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Redraft of CAPTCHA Conclusion Section

From: Janina Sajka <janina@rednote.net>
Date: Wed, 16 Jan 2019 09:48:55 -0500
To: public-rqtf@w3.org
Message-ID: <20190116144855.GG1915@rednote.net>
As discussed in the call today ...


CAPTCHA has evolved over time. This has included the development of
several alternatives to text-based characters contained in bitmapped
images, some of which can serve to support access for persons with
disabilities. However, it has also been demonstrated not only that
traditional CAPTCHA continues to be challenging for people with
disabilities, but also increasingly insecure and arguably now ill suited
to the purpose of distinguishing human individuals from their robotic

Yet the need for a solution persists and will continue to persist.  It is
therefore highly recommended that the purpose and effectiveness of any
deployed solution be carefully considered before adoption, and then closely
monitored for effective performance. As with all good software and on line
content provisioning, analysis should begin with a careful consideration of
system requirements and a thorough profiling of user needs.

Clearly, some solutions such as Google's reCAPTCHA, Facebook Connect,
two-step or multi-device verification can be easily and affordably
deployed. Yet problems persist even in these systems, especially for non
English speakers.  Furthermore, it must be acknowledged by anyone who
deploys such a solution that they are also participating in exposing
their users to a massive collection of personal data across multiple
trans-national big data systems and quite apart from any regulatory

It is important, therefore, also to consider available stand-alone solutions such
as honeypots and heuristics, along with current image and aural CAPTCHA
libraries that support multiple languages. As always, testing and system monitoring for
effectiveness should supply the ultimate determination, even as we recognize
that an effective system today may prove ineffective a few years from now.

In other words, while some CAPTCHA solutions are better than others, there is currently no ideal solution. It is important to exercise care that any implemented CAPTCHA
technology correctly identify people with disabilities as human.


Janina Sajka

Linux Foundation Fellow
Executive Chair, Accessibility Workgroup:	http://a11y.org

The World Wide Web Consortium (W3C), Web Accessibility Initiative (WAI)
Chair, Accessible Platform Architectures	http://www.w3.org/wai/apa
Received on Wednesday, 16 January 2019 14:49:18 UTC

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