SPAM Problems

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Vegan
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SPAM Problems

Post by Vegan »

I have tried a few idea to stamp out spammers on my sites and trust me it has been a monumental headache.

Of late I am trying a random picture background to frustrate OCR attacks and have found a modicum of success. I expect that idea to fail eventually.

Can PHP help me generate say a 3D version of a CAPTCHA? How about taking an image and rotating it by some random amount before displaying it.

I am working specifically to stamp out spammers once and for all.

Check out my current efforts: http://contract-developer.dyndns.biz where my forum has been spam free for weeks.

I wanted some more aggressive tactics before the spammers come back.
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McInfo
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Re: SPAM Problems

Post by McInfo »

I have had success with using a unique key based on the current time. The key is first generated on the page where the hyperlink to the form page is. It is passed as a GET variable when the user clicks the link to the form page. If the GET key passes validation, it is stored as a hidden input in the form. When the user submits the form, the key is passed as a POST variable. If the POST key passes validation, the form is processed.

This process ensures that the user started the transaction on your site and on some page other than the form page.

You could implement something like this in addition to your existing captcha.

Edit: This post was recovered from search engine cache.
Last edited by McInfo on Tue Jun 15, 2010 12:36 pm, edited 1 time in total.
BornForCode
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Re: SPAM Problems

Post by BornForCode »

You can try a different system then a captcha, for example you may try to ask a question upon registration. Or you can mix this with captcha by using a match operation captcha, for example 23-1 = ?
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Vegan
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Re: SPAM Problems

Post by Vegan »

I have looked at those ideas. I am looking at session locks to be sure the bots do not try to circumvent the registration code. At present phpBB has a session ID and that seems to be working.

So anyone got some advanced graphics code to share?
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