Devious linkage to enter Web site

[Guest]

I've been having all sorts of problems with spam/porn in my genealgy Guestbook. I found an interesting page today that gets around crawlers (hopefully) by a technique I can't figure out from the raw HTML code, which seems basic and simple.

Clicking on an image and asking people to sign in by a word in the image admits you. It sounds like what I'm looking for without going to JS or Java.

Can someone help please?

Thanks,
Don
Username munged by FixNews

 

[Guest]

I've been having all sorts of problems with spam/porn in my genealgy Guestbook. I found an interesting page today that gets around crawlers (hopefully) by a technique I can't figure out from the raw HTML code, which seems basic and simple.
http://www.sonic.net/~melvaw/

Clicking on an image and asking people to sign in by a word in the image admits you. It sounds like what I'm looking for without going to JS or Java.

Can someone help please?

Thanks,
Don

Username munged by FixNews

 

[Hywel]

I've been having all sorts of problems with spam/porn in my genealgy Guestbook. I found an interesting page today that gets around crawlers (hopefully) by a technique I can't figure out from the raw HTML code, which seems basic and simple.

Clicking on an image and asking people to sign in by a word in the image admits you. It sounds like what I'm looking for without going to JS or Java.

Can someone help please?

Do it with a bit of PHP and the GD or GD2 library.

 

[brucie]

in post: <

I've been having all sorts of problems with spam/porn in my genealgy
Guestbook. [...] Clicking on an image and asking people to sign in by
a word in the image admits you.

what you're looking for is a CAPTCHA[1] script. while they look like
they're effective against non-humans they're not. rates for successfully
cracking them are around 80-95% depending on the method CAPTCHA used to
generate the image.

if you implemented CAPTCHA i don't think anyone would go to the effort
of cracking it just to spam a guestbook so you're probably safe. in fact
you could probably get away without it. just use a normal image changed
every week or so. on the form ask people to enter the text on the image.
simple.

[1]
CAPTCHA - Completely Automated Public Turing test to Tell Computers and
Humans Apart

OCR CAPTCHA
http://phpclasses.dknss.com/browse/package/1538.html
HN CAPTCHA
http://phpclasses.dknss.com/browse/package/1569.html
hn demo:
http://www.nogajski.de/horst/php/captcha/index.php