Re: CAPTCHA image validation in web form

I'll be interested in this too. I've never done it, and could most likely
figure it out, but I'm sure one of the days one of my customers is going to
want it. :)

I had issues with bots on my website forum software one time. I almost
looked into it then, but instead created a simple onSubmit javascript that
threw up a dialog saying "do you really want to post this?" and when they
clicked OK it changed another variable and went into my CGI app. That way
it couldn't by bypassed unless they figured out what the name of the
variable I changed and the value was.

Worked for a year, but one spammer actually figured it out and changed their
bot. I was like "well, someone is sure bored!" lol..

Bradley V. Stone
BVSTools - www.bvstools.com
eRPG SDK - www.erpgsdk.com

-----Original Message-----
From: web400-bounces@xxxxxxxxxxxx [mailto:web400-bounces@xxxxxxxxxxxx]On
Behalf Of Nathan Andelin
Sent: Monday, September 01, 2008 10:06 AM
To: Web Enabling the AS400 / iSeries
Subject: Re: [WEB400] CAPTCHA image validation in web form


I've never output a form that prompted the user to enter the
characters represented in a Captcha image. But if you had a
table on your server that cross-referenced the character
representation with the image file name, the validation logic
would just be a regular string comparison against the appropriate
table row & column, and the type of thing you could easily do in
just about any server language.

I understand that the purpose of distorting the image is to
prevent it from being converted to a character string via
standard optical character recognition, which could be employed
via bot. You want to make sure the user is more intelligent
(human) than a bot.

So my question would be, is there software available that can
convert simple character strings into distorted image
representation, so you can generate your own table of prompts?

Nathan.






----- Original Message ----
From: "Guillermo Andrades, CPI Software" <gab@xxxxxxx>
To: Web Enabling the AS400 / iSeries <web400@xxxxxxxxxxxx>
Sent: Sunday, August 31, 2008 1:39:47 PM
Subject: [WEB400] CAPTCHA image validation in web form

some experiences using captcha image validation in web forms?
please not php not python not java....
(btw, info about captcha in wikipedia:
http://en.wikipedia.org/wiki/Captcha)

Interested in some way of web services or having a full directory with
images or so on, some not requering script in the host (RPG code,
even C or
C++ will be welcome).

The intend use is an not-as-secure-as-FBI form, thus: don't need
double nor
complex validation.
client side is html+javascript, host is RPGIV.

Thanks in advance,
Guillermo.



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