Re: Going from simple to super CAPTCHA
| From: | Richard Lynch | Date: | Tue, 12 Jun 2007 21:05:26 +0000 |
| Subject: | Re: Going from simple to super CAPTCHA | ||
| References: | 1 2 3 4 5 6 7 8 9 10 11 12 13 | Groups: | php.general |
| Request: | Send a blank email to php-general+get-256787@lists.php.net to get a copy of this message | ||
On Tue, June 12, 2007 7:01 am, tedd wrote:
> I was thinking about this the other day -- computers are fast and
> people are generally slow. So, instead of making the time short,
> examine how fast the answer was obtained. Immediate = computer;
> delayed = human.
>
> Even an easy LETTER CAPTCHA takes time for a human, but a computer
> can recognize and respond much quicker.
>
> I know, spammy can delay his bot's response, but it's just a
> difference between computer/human to consider.
Some sites already employ this kind of thing to stop badly-written
robots from pounding their server.
OTOH, wget has a random delay built-in to defeat this kind of thing.
So somebody somewhere will figure out that's what the trick is, and
write code to bypass it.
So, as before, *ANY* captcha you use will stop the bulk of spam.
*ANY* captcha you use is crackable by somebody somewhere.
--
Some people have a "gift" link here.
Know what I want?
I want you to buy a CD from some indie artist.
http://cdbaby.com/browse/from/lynch
Yeah, I get a buck. So?