Talk:Enigma machine/Archive 2

Need to clarify

 * Versions of Enigma were used for practically all German as well as much of the European Axis' radio, and often telegraph, communications throughout the war; even weather reports were encrypted with an Enigma machine. Both the Spanish during the Civil War and the Italians during World War II are said to have used one of the commercial models, unchanged, for military communications. This was unwise, for the British (and presumably others) had succeeded in breaking the plain commercial version(s) or their equivalents.
 * It is estimated that between 100,000 and 200,000 Enigma machines were constructed during World War II. The Japanese are said to have obtained an Enigma machine as early as 1937, although whether they were given it by their German allies, or bought a commercial version which, except for the plugboard and the actual rotor wirings, was essentially the German Army / Air Force machine, is disputed.

We should clarify language like "are said to" and "presumably". Particularly, can we say for certain that the Spanish and Italians used commercial Enigma during WWII? And did the Japanese obtain an Enigma machine as early as 1937? If we can't be certain, we should specify exactly who it is who has speculated along these lines. &mdash; Matt 03:18, 29 Jul 2004 (UTC)
 * Matt, On the question of whether the Japanese had an Engima machine, I have seen a picture of what is claimed to have been a Japanese-built Engima with the rotors arranged horizontally (ie, edge on) instead of face to face as in the Engima. Very nice workmanship apparently. Whether compatible with German military Enigma or not I haven't heard. And I have come across several mentions of Enigmas (presumed from context to be military ones) being shipped from Germany to Japan late in the war but sunk. The 'U-boat supply line' thing, if you remember. Ores and such were planned as well if my understanding is correct.
 * I think I would leave the 'said to' and 'presumably', weasel words though they may be, as more detailed (ie, credible) information is scarce on the ground I'm familiar with, and on the basis that there are rumors floating around (in much published material, not merely urban legend quality stuff) whose existence and content should be, at least inferentially, acknowledged. We should not leave the bushwa (well meant or not) accounts of this history unaddressed.


 * As for versions being used... SD, Army, Navy, Air Force, Abwehr, Italian Navy, all(?) in multiple networks, all used Engima of one sort or another. This is pretty heavy use of one (albeit variants and in multiple networks) machine. The claim is not cast in precise language and the authorial arts of allusion and such do have a place somewhere, in your view, do they not? They do in mine, as I regard the point to be understanding gained, not only hard information passed.


 * Finally, we are back up to 39K even after removals to Ultra. There's a limit to the amount of detail we can put in this article. I'm not quite sure where it is, but surely.... ww 16:11, 29 Jul 2004 (UTC)

Comments
I did not read the entire article, however I read a large majority of it and I would like to say that as far as grammar goes it is superbly written! Jaberwocky6669 03:33, Jul 29, 2004 (UTC)
 * J, We're getting there. Sort of. Fascinating to see that there are >= 6668 other Jaberwockys here on WP. ww 16:16, 29 Jul 2004 (UTC)


 * Lol, I just like to use the number because it makes the name completely senseless. By now I am sure we have 7,000+. Jaberwocky6669 00:31, Jun 26, 2005 (UTC)

French Enigma work
Matt, re your recent reversion in re French Engima work. Should be reversed.

After Poland fell and the Biuro folk were evacuated, they (Rejewski et al) were installed in Paris (and then after the Fall of France at PC Bruno (the British seem to have been reluctant to let them into BP -- but that's only a construal of mine from the odd comment here and there) and the French (under Bertrand) and BP proceeded to work together on Enigma. This was early days for post three_letter_indicator Army Enigma cryptanalysis and the Poles were the world experts at the time. Indeed the only experts anywhere, discounting any playing along by Divine observers. As Turing and crew got up to speed (and addressed Enigma aspects the Poles had taken a pass on, ie Naval Enigma), BP took on more and more of the strain, especially after PC Bruno was shut down. For a while there was a shared work schedule between Fr and BP (and I recall especially between BP and Bruno) and there are records of frustration at BP waiting for the French to (break into this or that was the basic issue I guess).

That France fell has distorted all our impressions of the contributions made before (and after, for that matter) by them. Gamelan is not an outstanding aspect of those contributions, of course, nor Petain nor the Vichyites generally, but... In this case, it is clear that the sequence was 1) nobody (Naval Enigma as Brits and French gave up on it), 2) Poles at the Biuro (between '32/33 and '39 for early Army Engima), 3) jointly French (in Paris and then PC Bruno w/ assistance from evacuated Poles) and BP (on Air Force and Army Engima), 4) after PC Bruno shut down BP alone (all Enigmas), until 5) US began to help at BP after the political pushme pullyou struggles died down, and then finally 6) as US bombes were built and delivered to BP and the girl's schools in Washington, BP and US.

Having reread this just now, I am struck by something I think I've never considered before. Were pre fighting Luftwaffe Engima operations as readable as they were later (relatively, anyway)? And did the Biuro have a run against them or any success? Was there any traffic to be read? Not much of the organizational variety as there were no forward bases prior to Sept 39, but surely there was some wireless traffic? There was Army wireless else the Biuro wouldn't have had much to work on. Or was it intercepted (tapped) telegraphic stuff? Do you know anything? Anyone??

Anyway, I trust this clarifies the motivation behind the edit I made to include the French? Will you restore, or shall I? ww 19:02, 29 Jul 2004 (UTC)


 * I've restored the "In France"; I queried it because I remembered that some mention of the Poles after Poland not being allowed to work on Enigma, and consigned to some lesser ciphers instead. It seems that they did, indeed, continue work on Enigma in France (I found a few references to an "Equipe Z" operating between 1939 and 1942 ) &mdash; Matt 22:22, 29 Jul 2004 (UTC)
 * Matt, An interesting reference you have turned up. It would appear from that that EquipeZ was in fact PC Bruno under a cover name. The dates and circumstances match well enough to make this plausible. But I've never heard the name before. More importantly however, they claim --for the first time I have ever seen -- that the Buiro had broken into German Naval Enigma, and furthermore that they did so before the break in the Army Enigma. This raises a few questions I'm currently ill equipped to investigate as my reference material is inaccessible for the moment.
 * Is this true, or another of the not so reliable factoids about Enigma and its history (and crypto history generally) that this site notes in its opening para?
 * If true, which Naval Engima is meant? The first version (adopted in '27(?)) did not use a stecker and was abandoned when the Army adopted its version some years later (with a stecker). My impression had been that this was due to efficiency (economies of scale in manufacturing I suppose), with perhaps some input from army crypto studies about increased security of the stecker version. But perhaps the primary concern actually was security?
 * The claim is made here that all three Polish musketeers were involved in the first break. This does not square with my memory of most (credible) accounts nor with my memory of Rejewski's own account. In those, the first break was made by Rejewski who was working independently and was done on the famous fundamental mathematical basis. Only then were the others called in. Furthermore, the first breaks into (whichever) Engima required additional clues which came from the message setting procedure (three operator chosen letters repeated twice) which was, it is my understanding, never used by the Navy at any time.


 * I contribute these questions for further study without, alas, answering them. Perhaps, if there is an embryonic urban legend here, we might scotch it early. Or, if true, improve our knowledge and WP content. ww 14:28, 30 Jul 2004 (UTC)

Comment from WP:FAC
If you're more worried about length, then maybe the article should be separated into one on the machine itself (which the article title is anyway) and one on the process of breaking the cipher. You guys seem to have a lot more material to go in, so it would be a shame to not do that just because this article should really only be about the machine anyway. - Taxman 20:53, Jul 29, 2004 (UTC)
 * Perhaps. There's a number of threads to the Enigma topic, and it is proving difficult to fit them all in: 1) A description of the workings and components of the machine; 2) A history of how the machine was developed and evolved, and who used it; 3) The techniques for codebreaking; 4) The history, people and results of the codebreaking (Ultra); 5) How the Enigma story was revealed 30 years (or more) later. As you suggest, perhaps we should stick primarily to 1) and 2) within Enigma machine, and evolve off the other parts into separate articles (I think User:ww also suggested splitting of the cryptanalysis details); of course, we should leave a paragraph or two for each of 3), 4) and 5) to summarise. Actually, maybe this comment should be on the Talk: page... &mdash; Matt 21:15, 29 Jul 2004 (UTC)

Nice work
Wow, nice work on this article at the end of the FAC process. Great details added and important extra info moved off to its own article. The diagrams are great. Keep working on the todo list, and I'm sure this will get even better. - Taxman 23:14, Aug 2, 2004 (UTC)

still Trouble in River City
I've recently noted that the 2005 Mathematics Calendar (they publish them early here in the US -- probably some kind of New World plot, of course) discusses (though briefly) the Enigma code from WWII. Sigh... ww 20:06, 30 Aug 2004 (UTC)

And we may note that some of P G Wodehouse's characters, whatever their other virtues, have troubles too. In Right Ho, Jeeves, there may be found a wire from Augustus Fink-Nottle in response to one from B W Wooster.
 * Cipher telegram signed by you reached me here. Reads 'Lay off the sausages. Avoid the ham.' Wire key immediately. Fink-Nottle

We may note here that the wire sent which evoked this was almost certainly not a either a cypher (which might require a key to understand, perhaps especially amongst Bertie's crowd) nor a code, for we are given the reasoning which produced it earlier in this work. But, not knowning that, as Fink-Nottle did not, it is unreasonable to assume it to by a cipher as these rarely produce intelligible (well, in this case the question is perhaps open...) output. This wire is, if anything clandestine, a code, and Fink-Nottle's request for the key was simply wrong. Fink-Nottle has here, erred in the same unfortunate sense as does the 2005 Mathematics calendar, and many articles here on WP. I've certainly not caught all misuse, I'm sure.

As for those in a quiver to learn the outcome of the Fink-Nottle wire, Bertie responded with


 * Also kidneys. Cheerio. Bertie.

Which clarifies all, of course. ww 19:35, 18 Sep 2004 (UTC)

Rejewski removal

 * (For context, here's my original edit summary: I don't think there's room to mention Rejewski here (else, it'd only be fair to mention Turing, and then...); also, Rejewski's attack depends on procedural flaws anyway) &mdash; Matt 12:38, 19 Sep 2004 (UTC)

Matt, I would disagree as user procedural errors were incidental to his use of maths in the initial analysis. His insight was able to use them, but was independent of them (though perhaps stimulated by them)
 * Not at all; procedural flaws and operator error were integral to Rejewski's recovery of the wiring &mdash; these were, specifically, the doubly enciphered indicator, the use of a global ground setting and the non-random choice of indicators. These factors were quite separate to weaknesses in the Enigma cipher itself. Rejewski exploited all these weaknesses by using theorems about the cycle structure of permutations. &mdash; Matt 12:38, 19 Sep 2004 (UTC)
 * Matt, Just noticed your comment. My memory of his work is different than yours seems to be. His application of group theory and pure math to Enigma analysis was not a result of operator or procedural errors on the part of the Germans. That was his particular contribution, and it covers him and his memory with cryptanalytic glory. That, having done such an analysis, one is faced with finding daily (weekly, monthly, .. I can't remember when they changed around) keys which is rather less ethereal proposition, for which perforated sheets (in the Zygalski implementation) and cyclometers and bombas (first editions) and so on are needed. Less historic distinction there, more workaday stuff, I suppose. ww 20:54, 16 Oct 2004 (UTC)
 * By procedural error, I mean the use of a flawed indicator system. By operator error, I mean the use of non-random indicators. Rejewski's method, as described by Rejewski, exploited both of these weaknesses. If you like, I can give you quotes from his paper. &mdash; Matt 22:08, 16 Oct 2004 (UTC)
 * Matt, We are here talking about different things. I am concentrating on the theoretical analysis by Rewjewski, and you are considering the problems of decrypting messages from particular networks (ie, procedural commonalities). I see no disagreement with what you've said, but with its scope. ww 19:54, 19 Oct 2004 (UTC)
 * No, I'm afraid I'm not talking about decrypting particular messages. I'm talking about the initial theoretical analysis by Rejewski, the one which used mathematical theorems about permutations and which he used to recover the wiring of the rotors. In particular, Rejewski &mdash; in his 1980 paper, "An application of the theory of permutations in breaking the Enigma cipher" &mdash; relates how he decomposes the permutation products AD, BE and CF into A, B, C, D, E and F. A mathematical theorem gets him close, enough to whittle down the choice to "several thousands or several tens of thousands [of] possible solutions". To complete the decomposition, he uses the fact that operators choose guessable indicators, such as the same letter repeated "lll". This was the operator error. The procedural flaw was to use doubly enciphered indicators at all (and a common ground setting); if this was not used, Rejewski's method wouldn't even have been applicable. The paper is available online, as well as some explanatory lecture notes, at Frode Weierud's pages: . &mdash; Matt 22:44, 19 Oct 2004 (UTC)

I too have the impression that Rejewskis success was to a large extent the result of german mistakes. But then, R needed to exploit the fastest way into enigma for effiency reasons, which was enabled infrequent key change asf.. The enigma hardware could have been kept practically unbreakable, had the germans had operated it the best way. It was still attackable, but the effort against "best play" might have been higher than the allied could have mustered (without capture asf.). also Rejewski writes, the germans would have been better off with no message key at all, let alone repeated 2x3 key. I mean Rejewski had rather little practical choice, if he saw a flaw, he expoited it to the full, whether or not his reputation as a "pure mathematician" suggested a more scientific approach independent of op. flaws. 83.129.26.203 22:08, 30 Jan 2005 (UTC)

He deserves mention in prior to Turing fo rthis reason. Turing's insight in re Naval Enigma was also quite good, but was found in the midst of actual Enigma work. Rejewski was working in isolation, was first, and had no context within which to work. Comment?199.97.121.99 19:50, 18 Sep 2004 (UTC)


 * This is in the context of the lead section of the article. The lead section provides a summary of the rest of the article, and it's preferable to omit the details at this stage; we're simply providing the reader with a sweeping survey. If Rejewski dominated the story of the Enigma, it might be necessary to mention him in the lead section, but I think it's clear that, although his contribution was outstanding, he does not play this type of role. From this "distance", it suffices to say that the Germans used the Enigma, and the Allies broke it, and that this was significant. The details can wait till later.


 * Also, this article is primarily about the machine itself, the history, the different versions, a description of how the different parts fitted together, a formula describing the encryption. Cryptanalysis of the Enigma is our main article about the Enigma codebreakers, although we do have a (rather inadequate) summary section here in this article ("Breaking the Enigma &mdash; Ultra").


 * As an aside, regarding the relative "importance" of Turing and Rejewski, I'm not convinced such an analysis is profitable. Turing's primary Enigma "insight" was the Bombe, and this was used for most Enigma traffic, not just Naval. (His most prominent contribution to Naval Enigma was the "Banburismus" procedure.) Without Turing's Bombe, Bletchley Park wouldn't have read even a twentieth of the traffic that they did after May 1940 (when the double-indicator system was changed). &mdash; Matt 12:38, 19 Sep 2004 (UTC)
 * Matt, Again, I've just noticed this. And again, my memory diverges from yours. The Turing bombe design was indeed a considerable advance, but was nevertheless firmly based on Polish work. The diagonal procedure of Welchman was new however. But Turing's work on Enigma was not limited merely to a bombe design or Banburismus, but on the entire mathematical structure of the beast. Here he appears to have been following Rejewski in spirit if not in detail. I'm not very clear at all about how much of R's work at this level was passed on to BP. Turing was director of the Naval Enigma work in Hut (Six -- my memory persistenly reports this as the Naval Hut) and Welchman was his nr 2 when he came up with the diagonal business. Turing was more important, I think, than you suggest and in more ways. But R still made **the** breakthrough. ww
 * There is no evidence (as far as I'm aware) that the Turing bombe design was firmly based on Polish work. We can at best speculate as to what inspiration there might have been, but the end results &mdash; the attacks that the machines implement &mdash; have only superficial similarities...the name and the fact that they mechanise the finding of the rotor start position. But the cryptographic attack that they mechanise is completely different, and the actual machines are completely different. (It is hut eight). &mdash; Matt 22:08, 16 Oct 2004 (UTC)
 * Matt, Without access to my notes and materials, I will have to leave things as they are on this point. ww 19:54, 19 Oct 2004 (UTC)

Congratulations on being featured!
Soirry I could not help with this article, but it looks extremely good, and is a good ambassador article for wikipedia. Well done everyone, especially Matt. Rich Farmbrough 10:26, 13 Oct 2004 (UTC)


 * Cheers! You are, of course, very welcome to see if this article could be improved further (I'm sure it can), and there's a bunch of other World War II-era crypto pages that are in dire need of some attention if the subject tickles your fancy (see also World War II cryptography, *gulp*)...! &mdash; Matt 10:45, 13 Oct 2004 (UTC)

thanks to everybody who contributed to this awesome piece of work. i stumbled into the page on a lark yesterday, and it's been a blast for many hours. this and the related articles are top notch. thanks! SaltyPig 15:45, 22 Apr 2005 (UTC)
 * Thanks for the kind comments! &mdash; Matt Crypto 15:53, 22 Apr 2005 (UTC)

Backwards compatibility?
Were any of the various models backwards compatible? Or did units (and submarines, and ships) get upgraded and then somebody back at HQ had to remember which machine to use to transmit to them? Tempshill 17:23, 13 Oct 2004 (UTC)


 * There was some consideration for backwards compatibility. In particular, the four-rotor Naval Enigma, used by the U-boats, was designed so that if the fourth rotor was placed in one of the 26 positions then the machine operated exactly like a three-rotor machine. Still, HQ had to remember exactly who they were transmitting to &mdash; by the end of the war, there were a large number of networks each using completely different daily settings, even though the Enigma machines were the same. &mdash; Matt 22:56, 13 Oct 2004 (UTC)

SecurityFocus cite
On 01 Nov 2004, this article was cited in a SecurityFocus article on phishing. Securiger 06:49, 8 Nov 2004 (UTC)

Definition of 'offset' on rotors and ringsettings
I noticed that many people want to simulate the Enigma but are confused about how the ringsettings works exactly, the direction of the ringsettings (wiring), relative to the rotor and notch etc...

The Offset

As example, let us take rotor type I without any ringsetting offset. You can see that an 'A' is encoded as an 'E', a 'B' encoded as a K, and a 'K' is encoded as an 'N'. Notice that every letter is encoded into any another.

In case of the reflectors, we take Wide B where an 'A' is returned as a 'Y' and the 'Y' is returned as an 'A'. Notice that the wirings are connected each time as a loop between two letters.

When a rotor has stepped, you must take in account the offset to know what the output is, and where it enters the next rotor. If for example rotor I is in the B-position, an 'A' enters at the letter 'B' which is wired to the 'K'. Because of the offset this 'K' enters the next rotor in the 'J' position.

The ringsetting

The ringsettings or 'Ringstellung' are used to change the position of the internal wiring relative to the rotor. They do not change the notch or the alphabet ring on the exterior. Those are fixed to the rotor. Changing the ringsetting will therefore change the positions of the wiring, relative to the turnover-point and start position.

The ringsetting will rotate the wiring. Where rotor I in the A-position normally encodes an 'A' into an 'E', with a ringsetting offset B-02 it will be encoded into 'K'

As mentioned before these encodings only happen after the key is pressed and the rotor has turned. Tracing the signal on the rotors AAA is therefore only possible if a key is pressed while the rotors where in the position AAZ.

Rotor wiring tables

Rotors Kriegsmarine/Wehrmacht/Luftwaffe (3-rotor model)

I  = EKMFLGDQVZNTOWYHXUSPAIBRC

II = AJDKSIRUXBLHWTMCQGZNPYFVOE

III = BDFHJLCPRTXVZNYEIWGAKMUSQO

IV = ESOVPZJAYQUIRHXLNFTGKDCMWB

V  = VZBRGITYUPSDNHLXAWMJQOFECK

Rotors used by Kriegsmarine only (3-rotor M3 and 4-rotor M4 model)

VI = JPGVOUMFYQBENHZRDKASXLICTW

VII = NZJHGRCXMYSWBOUFAIVLPEKQDT

VIII= FKQHTLXOCBJSPDZRAMEWNIUYGV

''Zuzatzwalzen or Greek rotors used by Kriegsmarine. To be inserted before thin reflectors only.''

Beta = LEYJVCNIXWPBQMDRTAKZGFUHOS

Gamma = FSOKANUERHMBTIYCWLQPZXVGJD

Wide reflectors Wehrmacht/Luftwaffe

Reflector B = YRUHQSLDPXNGOKMIEBFZCWVJAT

Reflector C = FVPJIAOYEDRZXWGCTKUQSBNMHL

Thin reflectors Kriegsmarine

Reflector B Thin = ENKQAUYWJICOPBLMDXZVFTHRGS

Reflector C Thin = RDOBJNTKVEHMLFCWZAXGYIPSUQ

Drdefcom 18:34, 4 Dec 2004 (UTC)


 * Dr, Just noticed your magesterial info here. In a regular encyclopedia, this might be 'too detailed'. In WP, I think we need to find a place in one of the Enigma articles for this material. Ideas, anyone? Please keep in mind that, even in a WP table or some such, this is a lot of detail so I think we'll have to be careful to include it gracefully, whereever and however it's gets put in.


 * Great work, Dr! Thanks. ww 00:45, 10 Dec 2004 (UTC)


 * Thanks! Well, all ideas are welcome. I would suggest a new page with a very breef intro on enigma and why this page. For those who don't understand what the hell it is, we could direct then to Enigma. Anybody other ideas ?? Dirk 19:19, 10 Dec 2004 (UTC)


 * Brainstorming here, so bear with me! OK...On DES, we have DES supplementary material, which contains some reference material; maybe something like that could work for Enigma machine? It does occur to me, though, that a lot of information on this page verges towards being too detailed at times. This is not a problem as such (more an advantage!), but it suggests that we could apply "Summary style", which means we would factor out various sections into sub-articles, and replace them with summarised sections, so there could be a History of the Enigma machine to discuss the development of the various commercial and military versions. There could be a Technical description of the Enigma machine, or some such. There could be a Procedures for using the Enigma machine, as well, as we only include one out of many indicator schemes. &mdash; Matt Crypto 20:09, 10 Dec 2004 (UTC)

Table in progress

 * Here's the storm in my (little) brain. The problem with the approach of sub-articles is that the article itself may not water down to a table of content. The mainpage should have enough information and story to catch te reader. Too much info isn't good, but too little neither. The difficult part then, is to select what, and how many there's to be send to the sub. Sending interesting pieces to the sub could harm the article. My my, it's difficult Dirk 10:28, 12 Dec 2004 (UTC)


 * Ay, there's the rub. Shakespeare said, or should have. The cryptiac group has been 'rasslin with this for some time. See for instance, the talk history at cryptography, at the WikipediaProject Cryptography, at secret sharing, and elsewhere. It is, I think, an eternal question for which the situation seems to preclude a definitive answer. Consider only the cypher v cipher spelling question!
 * Withall, and wherever it gets put, you're doing good work. Re congrats. ww 20:43, 16 Dec 2004 (UTC)


 * The subarticle on rotor details is a fact! Since I'm not that experienced in Wiki, i have a question: Maybe the "Enigma rotor details" can be 'part of the Enigma article' as shown in the blue box on the top right of the enigma article, but i have no idea how this is done...
 * PS: thanks to the person who changed the wiring table into a real table. Now I know how that works ;-) Dirk 12:16, 18 Dec 2004 (UTC)


 * Good stuff! The blue box is implemented using a "Template"; in the wikicode for Enigma machine at the top there's a little snippet . Basically, templates allow you to include one page directly into another; so in this case, the contents of Template:EnigmaSeries are copied into Enigma machine automatically by the Wikipedia software. So, whenever you see , you can edit it by visiting Template:Foo; there's more detail at Help:Template. In this case, I've added an "edit this box" to make it a little easier. &mdash; Matt Crypto  15:06, 18 Dec 2004 (UTC)

History and movies
Why were my brief critiques of the two Enigma-related movies deleted? Citing, without due comment, fictional misrepresentations of history is tantamount to a tacit approval of disinformation. It's all right to say that an Enigma machine used in one of the movies is authentic&mdash;but not that the whole premise of the movie is a fabrication? Logologist 15:40, 8 Feb 2005 (UTC)
 * I removed them because I think it's too much detail for this topic; by all means include this information in the U-571 article or the Enigma (2001 film)/Enigma (novel) articles. It's OK to briefly cite notable examples of where Enigma crops up in fiction from time to time, but launching into reviews about the historical authenticity of this or that film seems &mdash; at least to me &mdash; to be drifting off-topic. Here, we're focused on details about a specific piece of electromechanical equipment. &mdash; Matt Crypto 16:03, 8 Feb 2005 (UTC)

reordering the "in combination with" section?
".. only their combination with other significant factors which allowed codebreakers to read messages: captured machines and codebooks, mistakes by operators, and procedural flaws. "

Most references I've read downplay the importance of captured gear and emphasize usage errors. Usage generally improved over the course of the war, but the codebreakers kept pace with the improvements and used their knowledge of usage patterns learned from previous breaks to help them get through process changes.

To this day, usage errors remain the primary way system designers hurt themselves with ciphers.

How about:

".. only their combination with other significant factors which allowed codebreakers to read messages: mistakes by operators, procedural flaws, and the occasional captured machine or codebook."

Thoughts? --Sommerfeld 22:45, 2005 Feb 10 (UTC)
 * Sounds good to me. The impression I get is that while captured material was useful for making entries into difficult systems (like Naval Enigma, for example), most of the day-to-day codebreaking was greatly eased by constant operator errors &mdash; predictable cribs, cillies, etc. &mdash; Matt Crypto 23:08, 10 Feb 2005 (UTC)
 * Done. --Sommerfeld 02:53, 2005 Feb 12 (UTC)