- see footer for list info -<
"The only difficulty would this is get-aroundable by bots, assuming any bot
writer cares enough about your site to spend the time rewriting their bot to
regex your form field to get the magic word."

Aha - so don't use words, use images.

I've done this before, and its a little fiddly, but practically 100% spam
safe.

On the page hit, read a directory full of images that have magic words
written on them, the file called the same as the magic word.

Get a random one of those filenames:
<cfset session.secureImageName = qryImageNames.name[randrange(1,
qryImageNames.recordcount)]>

set that to a session and display the image in the form - however, don't
display it using simple <img src="images/secureImages/HYU78.jpg">

instead, use a CF page that serves up an image with the appropriate mimetype
using cfcontent

<img src="serveSecureImage.cfm">

In serveSecureImage.cfm, you read the session variable (
session.secureImageName) you set before and return that using cfcontent.
This means that bots can't simply read the html on the page and find the
filename and use that in the input as the magic word.

Alternatively, use an image making tag to write a randomly pulled magic word
from a database or equivalent and simply serve that - this way just stops
you having to have a directory full of images, but I had fun making those.

If the magic word posted in the form don't fit the served image - don't send
the mail!

Richio McStitchio
Chief Neckchief
http://www.theideasbarn.com


On 8/16/06, Duncan Cumming <[EMAIL PROTECTED]> wrote:

>- see footer for list info -<
I'm not a fan of captchas.  Generally inacessible, unless you also make an
audio version available, and even then not the nicest hoop to make users
jump through.

One method I've seen elsewhere, but haven't used myself, is an additional
input box:
The magic word is blah.  Please enter the magic word.

The only place I've seen this method is the mysociety sites, e.g:
http://www.mysociety.org/?p=103

The only difficulty would this is get-aroundable by bots, assuming any bot
writer cares enough about your site to spend the time rewriting their bot to
regex your form field to get the magic word.


Duncan Cumming
New Media Developer
Customer Relations Management / Education
Fife Council
700 4105 / 01592 414105

>>> [EMAIL PROTECTED] 16/08/2006 14:25 >>>
>- see footer for list info -<
Hi all.

I have a contact form which submits an email (cfmail)
The form is being hit by a web bot and sent hundreds of times

Is there any way I can stop this?

regards - paul


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