RE: Had an idea - looking for a math buff to tell me if it's possiblewith today's technology.

["Jamie Bowden" <jamie () photon com>]

I know you're having fun with him, but I think what the original poster
had in mind was more like thinking of a file as just a string of
numbers.  Create an equation that generates that string of numbers, send
equation, regenerate string on other end.  Of course, if it was that
easy, someone would already have done it (or who knows, IBM might have
done this decades ago, put it on a virtual shelf in their IP closet, and
forgot about it...apparently they do that sort of thing all the time).
Compression is mathematically akin to cryptography, with the compressed
file being a huge seed with a standard algorithm (and a very weak one by
modern cryptography standards, sure, but imagine someone trying to
figure out a .zip file in the 50s).

Jamie

-----Original Message-----
From: Leo Bicknell [mailto:bicknell () ufp org] 
Sent: Wednesday, May 18, 2011 5:03 PM
To: nanog
Subject: Re: Had an idea - looking for a math buff to tell me if it's
possiblewith today's technology.

In a message written on Wed, May 18, 2011 at 04:33:34PM -0400,
Christopher Morrow wrote:
> no no no.. it's simply, since the OP posited a math solution, md5.
> ship the size of file + hash, compute file on the other side. All
> files can be moved anywhere regardless of the size of the file in a
> single packet.
>
>
> The solution is left as an exercise for the reader.

Bah, you should include the solution, it's so trivial.

Generate all possible files and then do an index lookup on the MD5.
It's a little CPU heavy, but darn simple to code.

You can even stop when you get a match, which turns out to be a HUGE
optimization. :)

-- 
       Leo Bicknell - bicknell () ufp org - CCIE 3440
        PGP keys at http://www.ufp.org/~bicknell/