Funny coincidence I made the similar thing into a webcomponent a few weeks ago for a different purpose: click-to-reveal buttons to prevent scraping of public em

Funny coincidence I made the similar thing into a webcomponent a few weeks ago for a different purpose: click-to-reveal buttons to prevent scraping of public emails in static websites. It works by encrypting the content using the same deriveKey method varying the iterations to determine time 'cost'. Imo it's not really fit for most captchas situations since you can easily parallelize the execution by simply running multiple tabs/browsers or even hooking crypto/subtle up to an GPU/ASIC with a bit of hackery.