Talk:Substitution cipher

message: : From article: Modern block ciphers such as DES and Rijndael can be viewed as substitution ciphers on a large alphabet. They treat each 64-bit or 128-bit block of the plaintext as a symbol and perform several rounds of substitutions and transpositions on the bits in the block to effect a general block-to-block substitution. The various block cipher modes of operation are analogous to the various polyalphabetics, while "randomized encryption" is similar to a homophonic substitution.
Matt, I would argue against your statement here that ECB block cyphers are substitution cyphers. While true from a sufficiently advanced level of abstraction, this is too advanced a level of abstraction for the reader we are justified in expecting for this article. Perhaps as an 'advanced perspecitive' note? ww 18:43, 21 Apr 2004 (UTC)
replies: text: Well, while its wording is not particularly helpful, I don't think it's too advanced or abstract a concept, especially placed right after polygraphic substitution; all that's changed is the alphabet. I've seen cryptography tutorials introduce first classical ciphers, then introduce block ciphers using exactly sort of exposition. (It also wasn't originally my statement, I just sharpened it a little). — Matt 19:31, 21 Apr 2004 (UTC)
replies: text: Matt, Can't agree. Should I just edit to try to accomodate and see if you can live with it? I agree that the wording seems reasonable, I just think it's confusing due to LoA issues. Thoughts? ww 20:28, 21 Apr 2004 (UTC)
replies: text:  Well, maybe we could move it to block cipher and just include one sentence in this article like "Some more modern ciphers can be seen as polygraphic substitution ciphers on a binary alphabet; see Block cipher and Substitution box for more detail." ? — Matt 20:43, 21 Apr 2004 (UTC)
replies: text: Matt, Seems reasonable. But the issue is important enough (evidence the original edit and your endoresment) that perhaps more would be well. A comment along the lines of '...depending on the level of abstraction, it is also possible to see modern (ie, bit oriented) cyphers as ..."? This has the virtue of saying _how_ it is that they can be seen that way, without adding likely confusing discussion here. Not just a bald statement that it's possible. In block cypher (or perhaps better in substitution box) we would add a para noting the more general perspective viewpoint. This puts the 'hard stuff' in a technical article which is a virtue, I suspect. A good thing. Shall we? Shall I, will you?  ww 16:46, 22 Apr 2004 (UTC)
replies: text:  Go for it; I can fiddle with what you end up with. (BTW, the stuff about homophonic and randomised encryption in that para looks less useful to me). — Matt 17:25, 22 Apr 2004 (UTC)

text: Looks like some good work; I'll add a few comments tomorrow, but I'm a bit tired tonight to go through it carefully enough! — Matt 20:34, 22 Apr 2004 (UTC)
thread_title: Block cipher substitution

message: * Merge most of the polyalphabetic section into Polyalphabetic cipher; leave one or two summary paragraphs here.
— Matt 03:40, 23 Jul 2004 (UTC)
thread_title: To do

message: "More artistically, though not necessarily more securely, some homophonic ciphers employed wholly invented alphabets of fanciful symbols. (See Poe's The Gold Bug for a literary example; cf. the Voynich manuscript.)"  Is there any good evidence that the Voynich manuscript uses a homophonic cipher?  If not, it should be removed as an example.  (I'm aware that it's been postulated that the Voynich MS is a homophonic cipher, but just about every type of cryptography has been postulated with respect to the Voynich MS.) Chuck 22:52, 12 January 2006 (UTC)
replies: text: And the Gold Bug isn't an example of a homophonic cipher either; I've removed the entire parenthesis. Thanks for spotting that; I remember a decent PD image in David Kahn's The Codebreakers that would illustrate this well. I'll try and get round to scanning it in. Matt Crypto 09:30, 13 January 2006 (UTC)
thread_title: [[Voynich manuscript]]?

message: "In the same De Furtivis Literarum Notis mentioned above, della Porta actually proposed such a system, with a 26 x 26 tableau filled with 676 unique glyphs."
A small point, but della Porta used only 20 letters in Latin and Italian.
--Steve 04:29, 4 June 2006 (UTC)
replies: text: You're right, well spotted. I corrected it, thank you. (Note that you can edit articles!) -- Securiger 09:23, 7 June 2006 (UTC)
thread_title: Porta's Diagrammatic Digraph

message: According to The Code Book, homophonic substitution is monoalphabetic because one letter in the cipher can only match to a single letter in the plaintext, even though a single letter in the plaintext can be matched to multiple letters in the ciphertext. (oh, and I accidentally hit enter too soon when typing the description of my change)  --Sydius (talk) 00:14, 19 August 2008 (UTC)
thread_title:  Homophonic substitution is monoalphabetic 

message: I think nomenclator isn't really homophonic, so I split the section and gave nomenclator its own section. --Sydius (talk) 00:23, 19 August 2008 (UTC)
replies: text: I put it back to the way it is, since I'm not 100% sure. --Sydius (talk) 00:40, 19 August 2008 (UTC)
thread_title:  Nomenclatur homophonic? 

message: This needs more context explaining what is encrypted or who does/n't get the keys or why. Without that it's an odd detail that doesn't belong in this article.  —Preceding unsigned comment added by 173.88.143.41 (talk) 14:49, 18 April 2009 (UTC)
thread_title:  Sales catalogs? 

message: I think the nomenclator in ancient Rome was the slave which walked beside the master in the street, remembering him in a low voice the name of the people they casually met. So, the master could greet other people by name, as if he spontaneously remebered their names. It was particularly useful for political candidates. Lele giannoni (talk) 13:52, 10 August 2011 (UTC)
thread_title:  Nomenclator 

message: Hi. Just stumbled across this page, in its current state.
I'd be curious to know why this anchor is wanted here.
I'm not an expert in WP markup, but I've found a fix that seems to allow the anchor without breaking the page.
As was, the changes were breaking the page, at least for me: I was getting a dashed box around the text "== Simple substitution==" (just like the boxes around the messages further down).  I can provide a screenshot if desired.  But it looked roughly like this:
 == Simple substitution==
The page linked to (Wikipedia:ANCHOR#Section_linking_.28anchors.29) mentions that a terminating </span> is needed somewhere.
I've changed to the  syntax anyway for neatness, but even so it appears headings only like to go on their own line.  So I put a linebreak after the anchor, and forced the TOC to appear before it (otherwise it would go directly before the heading, and after the anchor.)
CountingPine (talk) 22:40, 14 August 2012 (UTC)
thread_title:  &lt;span&gt; revert war 

message: In the Simple Substitution section, shouldn't the Ciphertext alphabet be ZEBRASTUVWXYCDFGHIJKLMNOPQ instead of the given ZEBRASCDFGHIJKLMNOPQTUVWXY? I could be mistaken, but I thought the ciphertext alphabet followed the remainder of the standard alphabet from the end of the key and then starts over at A (or the first unused letter).  Orca239 (talk) 01:53, 10 November 2012 (UTC)
thread_title:  Potential Corrections 

message: The description given in the text wasn't quite accurate. It said:
:Later, the producers created a second alien language that used a combination of replacement and mathematical Ciphers. Once the English letter of the alien language is deciphered, then the numerical value of that letter (1 through 26 respectively) is then added to the value of the previous letter showing the actual intended letter. 
Adding 1 through 26 would mean that two repeated ciphertext symbols meant that the second represents a "Z", but in fact it means the second represents an "A". You need to map the letters to 0 through 25, not 1 through 26.
I fixed it, but it may not be clear as written to someone who doesn't think like a programmer, so someone may want to go over it. --50.0.128.185 (talk) 03:08, 19 March 2016 (UTC)
thread_title:  Futurama "Alien Langugage 2"