Talk:Hill cipher

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[edit] Notation

Nice article! One thing, though: all finite fields have order pⁿ, where p is prime. I think the notation GF(pⁿ) is used to denote these fields. So GF(26ⁿ) cannot be a field because 26 is composite. Would , work? Sorry if I'm wrong, it's quite possible that my maths is getting rusty...! — Matt 17:05, 27 Oct 2004 (UTC)

Aargh, as I'm sure you're aware Matt it's me who is rusty! Please feel free to make the correction, I have to dash away just now. Incidentally a big "To Do" for this article would be finding Hill's patent. Securiger 07:25, 31 Oct 2004 (UTC)

I've made that change. The patent is US patent 1,854,947 but the scans at the USPTO website seem to be broken. I found someone else had scanned some diagrams at the "Crypto Drop Box" though:

• Fig.s 1 and 9
• Fig.s 2, 7 and 8
• Fig. 3, but a bit broken
• Fig.s 4, 5 and 6

I presume that as scans of public documents from more than 70 years ago, it would be OK to use one of these? In particular, Fig. 4 would make a nice illustration. Securiger 13:05, 1 Nov 2004 (UTC)

Yeah, I think these fall into PD. — Matt 01:39, 22 Nov 2004 (UTC)

[edit] Image added

OK, I cropped a copy of that image, shrank it a bit, cleaned up a few glitches, and removed the figures. At the moment it's at the top of the page, since it's the only illustration for the article. But that kind of spoils the surprise (that the cipher was implemented mechanically). Securiger 08:30, 22 Nov 2004 (UTC)

[edit] nice

One might naïvely think that the key size, in bits, is n2log226 or about 4.7n2. In fact, it is slightly less than this because not all randomly selected matrices are usable. A slightly less naïve view might guess that 1/2 + 1/26 of candidate keys would be unusable, reducing the keyspace by about 54%.

Wow, I didn't know encyclopedia articles could be this condescending. I mean, what the fuck? Since when do reference works pass judgment on what is "naïve"? Does Britannica ever try to be this didactic and insulting? —The preceding unsigned comment was added by 68.35.148.201 (talk • contribs) 07:01, 11 February 2006 (UTC)

Feel free dive in and make whatever changes you think are needed. — Matt Crypto 14:39, 11 February 2006 (UTC)

But there is nothing "insulting" or "condescending" about it. "Naïvely" or the "naïve approach" are standard phrases in mathematics -- and many other fields -- to indicate a method which omits various complications (usually, thereby becoming less accurate). And no-one is suggesting that you are naïve (the subject of the phrase is "one", i.e. some hypothetical person), still less that you are socially inept or some such thing. -- Securiger 04:22, 14 February 2006 (UTC)