Hacker News new | comments | show | ask | jobs | submit login

I wonder if a Javascript based proof-of-work system could be used as an alternative to CAPTCHAs. It wouldn't stop spam entirely but it would rate-limit it and possibly render some forms of spam unprofitable. Aa a bonus, the proof-of-work could be tied to something useful (Folding@home?) just like reCAPTCHA's CAPTCHAs are useful for digitizing books.

Nope. This was tried with Bitcoin back in the day. JavaScript is far too slow, and a spammer could just blast out thousands of times the work with a single CPU running something native. Mobile users would suffer greatly too.

Guidelines | FAQ | Support | API | Security | Lists | Bookmarklet | Legal | Apply to YC | Contact