], dubbed the machine and its traffic '''''Tunny'''''.<ref>{{Harvnb|Hinsley|1993|p=141}}</ref>
| |
| | |
| The SZ machines were in-line attachments to standard Lorenz [[teleprinter]]s. An experimental link using SZ40 machines was started in June 1941. The enhanced SZ42 machines were brought into substantial use from mid-1942 onwards for high-level communications between the [[Oberkommando der Wehrmacht|German High Command]] in Berlin, and Army Commands throughout occupied Europe.<ref>{{Harvnb|Hinsley|1993|p=142}}</ref> The more advanced SZ42A came into routine use in February 1943 and the SZ42B in June 1944.<ref>{{Harvnb|Copeland|2006|pp=38, 39}}</ref>
| |
| | |
| [[Wireless telegraphy]] (WT) rather than land-line circuits was used for this traffic.<ref name = "GRoT11A4" >{{Harvnb|Good|Michie|Timms|1945|p=4}} of ''German Tunny''</ref> These non-[[Morse code|Morse]] (NoMo) messages were picked up by Britain's [[Y-stations]] at [[Knockholt]] and [[Denmark Hill]] and sent to [[Government Communications Headquarters#Government Code and Cypher School|Government Code and Cypher School]] at [[Bletchley Park]] (BP). Some were deciphered using hand methods before the process was partially automated, first with [[Heath Robinson (codebreaking machine)|Robinson machines]] and then with the [[Colossus computer]]s.<ref>{{Harvnb|Good|1993|pp=160–165}}</ref> The deciphered messages made an important contribution to ''[[Ultra]]'' [[military intelligence]].
| |
| | |
| ==The Vernam cipher==
| |
| {{main|Gilbert Vernam}}
| |
| [[Gilbert Vernam]] was an [[AT&T Corporation|AT&T]] [[Bell Labs]] research engineer who, in 1917, invented a cipher system that used the [[Boolean algebra (logic)|Boolean]] [[Exclusive or|"exclusive or" (XOR)]] function, symbolized by ⊕.<ref>{{Harvnb|Klein|p=2}}</ref> This is represented by the following "[[truth table]]", where 1 represents "true" and 0 represents "false".
| |
| | |
| {| class="wikitable" style="margin: 1em auto 1em auto"
| |
| |- bgcolor="#ddeeff" align="center"
| |
| |colspan=2|'''INPUT''' || '''OUTPUT'''
| |
| |- bgcolor="#ddeeff" align="center"
| |
| | '''''A''''' || '''''B''''' || '''''A'' ⊕''B'''''
| |
| |- bgcolor="#ddffdd" align="center"
| |
| |'''0''' || '''0''' || '''0'''
| |
| |- bgcolor="#ddffdd" align="center"
| |
| |'''0''' || '''1''' || '''1'''
| |
| |- bgcolor="#ddffdd" align="center"
| |
| |'''1''' || '''0''' || '''1'''
| |
| |- bgcolor="#ddffdd" align="center"
| |
| |'''1''' || '''1''' || '''0'''
| |
| |}
| |
| Other names for this function are: Not equal (NEQ), [[Modular arithmetic|modulo]] 2 addition (without 'carry') and modulo 2 subtraction (without 'borrow').
| |
| | |
| Vernam's cipher is a [[Symmetric-key algorithm]], i.e. the same [[Key (cryptography)|key]] is used both to encipher [[plaintext]] to produce the [[ciphertext]] and to decipher ciphertext to yield the original plaintext:
| |
| | |
| ::::Plaintext ⊕ Key = Ciphertext
| |
| | |
| and:
| |
| | |
| ::::Ciphertext ⊕ Key = Plaintext
| |
| | |
| This produces the essential reciprocity that allows the same machine with the same settings to be used for both enciphering and deciphering.
| |
| | |
| Vernam's idea was to use conventional telegraphy practice with a paper tape of the plaintext combined with a paper tape of the key. Each key tape would have been unique (a one-time tape), but generating and distributing such tapes presented considerable practical difficulties. In the 1920s four men in different countries invented rotor cipher machines to produce a key stream to act instead of a tape.<ref>{{Harvnb|Klein|p=3}}</ref> The 1940 Lorenz SZ40/42 was one of these.<ref name = "GRoT11B10">{{Harvnb|Good|Michie|Timms|1945|p=10}} of ''German Tunny''</ref>
| |
| | |
| ==Structure==
| |
| The logical functioning of the Tunny system was worked out well before the Bletchley Park cryptanalysts saw one of the machines—which only happened in 1945, shortly before the allied victory in Europe.<ref name=Sale>{{ Citation | last = Sale | first = Tony | author-link = Anthony Sale | title = The Lorenz Cipher and how Bletchley Park broke it | url = http://www.codesandciphers.org.uk/lorenz/fish.htm | accessdate = 21 October 2010 }}</ref>
| |
| [[Image:SZ42-6-wheels-lightened.jpg|right|340px|thumbnail|The Lorenz SZ machines had 12 wheels each with a different number of cams (or "pins").
| |
| {|class="wikitable" | border=1 | style="margin: 1em auto 1em auto"
| |
| |-
| |
| ! Wheel number
| |
| |1||2||3||4||5||6||7||8||9||10||11||12
| |
| |-
| |
| ! BP wheel name<ref name = "GRoT11B6">{{Harvnb|Good|Michie|Timms|1945|p=6}} of ''German Tunny''</ref>
| |
| | align="center" | <math>\psi</math><sub>1</sub>
| |
| | align="center" | <math>\psi</math><sub>2</sub>
| |
| | align="center" | <math>\psi</math><sub>3</sub>
| |
| | align="center" | <math>\psi</math><sub>4</sub>
| |
| | align="center" | <math>\psi</math><sub>5</sub>
| |
| | align="center" | <math>\mu</math>37
| |
| | align="center" | <math>\mu</math>61
| |
| | align="center" | <math>\chi</math><sub>1</sub>
| |
| | align="center" | <math>\chi</math><sub>2</sub>
| |
| | align="center" | <math>\chi</math><sub>3</sub>
| |
| | align="center" | <math>\chi</math><sub>4</sub>
| |
| | align="center" | <math>\chi</math><sub>5</sub>
| |
| |-
| |
| ! Number of cams (pins)
| |
| |43||47||51||53||59||37||61||41||31||29||26||23
| |
| |}
| |
| ]]
| |
| The SZ machine served as an in-line attachment to a standard Lorenz teleprinter. It had a metal base {{convert|19|in|abbr=on|cm|0}} × {{convert|15.5|in|abbr=on|cm|0}} and was {{convert|17|in|abbr=on|cm|0}} high.<ref name = "GRoT11B10"/> The teleprinter characters consisted of five data [[bit]]s, encoded in the [[Baudot code#ITA2|International Telegraphy Alphabet No. 2 (ITA2)]]. The enciphering machine generated a [[pseudorandom number generator|pseudorandom]] character-by-character key that was XOR-ed with the input characters to form the output characters.<ref name = "GRoT11B6"/>
| |
| | |
| Each of the five bits (or "impulses") of the key for each character was generated by the relevant wheels in two parts of the machine. The Bletchley Park analysts called these the <math>\chi</math> ("[[Chi (letter)|''chi'']]") wheels, and the <math>\psi</math> ("[[Psi (letter)|''psi'']]") wheels. Each wheel had a series of cams (or "pins") around them. These cams could be set in a raised (active) or lowered (inactive) position. In the raised position they generated a '1', in the lowered position they generated a '0'.
| |
| | |
| The ''chi'' wheels all moved on one position for each character. The ''psi'' wheels also all moved together, but not after each character. Their movement was controlled by the two <math>\mu</math> ("[[Mu (letter)|''mu'']]") or "motor" wheels.<ref name = "GRoT11B7">{{Harvnb|Good|Michie|Timms|1945|p=7}} of ''German Tunny''</ref> The SZ40 <math>\mu</math>61 wheel moved one position with each character, but the <math>\mu</math>37 wheel moved on only when the cam on the <math>\mu</math>61 wheel was in the active position. If the cam on the <math>\mu</math>37 wheel was in the active position, all five ''psi'' wheels then moved.<ref name = "GRoT11B7"/> The SZ42A and SZ42B models had additional complexity to this mechanism, known at Bletchley Park as ''Limitations''.<ref>{{Harvnb|Good|Michie|Timms|1945|p=8}} of ''German Tunny''</ref>
| |
| | |
| The key stream generated by the SZ machines thus had a ''chi'' component and a ''psi'' component that were combined together with the XOR function. Symbolically, the key that was combined with the plaintext for enciphering—or with the ciphertext for deciphering—can be represented as follows.<ref name = "GRoT11B7" />
| |
| | |
| ::::Key = ''Chi''-Key ⊕ ''Psi''-Key
| |
| | |
| The number of cams on each wheel equalled the number of impulses needed to cause them to complete a full rotation. It should be noted that these numbers are all [[Coprime|co-prime]] with each other, giving the longest possible time before the pattern repeated. With a total of 501 cams this equals 2<sup>501</sup> which is approximately 10<sup>151</sup>, an astronomically large number.<ref>{{Harvnb|Churchhouse|2002|p=158}}</ref> However, if the five impulses are considered independently, the numbers are much more manageable. The [[Multiplication|product]] of the rotation period of any pair of ''chi'' wheels gives numbers between 41×31=1271 and 26×23=598.
| |
| | |
| ==Operation==
| |
| Each "Tunny" link had four SZ machines with a transmitting and a receiving teleprinter at each end. For enciphering and deciphering to work, the transmitting and receiving machines had to be set up identically. There were two components to this; setting the patterns of cams on the wheels and rotating the wheels for the start of enciphering a message. The cam settings were changed less frequently before the Summer of 1944. The ''psi'' wheel cams were initially only changed quarterly, but later monthly, the ''chi'' wheels were changed monthly but the motor wheel patterns were changed daily. From 1 August 1944, all wheel patterns were changed daily.<ref name = "GRoT11E14" >{{Harvnb|Good|Michie|Timms|1945|p=14}} of ''German Tunny''</ref>
| |
| | |
| Initially the wheel settings for a message were sent to the receiving end by means of a 12-letter [[Cryptanalysis#Indicator|indicator]] sent un-enciphered, the letters being associated with wheel positions in a book. In October 1942 this was changed to the use of a book of single-use settings in what was known as the QEP book. The last two digits of the QEP book entry were sent for the receiving operator to look up in his copy of the QEP book and set his machine's wheels. Each book contained one hundred or more combinations. Once all the combinations in a QEP book had been used it was replaced by a new one.<ref>{{Harvnb|Copeland|2006|p=45}}</ref> The message settings should never have been re-used, but on occasion they were, providing a "depth", which could be utilised by a cryptanalyst.<ref>{{Harvnb|Churchhouse|2002|p=34}}</ref>
| |
| | |
| As was normal telegraphy practice, messages of any length were keyed into a [[teleprinter]] with a [[Punched tape|paper tape]] perforator. The typical sequence of operations would be that the sending operator would punch up the message, make contact with the receiving operator, use the ''EIN / AUS'' switch on the SZ machine to connect it into the circuit, and then run the tape through the reader.<ref name = "GRoT11B10" /> At the receiving end, the operator would similarly connect his SZ machine into the circuit and the output would be printed up on a continuous sticky tape. Because this was the practice, the plaintext did not contain the characters for "carriage return", "line feed" or the null (blank tape, 00000) character.<ref name = "GRoT11A4" />
| |
| | |
| ==Cryptanalysis==
| |
| {{main|Cryptanalysis of the Lorenz cipher}}
| |
| British cryptographers at [[Bletchley Park]] had deduced the operation of the machine by January 1942 without ever having seen a Lorenz machine, a feat made possible by a mistake made by a German operator.
| |
| | |
| ===Interception===
| |
| Tunny traffic was known by [[Y Service|Y Station]] operators used to listening to [[Morse code]] transmission as "new music". Its interception was originally concentrated at the Foreign Office Y Station operated by the [[Metropolitan Police]] at [[Denmark Hill]] in [[Camberwell]], London. But due to lack of resources at this time (~1941), it was given a low priority. A new Y Station, [[Knockholt]] in [[Kent]], was later constructed specifically to intercept Tunny traffic so that the messages could be efficiently recorded and sent to Bletchley Park.<ref>{{Harvnb|Good|Michie|Timms|1945|p=281}} in ''Knockholt''</ref> The head of Y station, [[Harold Kenworthy]], moved to head up Knockholt. He was later promoted to head the Foreign Office Research and Development Establishment (F.O.R.D.E).
| |
| | |
| ===Code breaking===
| |
| On 30 August 1941, a message of some 4,000 characters was transmitted from [[Athens]] to [[Vienna]]. However, the message was not received correctly at the other end, so (after the recipient sent an unencoded request for retransmission, which let the codebreakers know what was happening) the message was retransmitted with the same key settings (HQIBPEXEZMUG); a forbidden practice. Moreover, the second time the operator made a number of small alterations to the message, such as using abbreviations, making the second message somewhat shorter. From these two related ciphertexts, known to cryptanalysts as a [[Cryptanalysis#Depth|depth]], the veteran cryptanalyst [[John Tiltman|Brigadier John Tiltman]] in the Research Section teased out the two plaintexts and hence the [[keystream]]. Then, after three months of the Research Section failing to diagnose the machine from the almost 4,000 characters of key, the task was handed to mathematician [[W. T. Tutte|Bill Tutte]]. He applied a technique that he had been taught in his cryptographic training, of writing out the key by hand and looking for repetitions. Tutte did this with the original teleprinter 5-bit [[Baudot code]]s, which led him to his initial breakthrough of recognising a 41 character repetition.<ref name=Sale/><ref>{{Harvnb|Tutte|1998|pp=356, 357}}</ref> Over the following two months up to January 1942, Tutte and colleagues worked out the complete logical structure of the cipher machine. This remarkable piece of [[reverse engineering]] was later described as "one of the greatest intellectual feats of World War II".<ref name=Sale/>
| |
| | |
| After this cracking of Tunny, a special team of code breakers was set up under [[Ralph Tester]], most initially transferred from [[Alan Turing]]'s [[Hut 8]]. The team became known as the [[Testery]]. It performed the bulk of the subsequent work in breaking Tunny messages, but was aided by machines in the complementary section under [[Max Newman]] known as the [[Newmanry]].<ref>{{Harvnb|Roberts|2009}}</ref>
| |
| | |
| ===Decryption machines: world's first programmable computer===
| |
| Several complex machines were built by the British to aid the attack on Tunny. The first was the [[British Tunny]].<ref>{{Harvnb|Halton|1993}}</ref><ref>[http://www.theregister.co.uk/2011/05/26/bletchley_park_tunny_rebuild_project/ Bletchley Park completes epic Tunny machine] The Register, [http://www.theregister.co.uk/2011/05/26/ 26th May 2011], Accessed may 2011</ref> This machine was designed by Bletchley Park, based on the [[reverse engineering]] work done by Tiltman's team in the Testery, to emulate the Lorenz Cipher Machine. When the pin wheel settings were found by the Testery, the Tunny machine was set up and run so that the messages could be printed.
| |
| | |
| A family of machines known as "[[Heath Robinson (codebreaking machine)|Robinsons]]" were built for the Newmanry. These used two [[paper tape]]s, along with logic circuitry, to find the settings of the ''chi'' pin wheels of the Lorenz machine.<ref>{{Harvnb|Copeland|2006|p=66}}</ref> The Robinsons had major problems keeping the two paper tapes synchronized and were relatively slow, reading only 2000 characters per second.
| |
| | |
| The most important machine was the [[Colossus computer|Colossus]] of which ten were in use by the war's end. They were the world's first large-scale programmable electronic digital [[computer]]s, the first becoming operational in December 1943. These were developed by senior engineer [[Tommy Flowers]] at the [[Post Office Research Station]] at [[Dollis Hill]] in London. Like the later [[ENIAC]] of 1946, Colossus did not have a [[stored program]], and was programmed through plugboards and jumper cables. It was faster, more reliable and more capable than the Robinsons, so speeding up the process of finding the Lorenz ''chi'' pin wheel settings. Since Colossus generated the putative keys electronically, it only had to read one tape. It did so with an optical reader which, at 5000 characters per second, was driven much faster than the Robinsons' and meant that the tape travelled at almost 30 miles per hour (48 km/h).<ref>{{Harvnb|Flowers|2006|p=100}}</ref> This, and the clocking of the electronics from the optically read paper tape sprocket holes, completely eliminated the Robinsons' synchronisation problems.
| |
| | |
| ===Testery executives and Tunny codebreakers===
| |
| * [[Ralph Tester]] linguist and head of Testery
| |
| * [[Jerry Roberts]] shift-leader, linguist and senior codebreaker
| |
| * Peter Ericsson shift-leader, linguist and senior codebreaker
| |
| * Victor Masters shift-leader
| |
| * [[Denis Oswald]] linguist and senior codebreaker
| |
| * [[Peter Hilton]] codebreaker and mathematician
| |
| * [[Peter Benenson]] codebreaker
| |
| * Peter Edgerley codebreaker
| |
| * John Christie codebreaker
| |
| * John Thompson codebreaker
| |
| * [[Roy Jenkins]] codebreaker
| |
| * Tom Colvill general manager
| |
| | |
| By the end of the war, the Testery had grown to 9 cryptographers, 24 ATS girls -which is how the women serving that role were then called- with a total staff of 118, organised in 3 shifts working round the clock.
| |
| | |
| ==See also==
| |
| * [[Enigma machine]]
| |
| * [[Newmanry]]
| |
| * [[Testery]]
| |
| * [[STURGEON (cryptography)|Sturgeon]]
| |
| * [[Turingery]]
| |
| * [[Cryptanalysis of the Lorenz cipher]]
| |
| | |
| ==Notes==
| |
| {{reflist}}
| |
| | |
| ==References==
| |
| * {{Citation | last = Churchhouse | first = Robert | title = Codes and Ciphers: Julius Caesar, the Enigma and the Internet | place = Cambridge | publisher = Cambridge University Press | year = 2002 | isbn = 978-0-521-00890-7 }}
| |
| * {{Citation | editor-last = Copeland | editor-first = B. Jack | editor-link = Jack Copeland | title = Colossus: The Secrets of Bletchley Park's Codebreaking Computers | place = Oxford | publisher = Oxford University Press | year = 2006 | isbn = 978-0-19-284055-4 }}
| |
| * {{ Citation | last = Copeland | first = Jack | authorlink = Jack Copeland | year = 2006 | title = The German Tunny Machine }} in {{Harvnb|Copeland|2006|pp=36–51}}
| |
| * {{ Citation | last = Copeland | first = Jack | authorlink = Jack Copeland | year = 2006 | title = Machine against Machine }} in {{Harvnb|Copeland|2006|pp=64–77}}
| |
| * [[Donald W. Davies|Davies, Donald W.]], ''The Lorenz Cipher Machine SZ42'', (reprinted in ''Selections from Cryptologia: History, People, and Technology'', Artech House, Norwood, 1998)
| |
| * {{Citation | last = Flowers | first = Thomas H. | author-link = Tommy Flowers | title = Colossus | year = 2006 }} in {{Harvnb|Copeland|2006|pp=91–100}}
| |
| * {{ Citation | last = Good | first = Jack | author-link = I. J. Good | year = 1993 | title = Enigma and Fish }} in {{Harvnb|Hinsley|Stripp|1993|pp=149–166}}
| |
| * {{Citation | last = Good | first = Jack | author-link = I. J. Good | last2 = Michie | first2 = Donald | author2-link = Donald Michie | last3 = Timms | first3 = Geoffrey | title = General Report on Tunny: With Emphasis on Statistical Methods | year = 1945 | id = UK Public Record Office HW 25/4 and HW 25/5 | url = http://www.alanturing.net/turing_archive/archive/index/tunnyreportindex.html | accessdate = 15 September 2010 }} That version is a facsimile copy, but there is a transcript of much of this document in '.pdf' format at: {{Citation | last = Sale | first = Tony | author-link = Anthony Sale | title = Part of the "General Report on Tunny", the Newmanry History, formatted by Tony Sale| year = 2001 | url = http://www.codesandciphers.org.uk/documents/newman/newman.pdf | accessdate = 20 September 2010 }}, and a web transcript of Part 1 at: {{Citation | last = Ellsbury | first = Graham | title = General Report on Tunny With Emphasis on Statistical Methods | url = http://www.ellsbury.com/tunny/tunny-001.htm | accessdate = 3 November 2010 }}
| |
| * {{Citation | last = Halton | first = Ken | title = The Tunny Machine | year = 1993 }} in {{Harvnb|Hinsley|Stripp|1993|pp=167–174}}
| |
| * {{Citation | editor-last = Hinsley | editor-first = F.H. | editor-link = Harry Hinsley | editor2-last = Stripp | editor2-first = Alan | year = 1993 | origyear = 1992 | title = Codebreakers: The inside story of Bletchley Park | publication-place = Oxford | publisher = Oxford University Press | isbn = 978-0-19-280132-6 }}
| |
| * {{ Citation | last = Hinsley | first = F.H. | author-link = Harry Hinsley | year = 1993 | title = An introduction to Fish }} in {{Harvnb|Hinsley|Stripp|1993|pp=141–148}}
| |
| * {{ Citation | last = Klein | first = Melville | title = Securing Record Communication: The TSEC/KW-26 | url = http://www.nsa.gov/about/_files/cryptologic_heritage/publications/misc/tsec_kw26.pdf | accessdate = 17 September 2010 }}
| |
| * {{Citation | last = Roberts | first = Jerry | author-link = Jerry Roberts | year = 2006 | title = Major Tester's Section }} in {{Harvnb|Copeland|2006|pp=249–259}}
| |
| * {{Citation | last = Roberts | first = Jerry | author-link = Jerry Roberts | year = 2009 | title = My Top-Secret Codebreaking During World War II: The Last British Survivor of Bletchley Park’s Testery | url = http://www.ucl.ac.uk/news/news-articles/0903/09031601 | format = video | publisher = University College London | format = iTunes U }}
| |
| * {{Citation | last = Tutte | first = W. T. | author-link = W. T. Tutte | title = Fish and I | date = 19 June 1998 | url = http://www.usna.edu/Users/math/wdj/papers/cryptoday/tutte_fish.pdf | accessdate = 7 April 2012 }} Transcript of a lecture given by Prof. Tutte at the [[University of Waterloo]]
| |
| * [http://www.alanturing.net/turing_archive/archive/b/B06/BO6-092.html Entry for "Tunny"] in the [[GC&CS]] ''Cryptographic Dictionary''
| |
| * [http://www.codesandciphers.org.uk/lorenz/fish.htm The Lorenz Cipher and how Bletchley Park broke it] by Tony Sale
| |
| | |
| ==Further reading==
| |
| * Stephen Budiansky, ''Battle of Wits'' (Free Press, New York, 2000). Contains a short but informative section (pages 312–315) describing the operation of Tunny, and how it was attacked.
| |
| * Paul Gannon, ''Colossus: Bletchley Park's Greatest Secret'' (Atlantic Books, 2006). Using recently declassified material and dealing exclusively with the efforts to break into Tunny. Clears up many previous misconceptions about Fish traffic, the Lorenz cipher machine and Colossus.
| |
| * F. H. Hinsley, Alan Stripp, ''Codebreakers: The Inside Story of Bletchley Park'' ([[Oxford University Press]], 1993). Contains a lengthy section (pages 139–192) about Tunny, the British attack on it, and the British replicas of the Lorenz machine.
| |
| * {{Citation | last = Small | first = Albert W. | title = The Special Fish Report | year = 1944 | url = http://www.codesandciphers.org.uk/documents/small/smallix.HTM | accessdate = 21 September 2010 }}
| |
| * Michael Smith, ''Station X: Decoding Nazi Secrets'' (TV Books, New York, 2001). Contains a lengthy section (pages 183–202) about Tunny and the British attack on it.
| |
| | |
| ==External links==
| |
| <!-- * [http://home.ecn.ab.ca/~jsavard/crypto/te0301.htm John Savard's page on the Lorenz machine]-->
| |
| * [http://www.codesandciphers.org.uk/lorenz/index.htm Lorenz ciphers and the Colossus]
| |
| * [http://www.eclipse.net/~dhamer/lorenz.htm Information on Lorenz]
| |
| * [http://www.jproc.ca/crypto/tunny.html Photographs and description of Tunny]
| |
| * [http://www.cimt.plymouth.ac.uk/resources/codes/lorenz/default.htm Simplified Lorenz Cipher Toolkit]
| |
| | |
| {{Cryptography navbox | machines}}
| |
| | |
| [[Category:Cryptographic hardware]]
| |
| [[Category:Encryption devices]]
| |
| [[Category:World War II military equipment of Germany]]
| |
| [[Category:Signals intelligence of World War II]]
| |
| [[Category:Broken stream ciphers]]
| |