Talk:Cryptography

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Please update this rating as the article progresses, or if the rating is inaccurate. Click to show/hide comments. Please add to or update the comments to suggest improvements to the article. I don't think this article would pass a Good Article Review at the moment, because of the lead and the referencing. Geometry guy 23:10, 16 June 2007 (UTC)

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Additional information: FA This article has been rated as FA-Class on the assessment scale. ??? This article has not yet received an importance rating on the assessment scale. This article is a vital article. The following comments have been left for this page: I don't think this article would pass a Good Article Review at the moment, because of the lead and the referencing. Geometry guy 23:10, 16 June 2007 (UTC) (edit)

To-do list for Cryptography:	edit · history · watch · refresh
Give an overview of cryptography standards: at least, what they are and some important examples. Wikilink to a few of the most popular protocols, e.g., Secure Sockets Layer in the "Cryptographic protocols" section.
Priority 1 (top)

• /archive1 - February-May 2004
• /archive2 - Aug 2004-March 2006
• /archive3 - March 2006-June 2006
• /archive4 - June 2006-December 2006

Technically, some Ciphers use the same algorithm for encryption and decryption.For example: one time pad. —Preceding unsigned comment added by 134.2.172.190 (talk) 15:29, 19 January 2008 (UTC)

[edit] Engineering vs. Malevolence

It says in the article "Cryptography is also a branch of engineering, but an unusual one as it deals with active, intelligent, and malevolent opposition (see cryptographic engineering and security engineering); all other kinds of engineering need deal only with neutral natural forces." I'd argue that there are other fields which have to deal with malevolent forces. What about constructing structures and vehicles which withstand attack? Or designing weapons which to deal with the defenses? Or even designing defenses specifically from the weapons (radar jamming, etc)?

Daemon 16:43, 19 January 2007 (UTC)

Personally, I don't really buy that Cryptography is a branch of engineering. Security engineering is, I suppose, but that's a related field, not the same thing. Mangojuice^talk 18:13, 19 January 2007 (UTC)

Crypto uses experimental evidence and experience, folk wisdom, joint experience of many, mathematical proof, scientific theories, etc to develop systems and procedures and so on. This is a pretty good description of engineering, not of a science. Seems a reasonable chocie of term to me. ww 11:10, 9 March 2007 (UTC)

[edit] removal of reading to links section

Several of these are in fact actual books, and should not have been moved. The others are less easily classified and may belong in a links section. These should be reviewed. There is, in this group, no easy way to automatically classify them. The test should be size, formality, perhaps existence as a dead tree production, nad importance to the field. ww 11:10, 9 March 2007 (UTC)

[edit] Enigma Picture

I don't understand the picture describing the enigma machine. Is the picture just an in screen shot taken from some game? - 74.104.164.160 01:16, 8 May 2007 (UTC)

Yeah, apparently it was. The image that was apparently intended was commons:Image:Enigma.jpg. That would show up by default at Image:Enigma.jpg except that there is already a different image there. Mangojuice^talk 13:53, 8 May 2007 (UTC)

[edit] terminology

The taxonomy is that cryptosystems produce crypttext (either codetext or cyphertext) after processing of plaintext. That usage is not congruent with the taxonomy should not justify use of confusing terminoloty in a WP article. We should be precise, even if usage isn't, mostly. Hence the rollback. ww 09:08, 13 July 2007 (UTC)

Please give references for your claim. In all the crypto books I have ciphertext is the result of an encryption. Crypttext is not even used once. 85.1.111.99 10:33, 13 July 2007 (UTC)

I did some more searching for the term crypttext. Google booksearch gives almost no results. A normal Google search seems to indicate that crypttext is almost exclusively used by PHP programmers to distinguish raw, unformatted ciphertext (which is the thing they call crypttext) from other formats. PHP programmers can of course use their own terminology if that helps them to keep different formats appart. But wikipedia should go with the most common use, that is calling the result of an encryption ciphertext. 85.1.111.99 11:36, 13 July 2007 (UTC)

Concur with 85.1.111.99. Dictionary.com has no definition for "crypttext" but has "ciphertext." I've been working in the crypto field since college and I've never once heard "crypttext" until now. Mangojuice^talk 12:47, 13 July 2007 (UTC)

Cryptology is usually defined as the combined study of cryptography and cryptanalysis. I've amended the terminology section accordingly and cited the dictionary definition of cryptology to back up this (Merriam-Webster's). Ross Fraser (talk) 01:19, 1 February 2008 (UTC)

[edit] DES strength

"DES was designed to be secure against differential cryptanalysis" This seems like a poor wording. Secure implies that it cannot be attacked using differential cryptanalysis. However DES of course can be attacked in this way, it is simply difficult. Skimming the cited article, it never claims that the NSA/IBM thought it would be impossible to use differential cryptanalysis, just that one of their parameters was to make DES difficult to attack using DC. I think a wording to replace "secure against" would be "resistant to". --128.2.225.42 17:41, 19 July 2007 (UTC)

Done. If you see anything else similar, you can just go ahead and make the change. See Wikipedia:Be bold in updating pages - it's a Wikipedia philosophy. Mangojuice^talk 19:38, 20 July 2007 (UTC)

[edit] Extraordinary claims

AceVentura wrote a comment here about the terrible Ed Trice article. Thanks Ace for "sounding the alarm" on this. I moved the comment and discussion of this to the talk page of WikiProject Cryptography. Please continue the discussion there. --David Göthberg 14:54, 29 July 2007 (UTC)

[edit] interactive proof

This link in section Cryptographic protocols is quite misleading, is anyone able to fix it? 85.128.91.247 13:14, 1 September 2007 (UTC).

Actually you are. :) But I did it. It now links to Interactive proof system, which is the right place. Mangojuice^talk 16:05, 1 September 2007 (UTC)

[edit] hai

hello —Preceding unsigned comment added by 203.129.246.33 (talk) 07:38, 3 September 2007 (UTC)

[edit] Another terminology question

It is said Some use the terms cryptography and cryptology interchangeably and this is used in wikipedia as cryptology redirects here. I have checked a few places, for example Britannica and Mirriam Webster Dict. and they make a difference, moreover the etymology is different. Could anyone give some references to publications where both terms mean the same? Has it been earlier discussed, or the mater is so obvious? Best, kuszi 13:25, 8 September 2007 (UTC).

Albrecht Beutelspacher in Cryptology says that the two can be used interchangeably. Some people use "Cryptography" to mean the science of writing secret messages, "cryptanalysis" to mean the breaking of encrypted messages and "cryptology" to mean cryptanalysis and cryptography combined. Others just label the whole field as "cryptography". This has been discussed at Talk:Cryptography/Archive 1#cryptology duplicates cryptography? a merge proposal, Talk:Cryptography/archive2#Cryptology = cryptography + cryptanalysis ? and probably in a few other places. Hut 8.5 14:28, 8 September 2007 (UTC)

Thank you for the response, however I am quite satisfied. Even if we agree with prof. Beutelspacher, please consider it important he titled the book, Kryptologie (original was written in German), not Kryptographie like the main article in wikipedia. Best kuszi 10:46, 9 September 2007 (UTC).

Well, I for one prefer "Cryptography" as the title because I draw the distinction differently. I think of cryptography as the subject and cryptology as the academic study of that subject, and this article is not just about the study of cryptography but also its use. In practical terms it doesn't matter much because we have the redirect, but I do note that many articles open with a line like "In cryptography, a digital signature is..." et cetera. Mangojuice^talk 17:01, 10 September 2007 (UTC)

Well, I do agree that the word cryptograpy is used more common comparing to cryptology, but I don't agree that it is the reason to change its meaning, we are writing encyclopedia, do we? We use cryptography, while we use cryptographic techniques, other way we are cryptoanalysists. If it is said "In cryptography, a digital signature is...", the part of cryptology is considered, am I wrong? Possibly it would be better to entitle the article cryptology and to make a redirect from cryptography? Best, kuszi 21:08, 14 September 2007 (UTC).

I don't understand what you mean. The usage we both quoted is perfectly fine as-is. I looked at the dictionary definitions in Miriam-Webster that you linked to, and it backs up my interpretation: Cryptology is the scientific study of crytography. We could stand to find a source for the claim that they're used interchangeably, though. Mangojuice^talk 21:46, 14 September 2007 (UTC)

By Miriam-Webster Cryptology is the scientific study of crytography and cryptanalysis - both of them.

We have Cryptanalysis subsection, and section titled History of cryptography and cryptanalysis. What is the article about: the study of cryptography (or cryptology as scientific study) and use of cryptography (or use of cryptography and cryptanalysis), possibly I do not get the main idea. Best, kuszi 14:15, 16 September 2007 (UTC).

This article is a general overview of cryptography, cryptology, cryptanalysis, all of them. So the article is about (1) the use and techniques of cryptography, (2) cryptanalysis, and also (3) the study of these, but this last is least directly important; it is merely a natural thing to cover while covering (1) and (2). Anyway, I altered the lead sentence; it was incorrectly describing cryptography as the "study"; really, "practice and study" is better. And also, I changed "message secrecy" to "hiding information" because the information being hidden isn't always a "message." Mangojuice^talk 13:56, 18 September 2007 (UTC)

Cryptography is not a science, though it draws from scientific results. Cryptography is not mathematics, though modern cryptography relies heavily on it. And cryptography (either on the system development side or on the cryptanalysis side) is not a scientific enterprise. This is in the strict sense of science, hypothesis / experimental test (in part to develop additional data)) / revision of hypothesis. In the sense of careful and systematic reasoning from available data, certainly. But there is a reason that most accounts speak of the art and science of cryptography -- there is a great deal of art involved that cannot be reduced or systematized. We cover, in the various crypto corner articles, a great deal of that which can be systematized. And the links point to more on the net. Beyond introductory ideas, the subject is highly technical and mathematical, both of which push it to the boundary of what's suitable for a genreal purpose encyclopedia like WP. If you want a coherent account of that, I suggest you look into some of the references. Goldreich is well thought of, Stimson is widely used in university courses, Anderson's Security Engineering is excellent in providing a wider perspective than only algorithms and ways to break them.

Our history article is a good introduction and provides perspective on the field and its development. Worth reading. ww 06:39, 17 September 2007 (UTC)

I do not state that the article is worthless to read, contrary I have read it quite carefully. Please take to account that your post little contradicts the definition given in the article (as a branch of both mathematics and computer science). Best, kuszi 08:00, 18 September 2007 (UTC).

Separate from the debate above concerning whether cryptography is used as a synonym for cryptology (and I agree that this is often done in all but the most formal discussions), the definition of cryptology must be made clear. Cryptology is defined as the combined study of cryptography and cryptanalysis. I've amended the terminology section accordingly and cited the dictionary definition of cryptology to back this up (Merriam-Webster's). This is surely useful to the reader, as the term cryptology isn't used elsewhere in the article. Ross Fraser (talk) 01:19, 1 February 2008 (UTC)

Ross, The usage is not so inflexible as you suggest. But nevertheless, this issue was settled for WP purposes some time ago. At one time there was a series of articles under the headings of both cryptology and cryptography. Cryptiacs active at the time decided to collapse the cryptology tree, leaving pointers. Since that time, large numbers of links and references have cemented that decision into something rather fixed. I think this has long ago been OBE. See one of the archives for this page (the 1st, I think) for the decision. ww (talk) 09:29, 1 February 2008 (UTC)

[edit] Adi Shamir warning of hypothetical exploitation of math flaws in processors

I don't want to step on the toes of more experienced editors of this and other cryptography articles, but I really think the substantive material in the cited New York Times story by John Markoff is worthy of inclusion in this article, and possibly the one on side channel attacks as well. I added the additional opening qualifier of "Hypothetically" to begin the sentence when I reinserted it, but if someone wants to delete it again (which is fine), could they at least explain more fully here on this page why they don't think it is worthy of mention? Given the stories that do make it to the press about errors in embedded processor code (and all the many more errors that are likely never publicized), it seems like a legitimate concern for potential future attacks on public-key cryptographic transactions, even though Shamir notes that he knows of no such attacks yet. No barometer of intelligence (talk) 18:07, 19 November 2007 (UTC)

I have trouble seeing how a minor set of attacks that might be possible should be mentioned in the main article. Mention in the NYT isn't by itself a good enough reason. There may be an article on cryptography other than the main one where this makes more sense. JoshuaZ (talk) 18:42, 19 November 2007 (UTC)

Point taken. Can you suggest another article in which inclusion of the story might be more appropriate? Perhaps the one on Shamir himself? No barometer of intelligence (talk) 19:09, 19 November 2007 (UTC)

A big problem is that the NYT article is very vague. It is already well known that errors can leak private keys. See for example Kocher's comment in the article. Shamir quite likely doesn't reiterate old results. So it seems that the NYT article may insufficently describe Shamir's paper. Quite possibly the paper is worth mentioning, but we can't say much before the paper is published. 85.1.100.239 (talk) 21:44, 19 November 2007 (UTC)

Understood. I removed the mention. It may be a case of the so-called "main stream media" being deficient to explain intricate technical subjects without losing a substantial portion of their readership. If I see a more detailed mention of Shamir's research note to his colleagues elsewhere, I'll bring it to the attention of other editors here before trying to include it in this or any other article. Thanks for the feedback. No barometer of intelligence (talk) 22:02, 19 November 2007 (UTC) P.S. and mea culpa - It appears the mass media reporting about Shamir's note was much ado about little, if not nothing, according to this Computerworld story:[1] Sorry. No barometer of intelligence (talk) 22:34, 19 November 2007 (UTC)

I don't see a need to apologize here. Shamir's note likely describes what is known as a fault attack. There are quite a number of research papers analyzing such attacks. Some cryptographic libraries take these attacks serious and implement countermeasures. It might be a good idea to start a new wiki page on fault attacks pointing to some of the known results. Certainly it would be great to have access to Shamir's note. E.g., a serious implementor would probably want to know if countermeasures against such attacks are necessary (rsp. should be improved). Neither the NYT nor the Computerworld article are of any help there. 85.2.41.154 (talk) 07:53, 20 November 2007 (UTC)

If we want to improve coverage in this area, I would think the best idea would be to talk about attacks based on measuring power consumption or magnetic field fluctuations; those are well-established, well-noted issues. Mangojuice^talk 14:33, 20 November 2007 (UTC)

[edit] more/better references/footnotes

The first two sections (counting the intro) have no references. --Thinboy00 ^talk/_contribs @70, i.e. 00:40, 20 November 2007 (UTC)

The intro doesn't necessarily need references. It's just a summary of the content in the article (which should be referenced). Hut 8.5 07:57, 20 November 2007 (UTC)

[edit] pair vs set

"A cipher (or cypher) is a pair of algorithms which perform this encryption and the reversing decryption."

Wouldn't "a set of algorithms" be more appropriate?

206.126.85.163 21:36, 22 April 2007 (UTC)

Why? It's normally 2 algorithms: one for enciphering, and one for deciphering. Mangojuice^talk 14:32, 23 April 2007 (UTC)

[edit] Assuaging Persistent Doubters

I occasionally encounter the clearly mistaken assertion that there is a realistic possibility that organizations such as the NSA are capable, within practical time and budget constraints, of breaking all popular ciphers (with the possible exception of One-time pad) of any key length. I have found no succinct statement on Wikipedia explaining, in a manner accessible to the layperson, why this is not a reasonable viewpoint even though it cannot be disproved.

For example, from Schneier:

If I take a letter, lock it in a safe, hide the safe somewhere in New York, then tell you to read the letter, that's not security. That's obscurity. On the other hand, if I take a letter and lock it in a safe, and then give you the safe along with the design specifications of the safe and a hundred identical safes with their combinations so that you and the world's best safecrackers can study the locking mechanism -and you still can't open the safe and read the letter - that's security.

Does this belong on Wikipedia somewhere? (Or is it already here?) AndersJohnson (talk) 05:30, 31 January 2008 (UTC)

The argument you summarize here is a complex one, relying on estimates of future progress in such matters as mathematical research or computer software algorithm developments and similar matters. As such it is hard to handle on WP, which is biased against long contingent explanations of most anything. Furthermore, there will be objections on grounds of Original Research (forbidden by WP policy and enforced by unimaginative Miss Fidditches of several stripes) for most any such account. Of course to the detriment of WP quality. So, as a current practical matter, making the point you suggest will be difficult, in this article or another, despite the fact that it is a perfectly reasonable and indeed central to any understanding of crypto security. And in spite of the absence of any requirement of mathematical mastery to understand the argument. Few crypto evaluations are as easily presented to the lay person.

Great writing skill might be able to make the point, but the general standard of writing on WP does notis, collectivley, show much brilliance.

I'm not sure, absent revision of WP policies being applied in a rote and stolid fashion by too many ignorant of the underlying content of the articles they patrol, just how to get around this. —Preceding unsigned comment added by Ww (talk • contribs) 17:44, 31 January 2008 (UTC)

Ww summarized the problem well. Part of the issue is that Wikipedia is not a textbook, and the point you're talking about sounds like the kind of thing I'd want if I were writing one... or maybe not even that. Maybe it would more be like the answer I would give if someone asked me a question about it. The point about Security via obscurity is made here in the history section; see also Kerckhoff's principle. Mangojuice^talk 18:24, 31 January 2008 (UTC)

[edit] UK v US pendantic lies have to stop

I am so sick of people from here, the UK, trying to discredit or more precisely, incorrectly crediting Brits for things.

Take the following quote for example "In 1997, it finally became publicly known that asymmetric key cryptography had been invented by James H. Ellis at GCHQ, a British intelligence organization, in the early 1970s, and that both the Diffie-Hellman and RSA algorithms had been previously developed (by Malcolm J. Williamson and Clifford Cocks, respectively).[18]"

Complete and utter tripe - everyone, and I mean everyone, working in the field know the technique was invented and propagated in the US, by Americans. The fact that the US shared the technique with Brits working in MI type roles is completely irrelevant. WTF cares is Brits also knew about it? Of course they did the Americans taught them.

That quote completely ruins the entire article and more and more articles are getting this every single day. The British Uni Profs have got to stop telling their students to go into Wiki and make edits that create revisionist history in favor of the UK and against the US (or all other countries for that matter). Instead the UK should be teaching their youth to start showing what they are capable of, doing things like creating this technique, which was done by Americans - not Brits.

Whoever, made this edit, and all edits like it, is a disgrace to the United Kingdom —Preceding unsigned comment added by 157.203.42.50 (talk) 14:47, 7 May 2008 (UTC)

Your porposed UK Uni Prof conspiracy might in fact exist (conspiracies are by definition unknown until uncovered), but the facts you claim are in error are actually well established. Whether you like it or not, and with the added confusion of enforced secrecy confusing all, it's very clear that the article is correct. Ellis, Cocks, and Williamson did invent asymmetric crypto before anyone else. As for the Americans who invented it, as you suggest, one was an Israeli citizen, Adi Shamir, then and still. He's the S in RSA.

Nonetheless, given the possibility that the conspiracy you allege exists, I'd love to see some citation (suitable for use on WP and in this article). ww (talk) 20:30, 8 May 2008 (UTC)