| 
	
 | 
 Posted by tom pester on 09/08/05 03:10 
Hi Phil, 
 
> Now I have the answer to your addition sum, and the session ID from 
> your "hidden" field. That wasn't difficult, was it? 
 
> Turing numbers are nowhere near as vulnerable. Implemented properly, 
> they are impossible for computers to read successfully without a lot 
> of hard work targeted at each specific implementation. 
 
I asked for another way but thx for the script anyway... 
I know it's easy to parse the numbers but can you think of another way to  
abuse that page. 
 
Again, my point is that turing numbers are a good solution _now_  and I will  
use them in a commercial site. 
But it's only a matter of time before computers can read turing numbers as  
easily as tehy do addition now. 
 
And this page isn't easily exploitable by a bot either. The spammer's bots  
won't find this page automaticaly and if he stumbles upon it he has to do  
some custom coding. I think he will go and look for an eaiser alternative  
(which are plentyful). 
 
There are other alternatives that are cost based in which the difficulty  
of parsing a test outweighs the profit a spammer makes. 
I remember reading a good article in scientific american about it. 
 
Anyway, this is an exercice of me in making it as secure as possible with  
the known limitation that a simple parsing circomvents it if the spammer  
takes the trouble (which he won't ;) 
Can you look at my question this way and see if there is a flaw in it?
 
  
Navigation:
[Reply to this message] 
 |