Antwort: Re: [PHP] 3 mins of your time please...logic problem
| From: | SLanger at spirit21 dot de | Date: | Thu, 25 Sep 2003 13:42:15 +0000 |
| Subject: | Antwort: Re: [PHP] 3 mins of your time please...logic problem | ||
| References: | 1 | Groups: | php.general |
| Request: | Send a blank email to php-general+get-163899@lists.php.net to get a copy of this message | ||
I agree that an image captcha can not be cracked by a lot of people,
allthough it has been done. (and it takes only one program being released
to do the job : ) ) Somethings to keep in mind is that you should use
passphrases made up of random letters and numbers preventing the automated
system from guessing them.
The text captcha is based on the idea that the question you ask has to be
interpreted first. I admit my question was not the best example but it
should give an idea. A (maybe) better example:
The author Frank Example is 35 years old.
He studies Law at Harvard.
BTW he says "Hi".
,
What does the author Frank say?
In a real world app this would be contained in a much larger text block
and the question and text would be changed on each attempt.
If you have a wide enough base of such questions it becomes virtually
impossible to guess the correct word leaving only a brute force attack.
A text captcha is fairly easy to set up using mysql and php but if you
have a image captcha generator go with it or better even combine the two,
it all depends on the grade of security you need against automation.
regards
Stefan Langer