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Re: Captcha and inaccessiblity

From: Matt May <mcmay@w3.org>
Date: Mon, 20 Oct 2003 09:00:29 -0700
Cc: "Charles McCathieNevile" <charles@w3.org>, "Tom Croucher" <tcroucher@netalleynetworks.com>, <w3c-wai-gl@w3.org>
To: <gdeering@acslink.net.au>
Message-Id: <87036D00-0316-11D8-9F6C-000393B628BC@w3.org>

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 12:00:58 GMT

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