Re: Recommendations on image verification libraries?

..oO(laredotornado@xxxxxxxxxxx)

I'm using PHP 4.4.4. I want to block automatic submissions from
spammers on our web site, so I'd like to use some PHP libraries that
generate those image graphics and require the user to type the
characters in the graphics.

That's called a CAPTCHA, in this case a graphical one.

Do you have any recommendations on things
you have used that are easy to implement and effective?

No, and I won't use them. There are various accessibility problems with
these graphical CAPTCHAs:

Inaccessibility of CAPTCHA
http://www.w3.org/TR/turingtest/

This link also discusses some alternatives to the inaccessible graphical
CAPTCHAs.

Additionally many of the available implementations are already broken
and can be read by machines:

Breaking a Visual CAPTCHA
http://www.cs.sfu.ca/~mori/research/gimpy/

PWNtcha - captcha decoder
http://sam.zoy.org/pwntcha/

aiCaptcha - Using AI to beat CAPTCHA and post comment spam
http://www.brains-n-brawn.com/default.aspx?vDir=aicaptcha

XRumer (CAPTCHA breaking spam poster)
http://pandalabs.pandasecurity.com/archive/XRumer.aspx

Micha
.