Think cash

Adam Back adam@cypherspace.org
Fri, 9 Mar 2001 04:28:47 -0400


A friend of mine had a go at building such a puzzle to
deter automated downloads of activation codes.  He built a
prototype.

It was just a pattern matching problem.  It would take a
set of numbers draw them in a pixel array and munge it
around a bit, scatter random pixels over it.  Humans can
easily read off the number.  It would take a bit of effort
to build OCR software that can read through that noise. 
But I'm pretty sure it could be done if somone were
motivated.

You see a similar thing where people render their email
addresses as a GIF to hide it from spiders.

Adam

On Fri, Mar 09, 2001 at 02:17:47AM -0600, Tony Kimball wrote:
> 
> It seems not so hard to me.
> 
> For example, abstractly, the computer can make a picture, and ask a 
> question about it which requires significant understanding,
> and parse the reply trivially.