It will not scare away bots but 10 seconds of wait (CPU or only a sleep) will turn away many real users. "This site is so slow, I'll use something else." A kind of reverse captcha.
It will not scare away bots but 10 seconds of wait (CPU or only a sleep) will turn away many real users. "This site is so slow, I'll use something else." A kind of reverse captcha.
Maybe, the proof of work can run in the background.
Or it can run as part of a checkout wizard's "verifying your browser and processing your payment, don't close your tab" step.