12 ms·
Captchas are there to prevent bots which are making thousands or millions of submissions. With a timer the bot just needs to make all of the captcha requests fi
by ahsima1 5y ago
Captchas are there to prevent bots which are making thousands or millions of submissions. With a timer the bot just needs to make all of the captcha requests first and then wait 30 seconds for all of the timers to expire in parallel. But with proof of work the spammer actually needs to compute all of the work for every submission, which would require a significant amount of computational power, rendering some types of bots uneconomical to run.
- kazinator 5y agoExcellent point! It's not hard for a single attacking context to have the resources to generate vast numbers of requests in parallel. If a botnet is involved, it can use different originating IP addresses. And so, that's why we need proof of work; thank you for bringing my derailed narrative back on the proper technical track.