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RE: Captcha and inaccessiblity

From: Geoff Deering <gdeering@acslink.net.au>
Date: Tue, 21 Oct 2003 05:59:30 +1000
To: "Matt May" <mcmay@w3.org>
Cc: "Charles McCathieNevile" <charles@w3.org>, "Tom Croucher" <tcroucher@netalleynetworks.com>, <w3c-wai-gl@w3.org>
Message-ID: <NBBBJPNFCLNLAADCLFJBOENIFBAA.gdeering@acslink.net.au>

That's great.

FYI There's also a discussion on the same subject addressing accessibility
over at slashdot


-----Original Message-----
From: Matt May

On Sunday, October 19, 2003, at 03:39  PM, Geoff Deering wrote:
> I think there is a need for a "Techniques for Accessible Form Handling"
> document or the like so that developers are given viable alternatives
> to
> prevent machine spamming of forms.

The WAI Protocols and Formats Working Group has been working on a
document specifically addressing CAPTCHA, and hopes to submit a draft
Note for the Technical Reports page[1] this week. It describes the
problems inherent in CAPTCHA, and seven categories of potential
solutions, including logic or word puzzles, server heuristics, and
public-key infrastructure.

I would hesitate to have a detailed discussion in WCAG about CAPTCHA,
since it is a technique with documented exploits which limit its
lifespan to perhaps only another year or two. The researchers behind
CAPTCHA are already working on alternative approaches themselves.
Further, this design already fails both versions of WCAG (and every
evaluation tool) because it doesn't offer alt text for a necessary
textual component.

I will let this list know when the document is up.

[1] http://www.w3.org/TR/
Received on Monday, 20 October 2003 16:00:01 UTC

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