Working Draft Feedback: Missing proof of work based solutions

[ukd1]

This is missing proof of work based solutions - these slow down spammers by changing the amount of work they can do in a given time, making a site using them less profitable per attack.

Upsides; non-interactive, will always work eventually with JS enabled, no obvious human language issue or accessibility issues. Downsides; takes longer on slower computers (phones, older machines), doesn't actually stop spam - just makes it less profitable per unit of compute

Examples:

• https://github.com/xenohunter/lapti-pow-captcha
• https://github.com/trikota/flask_hashcash
• http://www.hashcash.org/

[JaninaSajka]

Thank you, Russell. We've added a Proof of Work section here: https://w3c.github.io/apa/captcha/#proof-of-work-techniques Please let us know if you think we missed anything, or if you think we've not fully captured the relevance for CAPTCHA. Best, Janina Russell Smith writes:

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This is missing proof of work based solutions - these slow down spammers by changing the amount of work they can do in a given time, making a site using them less profitable per attack. Upsides; non-interactive, will always work eventually with JS enabled, no obvious human language issue or accessibility issues. Downsides; takes longer on slower computers (phones, older machines), doesn't actually stop spam - just makes it less profitable per unit of compute Examples: * https://github.com/xenohunter/lapti-pow-captcha * https://github.com/trikota/flask_hashcash * http://www.hashcash.org/ -- You are receiving this because you are subscribed to this thread. Reply to this email directly or view it on GitHub: w3c/captcha-accessibility#26

-- 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