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RE: Text-based Captchas

From: Mark | Carbon Chip <mark@carbonchip.com>
Date: Wed, 3 May 2006 11:56:05 +0100
To: "'WAI Interest Group'" <w3c-wai-ig@w3.org>
Message-ID: <006a01c66ea0$2d02d1a0$0400a8c0@norris>

Has anyone done anything with Flash in conjunction with images? I started
some work on a Flash system which automatically played a Captcha audio file
that correlated with the Captcha image.

I mention Flash, not wishing to incur any wrath :), but just as an
augmentation to image based Captchas. Obviously user control isn't there,
and to hear the audio again, the user would have to refresh the page, and
invariably have a different character sequence read to them, but possible
advantages are:

1. Augmentation only, would add to image Captcha method.
2. Lack of Flash player should not impair the procedure.
3. Flash may have a benefit over serving up audio files, in that another
application would not need to be opened (eg if .MP3 served instead).
4. Very customisable - would not need to run a server side script to process
and stitch audio files together - Flash could handle this, and different
voice libraries (of higher/lower quality) could easily be added as required.

Drawbacks:

1. Surprise to user - no control, unless directed to a separate page and
informed of what is going to happen.
2. Plug-in dependent.

I hadn't seen any type of open source server-side audio manipulation tool,
and guessed that it would be quite server intensive and require privileges
that many site owners would not have, hence Flash.

Mark

-----Original Message-----
From: w3c-wai-ig-request@w3.org [mailto:w3c-wai-ig-request@w3.org] On Behalf
Of David Poehlman
Sent: 03 May 2006 11:30
To: Patrick Lauke
Cc: WAI Interest Group
Subject: Re: Text-based Captchas


I found a really interesting one at:
http://www.usps.gov
where you change your mailing adddress.  If you go to change address, they
have a link that will provide you with the string in the clear.

On May 3, 2006, at 4:39 AM, Patrick Lauke wrote:

> Matthew Smith

> Appropriate links are here:
> <http://www.smiffysplace.com/blog/archives/169-php-text-captcha>

Although the question are fairly simple, entailing nothing more than "common
knowledge", it's still possible that some geniune user may not know the
answer to them.

More generally, users may actually be confused by finding any sort of
question not related to the task they're trying to achieve (I want to book a
flight, why is it asking me who the President of the US is?), so this may
require a careful bit of preamble/legend, perhaps.

But regardless, nice one.

P
________________________________
Patrick H. Lauke
Web Editor / University of Salford
http://www.salford.ac.uk
________________________________
Web Standards Project (WaSP) Accessibility Task Force
http://webstandards.org/ ________________________________
Received on Wednesday, 3 May 2006 10:56:14 GMT

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