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While working at Bletchley, Turing, who was a talented [[Long-distance running|long-distance runner]], occasionally ran the {{convert|40|mi}} to London when he was needed for meetings,<ref>{{Cite book | last = Brown | first = Anthony Cave | author-link = Anthony Cave Brown | title = Bodyguard of Lies: The Extraordinary True Story Behind D-Day | publisher=The Lyons Press | year = 1975 | isbn = 978-1-59921-383-5 }}</ref> and he was capable of world-class marathon standards.<ref>{{cite news|url=https://www.theguardian.com/commentisfree/2010/mar/10/alan-turing-2012-olympics|title=An Olympic honour for Alan Turing|author=Graham-Cumming, John|newspaper=The Guardian|date=10 March 2010|location=London|access-date=10 December 2016|archive-url=https://web.archive.org/web/20161201171628/https://www.theguardian.com/commentisfree/2010/mar/10/alan-turing-2012-olympics|archive-date=1 December 2016|url-status=live}}</ref><ref>{{cite web | first=Pat | last=Butcher | url=http://www.globerunner.org/index.php/09/in-praise-of-great-men/ | title=In Praise of Great Men | publisher=Globe Runner | date=14 September 2009 | access-date=23 June 2012 | archive-url=https://web.archive.org/web/20130818145759/http://www.globerunner.org/index.php/09/in-praise-of-great-men/ | archive-date=18 August 2013 | url-status=live }}</ref> Turing tried out for the 1948 British Olympic team, but he was hampered by an injury. His tryout time for the marathon was only 11 minutes slower than British silver medallist Thomas Richards' Olympic race time of 2 hours 35 minutes. He was Walton Athletic Club's best runner, a fact discovered when he passed the group while running alone.<ref>{{cite web | last1 = Hodges | first1 = Andrew | author-link = Andrew Hodges | title = Alan Turing: a short biography | url = http://www.turing.org.uk/bio/part6.html | publisher = Alan Turing: The Enigma | access-date = 12 June 2014 | archive-url = https://web.archive.org/web/20130914091359/http://www.turing.org.uk/bio/part6.html | archive-date = 14 September 2013 | url-status = live }}</ref><ref>{{cite news | last1 = Graham-Cumming | first1 = John | author-link = John Graham-Cumming | title = Alan Turing: a short biography | url = https://www.theguardian.com/commentisfree/2010/mar/10/alan-turing-2012-olympics | newspaper = The Guardian | date = 10 March 2010 | access-date = 12 June 2014 | archive-url = https://web.archive.org/web/20141108165218/http://www.theguardian.com/commentisfree/2010/mar/10/alan-turing-2012-olympics | archive-date = 8 November 2014 | url-status = live }}</ref><ref>{{cite web | last1 = Butcher | first1 = Pat | title = Turing as a runner | url = http://www-groups.dcs.st-and.ac.uk/~history/Extras/Turing_running.html | publisher = The MacTutor History of Mathematics archive | date = December 1999 | access-date = 12 June 2014 | archive-url = https://web.archive.org/web/20141113020916/http://www-groups.dcs.st-and.ac.uk/~history/Extras/Turing_running.html | archive-date = 13 November 2014 | url-status = live }}</ref> When asked why he ran so hard in training he replied:

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在布莱奇利工作的时候，图灵是一个天才的长跑运动员，偶尔在会议需要他的时候跑到伦敦，他有能力达到世界级的马拉松水平。图灵参加了1948年英国奥林匹克代表队的选拔，但是他受伤了。他参加马拉松比赛的预选赛时间只比英国银牌得主托马斯 · 理查兹奥运会比赛时间2小时35分钟慢11分钟。他是沃尔顿运动俱乐部最好的跑步者，这个事实是在他独自跑步时超过了大家发现的。当被问及为什么他在训练中如此努力地跑步时，他回答说:{{blockquote|I have such a stressful job that the only way I can get it out of my mind is by running hard; it’s the only way I can get some release.<ref>{{cite web |url=https://kottke.org/18/04/alan-turing-was-an-excellent-runner |first=Jason |last=Kottke |title=Turing was an excellent runner |website=kottke.org}}</ref>}}Due to the problems of [[counterfactual history]], it is hard to estimate the precise effect Ultra intelligence had on the war.<ref>See for example {{cite book|last=Richelson|first=Jeffery T.|title=A Century of Spies: Intelligence in the Twentieth Century|date=1997|publisher=Oxford University Press|location=New York|page=296|author-link=Jeffrey T. Richelson}} and {{cite book|last=Hartcup|first=Guy|title=The Effect of Science on the Second World War|date=2000|publisher=Macmillan Press|location=Basingstoke, Hampshire|pages=96–99|author-link=Guy Hartcup}}</ref> However, official war historian [[Harry Hinsley]] estimated that this work shortened the war in Europe by more than two years and saved over 14 million lives.<ref name="Hinsley 1996">{{citation | last = Hinsley | first = Harry | author-link = Harry Hinsley | title = The Influence of ULTRA in the Second World War | origyear = 1993 | year = 1996 | url = http://www.cix.co.uk/~klockstone/hinsley.htm }} Transcript of a lecture given on Tuesday 19 October 1993 at Cambridge University</ref>Transcript of a lecture given on Tuesday 19 October 1993 at Cambridge University

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在布莱奇利工作的时候，图灵是一个天才的长跑运动员，偶尔在会议需要他的时候跑到伦敦，他有能力达到世界级的马拉松水平。图灵参加了1948年英国奥林匹克代表队的选拔，但是他受伤了。他参加马拉松比赛的预选赛时间只比英国银牌得主托马斯 · 理查兹奥运会比赛时间2小时35分钟慢11分钟。他是沃尔顿运动俱乐部最好的跑步者，这个事实是在他独自跑步时超过了大家发现的。当被问及为什么他在训练中如此努力地跑步时，他回答说:

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【最终版】在布莱切利工作的时候，图灵是一名优秀的长跑运动员，他偶尔也会按照这样的模式跑:需要开会的时候，他会去伦敦，他有能力参加世界级的马拉松比赛。1948年，图灵参加了英国奥运会代表队的选拔，但他受伤了。他的马拉松选拔赛时间只比英国银牌得主托马斯·理查兹(Thomas Richards)的奥运会比赛时间2小时35分钟慢了11分钟。他是沃尔顿运动俱乐部最好的跑步者，当他在独自跑步时超过小组时发现了这个事实。当被问及他为什么在训练中如此努力时，他回答说:{{blockquote|I have such a stressful job that the only way I can get it out of my mind is by running hard; it’s the only way I can get some release.<ref>{{cite web |url=https://kottke.org/18/04/alan-turing-was-an-excellent-runner |first=Jason |last=Kottke |title=Turing was an excellent runner |website=kottke.org}}</ref>}}Due to the problems of [[counterfactual history]], it is hard to estimate the precise effect Ultra intelligence had on the war.<ref>See for example {{cite book|last=Richelson|first=Jeffery T.|title=A Century of Spies: Intelligence in the Twentieth Century|date=1997|publisher=Oxford University Press|location=New York|page=296|author-link=Jeffrey T. Richelson}} and {{cite book|last=Hartcup|first=Guy|title=The Effect of Science on the Second World War|date=2000|publisher=Macmillan Press|location=Basingstoke, Hampshire|pages=96–99|author-link=Guy Hartcup}}</ref> However, official war historian [[Harry Hinsley]] estimated that this work shortened the war in Europe by more than two years and saved over 14 million lives.<ref name="Hinsley 1996">{{citation | last = Hinsley | first = Harry | author-link = Harry Hinsley | title = The Influence of ULTRA in the Second World War | origyear = 1993 | year = 1996 | url = http://www.cix.co.uk/~klockstone/hinsley.htm }} Transcript of a lecture given on Tuesday 19 October 1993 at Cambridge University</ref>Transcript of a lecture given on Tuesday 19 October 1993 at Cambridge University

由于反事实的历史问题，很难精确估计超级情报对战争的影响。然而，官方战争历史学家哈里 · 辛斯利估计，这项工作使欧洲战争缩短了两年多，挽救了1400多万人的生命。1993年10月19日星期二在剑桥大学的演讲稿

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【最终版】我的工作压力很大，唯一的办法就是拼命跑步。

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由于反事实的历史问题，很难估计极端组织的情报对战争的确切影响。然而，官方战争史学家哈里·欣斯利(Harry Hinsley)估计，这项工作使欧洲战争缩短了两年多，挽救了1400多万人的生命。1993年10月19日星期二在剑桥大学的一次演讲的讲稿。

At the end of the war, a memo was sent to all those who had worked at Bletchley Park, reminding them that the code of silence dictated by the Official Secrets Act did not end with the war but would continue indefinitely.<ref name="Collins" /> Thus, even though Turing was appointed an [[Order of the British Empire|Officer of the Order of the British Empire]] (OBE) in 1946 by King [[George VI]] for his wartime services, his work remained secret for many years.<ref>{{cite news | title = Alan Turing: Colleagues share their memories | url = https://www.bbc.co.uk/news/technology-18541715 | date = 23 June 2012 | work = BBC News | access-date = 21 June 2018 | archive-url = https://web.archive.org/web/20180707105436/https://www.bbc.co.uk/news/technology-18541715 | archive-date = 7 July 2018 | url-status = live }}</ref><ref name="thegazette.co.uk">{{cite web|url=https://www.thegazette.co.uk/all-notices/content/114|title=This month in history: Alan Turing and the Enigma code|website=thegazette.co.uk|access-date=6 February 2019|archive-url=https://web.archive.org/web/20190626211800/https://www.thegazette.co.uk/all-notices/content/114|archive-date=26 June 2019|url-status=live}}</ref>

战争结束时，一份备忘录发给了所有在 Bletchley Park 工作过的人，提醒他们《官方机密法案》规定的沉默代码并没有随着战争结束而结束，而是将无限期地继续下去。因此，尽管1946年国王乔治六世因其战时服务而任命图灵为大英帝国勋章军官，他的工作仍然保密了许多年。

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【最终版】战争结束时，所有在布莱切利公园工作过的人都收到了一份备忘录，提醒他们《官方保密法》规定的沉默准则不会随着战争的结束而结束，而是会无限期地继续下去。因此，尽管图灵在1946年被英王乔治六世任命为大英帝国军官(OBE)，但他的工作多年来一直是秘密。

===Bombe===

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=== 炸弹 ===

{{Main|Bombe}}Within weeks of arriving at Bletchley Park,<ref name="Copeland2006p378" /> Turing had specified an electromechanical machine called the [[bombe]], which could break Enigma more effectively than the Polish ''[[bomba (cryptography)|bomba kryptologiczna]]'', from which its name was derived. The bombe, with an enhancement suggested by mathematician [[Gordon Welchman]], became one of the primary tools, and the major automated one, used to attack Enigma-enciphered messages.<ref>{{Citation |last= Welchman |first= Gordon |author-link= Gordon Welchman |orig-year= 1982 |year= 1997 |title= The Hut Six story: Breaking the Enigma codes |page= 81 |location= Cleobury Mortimer, England |publisher= M&M Baldwin |isbn= 978-0-947712-34-1 }}</ref>

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在抵达 Bletchley Park 的几周内，图灵就指定了一种叫做 bombe 的机电设备，这种设备能够比波兰炸弹机(波兰)更有效地破解英格玛密码机，而波兰密码机正是源于此。通过数学家戈登 · 威尔奇曼提出的改进，炸弹成为主要的工具之一，也是主要的自动化工具，用于攻击密码信息。[[File:Bombe-rebuild.jpg|thumbnail|right|A working replica of a [[bombe]] now at [[The National Museum of Computing]] on Bletchley Park|链接=Special:FilePath/Bombe-rebuild.jpg]]The bombe searched for possible correct settings used for an Enigma message (i.e., rotor order, rotor settings and plugboard settings) using a suitable ''[[crib (cryptanalysis)|crib]]'': a fragment of probable [[plaintext]]. For each possible setting of the rotors (which had on the order of 1019 states, or 1022 states for the four-rotor U-boat variant),<ref>Jack Good in "The Men Who Cracked Enigma", 2003: with his caveat: "if my memory is correct".</ref> Jack Good in "The Men Who Cracked Enigma", 2003: with his caveat: "if my memory is correct". the bombe performed a chain of logical deductions based on the crib, implemented [[Electromechanics|electromechanically]].<ref>{{cite web |url=https://www.tnmoc.org/bombe |title=The Turing-Welchman Bombe |website=The National Museum of Computing |access-date=18 March 2021}}</ref>

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在抵达 Bletchley Park 的几周内，图灵就指定了一种叫做 bombe 的机电设备，这种设备能够比波兰炸弹机(波兰)更有效地破解英格玛密码机，而波兰密码机正是源于此。通过数学家戈登 · 威尔奇曼提出的改进，炸弹成为主要的工具之一，也是主要的自动化工具，用于攻击密码信息。

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【最终版】在到达布莱切利公园的几周内，图灵指定了一种叫做bombe的机电机器，它比波兰的bomba kryptologiczna更能破解谜机。数学家戈登·韦尔奇曼(Gordon Welchman)提出了一种增强技术，炸弹机成为攻击谜机加密信息的主要工具之一，也是主要的自动化工具。[[File:Bombe-rebuild.jpg|thumbnail|right|A working replica of a [[bombe]] now at [[The National Museum of Computing]] on Bletchley Park|链接=Special:FilePath/Bombe-rebuild.jpg]]The bombe searched for possible correct settings used for an Enigma message (i.e., rotor order, rotor settings and plugboard settings) using a suitable ''[[crib (cryptanalysis)|crib]]'': a fragment of probable [[plaintext]]. For each possible setting of the rotors (which had on the order of 1019 states, or 1022 states for the four-rotor U-boat variant),<ref>Jack Good in "The Men Who Cracked Enigma", 2003: with his caveat: "if my memory is correct".</ref> Jack Good in "The Men Who Cracked Enigma", 2003: with his caveat: "if my memory is correct". the bombe performed a chain of logical deductions based on the crib, implemented [[Electromechanics|electromechanically]].<ref>{{cite web |url=https://www.tnmoc.org/bombe |title=The Turing-Welchman Bombe |website=The National Museum of Computing |access-date=18 March 2021}}</ref>

该 bombe 搜索可能正确的设置使用一个英格玛消息(即，转子顺序，转子设置和插件板设置)使用一个合适的抄袭: 一个可能的明文片段。对于每个可能的转子设置(大约有1019个状态，或者四旋翼 u 型潜艇的1022个状态) ，杰克 · 古德在2003年的《破解谜团的人》中写道: “如果我的记忆是正确的”。炸弹根据婴儿床执行一系列逻辑推理，用电子机械方式实现。

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【最终版】炸弹机使用一段可能的明文片段来搜索Enigma信息可能的正确设置(即转子顺序、转子设置和配线板设置)。对于每一种可能的旋翼设置(大约有1019个州，或者四旋翼u型潜艇的1022个州)，杰克·古德在2003年的《破解谜机的人》中警告说:“如果我的记忆是正确的”。炸弹在婴儿床的基础上进行了一系列的逻辑推理，这是用电机械实现的。

The bombe detected when a contradiction had occurred and ruled out that setting, moving on to the next. Most of the possible settings would cause contradictions and be discarded, leaving only a few to be investigated in detail. A contradiction would occur when an enciphered letter would be turned back into the same plaintext letter, which was impossible with the Enigma. The first bombe was installed on 18 March 1940.<ref>{{Harvnb|Oakley|2006|p=40/03B}}</ref>

当矛盾发生时，炸弹被发现，并排除了这种情况，继续下一个。大多数可能的设置都会引起矛盾并被丢弃，只剩下少数需要详细调查。当一个加密的字母被转换回同样的明文字母时，矛盾就产生了，这对于恩尼格玛来说是不可能的。第一个炸弹于1940年3月18日安装。

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【最终版】当矛盾发生时，炸弹就会探测到，排除那个设定，继续下一个设定。大多数可能的设置都会引起矛盾而被丢弃，只留下少数需要详细研究。当一个加密的字母被转换成同样的明文时，就会出现矛盾，而这在谜机中是不可能的。第一架轰炸机于1940年3月18日安装。

By late 1941, Turing and his fellow cryptanalysts Gordon Welchman, [[Conel Hugh O'Donel Alexander|Hugh Alexander]] and [[Stuart Milner-Barry]] were frustrated. Building on the [[Biuro Szyfrów#Gift to allies|work of the Poles]], they had set up a good working system for decrypting Enigma signals, but their limited staff and bombes meant they could not translate all the signals. In the summer, they had considerable success, and shipping losses had fallen to under 100,000 tons a month; however, they badly needed more resources to keep abreast of German adjustments. They had tried to get more people and fund more bombes through the proper channels, but had failed.<ref name=":0">{{Harvnb|Hodges|1983|p=218}}</ref>

到1941年底，图灵和他的密码分析师同事戈登 · 威尔奇曼、休 · 亚历山大和斯图尔特 · 米尔纳-巴里都感到沮丧。在波兰人工作的基础上，他们建立了一个很好的解密英格玛信号的工作系统，但是他们有限的人员和炸弹意味着他们无法翻译所有的信号。在夏天，他们取得了相当大的成功，运输损失已经降到每月不到10万吨; 然而，他们急需更多的资源来跟上德国的调整。他们试图通过适当的渠道获得更多的人和资金更多的炸弹，但失败了。

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【最终版】1941年末，图灵和他的密码分析师同事戈登·韦尔奇曼、休·亚历山大和斯图尔特·米尔纳-巴里感到很沮丧。在波兰人工作的基础上，他们建立了一个很好的破译Enigma信号的工作系统，但他们有限的人手和炸弹意味着他们无法翻译所有的信号。在夏季，他们取得了相当大的成功，航运损失下降到每月10万吨以下;然而，他们急需更多的资源来跟上德国的调整步伐。他们试图通过适当的渠道招募更多的人，资助更多的炸弹，但失败了。

On 28 October they wrote directly to [[Winston Churchill]] explaining their difficulties, with Turing as the first named. They emphasised how small their need was compared with the vast expenditure of men and money by the forces and compared with the level of assistance they could offer to the forces.<ref name=":0" /> As [[Andrew Hodges]], biographer of Turing, later wrote, "This letter had an electric effect."<ref name="Hodges 1983 221">{{Harvnb|Hodges|1983|p=221}}</ref> Churchill wrote a memo to [[Hastings Ismay, 1st Baron Ismay|General Ismay]], which read: "ACTION THIS DAY. Make sure they have all they want on extreme priority and report to me that this has been done." On 18 November, the chief of the secret service reported that every possible measure was being taken.<ref name="Hodges 1983 221" /> The cryptographers at Bletchley Park did not know of the Prime Minister's response, but as Milner-Barry recalled, "All that we did notice was that almost from that day the rough ways began miraculously to be made smooth."<ref>Copeland, ''The Essential Turing'', [http://www.maths.ed.ac.uk/~aar/turingletter.pdf pp. 336–337] {{Webarchive|url=https://web.archive.org/web/20150218142127/http://www.maths.ed.ac.uk/~aar/turingletter.pdf |date=18 February 2015 }}.</ref> More than two hundred bombes were in operation by the end of the war.<ref name="codebreaker">{{cite web | last1 = Copeland | first1 = Jack | last2 = Proudfoot | first2 = Diane | author-link = Jack Copeland | title = Alan Turing, Codebreaker and Computer Pioneer | url = http://www.alanturing.net/turing_archive/pages/Reference%20Articles/codebreaker.html | publisher = alanturing.net | date = May 2004 | access-date = 27 July 2007 | archive-url = https://web.archive.org/web/20070709065520/http://www.alanturing.net/turing_archive/pages/Reference%20Articles/codebreaker.html | archive-date = 9 July 2007 | url-status = live }}</ref>

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10月28日，他们直接写信给温斯顿·丘吉尔解释他们的困难，首先提到的是图灵。她们强调，与军队花费的大量人力和财力相比，她们的需求是多么微不足道，与她们能够提供给军队的援助水平相比，她们的需求又是多么微不足道。正如图灵的传记作者安德鲁 · 霍奇斯后来写道: “这封信产生了电子效应。”丘吉尔给伊斯梅将军写了一份备忘录，上面写着: “今日行动。确保他们得到了他们想要的一切，并给我报告说已经完成了这项工作。”11月18日，特勤处处长报告说，正在采取一切可能的措施。Bletchley Park 的密码专家们并不知道首相的反应，但正如米尔纳-巴里回忆的那样，“我们所注意到的是，几乎从那天起，崎岖的道路奇迹般地变得平坦起来。“ Copeland，The Essential Turing，pp。336–337 .到战争结束时，已有两百多个炸弹投入使用。[[File:Turing-statue-Bletchley 14.jpg|thumb|right|upright|Statue of Turing by [[Stephen Kettle]] at Bletchley Park, commissioned by [[Sidney Frank]], built from half a million pieces of Welsh slate.<ref>{{cite web |title=Bletchley Park Unveils Statue Commemorating Alan Turing |url=http://www.bletchleypark.org.uk/news/docview.rhtm/454075 |access-date=30 June 2007 |archive-url=https://web.archive.org/web/20070630083823/http://www.bletchleypark.org.uk/news/docview.rhtm/454075 |archive-date=30 June 2007 |url-status=live }}</ref>|链接=Special:FilePath/Turing-statue-Bletchley_14.jpg]]

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10月28日，他们直接写信给温斯顿·丘吉尔解释他们的困难，首先提到的是图灵。她们强调，与军队花费的大量人力和财力相比，她们的需求是多么微不足道，与她们能够提供给军队的援助水平相比，她们的需求又是多么微不足道。正如图灵的传记作者安德鲁 · 霍奇斯后来写道: “这封信产生了电子效应。”丘吉尔给伊斯梅将军写了一份备忘录，上面写着: “今日行动。确保他们得到了他们想要的一切，并给我报告说已经完成了这项工作。”11月18日，特勤处处长报告说，正在采取一切可能的措施。Bletchley Park 的密码专家们并不知道首相的反应，但正如米尔纳-巴里回忆的那样，“我们所注意到的是，几乎从那天起，崎岖的道路奇迹般地变得平坦起来。“ Copeland，The Essential Turing，pp。336–337 .到战争结束时，已有两百多个炸弹投入使用。

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【最终版】10月28日，他们直接写信给温斯顿·丘吉尔，解释他们的困难，图灵是第一个。他们强调，与军队的巨大人力和资金支出相比，他们的需求是多么小，与他们能够提供给军队的援助水平相比。正如图灵的传记作者安德鲁·霍奇斯(Andrew Hodges)后来写道:“这封信有一种令人震惊的效果。”丘吉尔给伊斯梅将军写了一份备忘录，上面写道:“今天就行动起来。确保他们能优先得到他们想要的一切，并向我报告，这件事已经完成了。”11月18日，特勤局局长报告说，正在采取一切可能的措施。布莱切利公园的密码学家并不知道首相的反应，但据米尔纳-巴里回忆，“我们所注意到的是，几乎从那天起，崎岖的道路奇迹般地变得平坦了。”到战争结束时，有两百多架炸弹投入使用。[[File:Turing-statue-Bletchley 14.jpg|thumb|right|upright|Statue of Turing by [[Stephen Kettle]] at Bletchley Park, commissioned by [[Sidney Frank]], built from half a million pieces of Welsh slate.<ref>{{cite web |title=Bletchley Park Unveils Statue Commemorating Alan Turing |url=http://www.bletchleypark.org.uk/news/docview.rhtm/454075 |access-date=30 June 2007 |archive-url=https://web.archive.org/web/20070630083823/http://www.bletchleypark.org.uk/news/docview.rhtm/454075 |archive-date=30 June 2007 |url-status=live }}</ref>|链接=Special:FilePath/Turing-statue-Bletchley_14.jpg]]

===Hut 8 and the naval Enigma===

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=== 8号营房和海军谜机 ===

Turing decided to tackle the particularly difficult problem of [[Cryptanalysis of the Enigma#German Naval Enigma|German naval Enigma]] "because no one else was doing anything about it and I could have it to myself".<ref name="MahonP14">{{Harvnb|Mahon|1945|p=14}}</ref> In December 1939, Turing solved the essential part of the naval [[Enigma machine#Indicator|indicator]] system, which was more complex than the indicator systems used by the other services.<ref name="MahonP14" /><ref>{{Harvnb|Leavitt|2007|pp=184–186}}</ref>

图灵决定解决德国海军谜团这个特别困难的问题，“因为没有其他人对此做任何事，而我可以独享它”。1939年12月，图灵解决了海军指示器系统的关键部分，它比其他军种使用的指示器系统更复杂。

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【最终版】

That same night, he also conceived of the idea of ''[[Banburismus]]'', a sequential statistical technique (what [[Abraham Wald]] later called [[sequential analysis]]) to assist in breaking the naval Enigma, "though I was not sure that it would work in practice, and was not, in fact, sure until some days had actually broken."<ref name="MahonP14" /> For this, he invented a measure of weight of evidence that he called the ''[[Ban (unit)|ban]]''. ''Banburismus'' could rule out certain sequences of the Enigma rotors, substantially reducing the time needed to test settings on the bombes.<ref>{{Cite journal|last=Gladwin|first=Lee|date=Fall 1997|title=Alan Turing, Enigma, and the Breaking of German Machine Ciphers in World War II|url=https://www.archives.gov/files/publications/prologue/1997/fall/turing.pdf|journal=Prologue Magazine|volume=Fall 1997|pages=202–217|via=National Archives|access-date=13 April 2019|archive-url=https://web.archive.org/web/20190626211657/https://www.archives.gov/files/publications/prologue/1997/fall/turing.pdf|archive-date=26 June 2019|url-status=live}}</ref> Later this sequential process of accumulating sufficient weight of evidence using decibans (one tenth of a ban) was used in [[Cryptanalysis of the Lorenz cipher]].<ref>{{Citation | last1 = Good | first1 = 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/t/t15/TR15-018.html | at = Part 3 Organisation: 38 Wheel-breaking from Key, Page 293 | access-date = 13 April 2019 | archive-url = https://web.archive.org/web/20190421091539/http://www.alanturing.net/turing_archive/archive/t/t15/TR15-018.html | archive-date = 21 April 2019 | url-status = live }}</ref>

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