Talk:Main Page/Archive 1

This page serves as an archive for clearly Handled topics, as Talk:Main Page is getting a little cluttered.

md5 Collisions?

What about collisions in the md5 algorithm?

What about them? In theory, two dates/stock market prices might end up with the same meetup point. Unlikely, and probably not a terribly big deal? Zigdon 07:39, 21 May 2008 (UTC)

There are situations where cryptographic collisions are a problem, but this isn't one of them. md5 is just being used as a pseudorandom number generator here, and it has a very small-entropy seed (someone call Debian!). So its cryptographic strenth isn't particularly relevant. --Xkcd 07:43, 21 May 2008 (UTC)xkcd

OMG geohashing predicts future dow prices!

http://irc.peeron.com/xkcd/map/data/2009/05/27 --Ryan the leach 12:33, 21 May 2008 (UTC)

heh yeh i saw that one too... this is deep magic SinJax

Yeah, I totally wasn't testing stuff, <_< Zigdon 14:54, 21 May 2008 (UTC)

Wow, now you only need to break MD5 to get rich! 81.167.17.12 12:40, 21 May 2008 (UTC)

could be future meetup? --Ryan the leach 12:33, 21 May 2008 (UTC)

Fairly inconsistent if so, what if the dow is different. WHAT THEN?!?

It won't ;) --DarkRat

well the tool wont say its different :P --Ryan the leach 12:33, 21 May 2008 (UTC)

geohash.org

There's already a thing called "geohash" which is a way to represent coordinates with arbitrary precision in a computer and query-friendly format. It's at http://geohash.org/ and it was designed and implemented by Gustavo Niemeyer.

I don't see how that's relevant. We are talking about geohashing. It's a different word.

To decimal

...now, i'm likely just too thick to get it, but how does one convert back from the half md5 hash to decimals?

It goes like this... each digit is below zero but not 10^-n but 16^-n....so the first hex digit is 16^-1, the next is 16^-2 and so on. And it goes from left to right so in the hex number "8d" you get:

f = (8 * 16^-1) + (13 * 16^-2) = 0.5507

i think anyway :) - SinJax

Or, interpret the bytes from md5 as two big-endian 64-bit integers, and divide both by 2^64.